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partial slab sanitization heuristic #12

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thestinger opened this issue May 11, 2017 · 2 comments
Closed

partial slab sanitization heuristic #12

thestinger opened this issue May 11, 2017 · 2 comments

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@thestinger
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thestinger pushed a commit that referenced this issue May 12, 2017
commit 4dfce57 upstream.

There have been several reports over the years of NULL pointer
dereferences in xfs_trans_log_inode during xfs_fsr processes,
when the process is doing an fput and tearing down extents
on the temporary inode, something like:

BUG: unable to handle kernel NULL pointer dereference at 0000000000000018
PID: 29439  TASK: ffff880550584fa0  CPU: 6   COMMAND: "xfs_fsr"
    [exception RIP: xfs_trans_log_inode+0x10]
 #9 [ffff8800a57bbbe0] xfs_bunmapi at ffffffffa037398e [xfs]
#10 [ffff8800a57bbce8] xfs_itruncate_extents at ffffffffa0391b29 [xfs]
#11 [ffff8800a57bbd88] xfs_inactive_truncate at ffffffffa0391d0c [xfs]
#12 [ffff8800a57bbdb8] xfs_inactive at ffffffffa0392508 [xfs]
#13 [ffff8800a57bbdd8] xfs_fs_evict_inode at ffffffffa035907e [xfs]
#14 [ffff8800a57bbe00] evict at ffffffff811e1b67
#15 [ffff8800a57bbe28] iput at ffffffff811e23a5
#16 [ffff8800a57bbe58] dentry_kill at ffffffff811dcfc8
#17 [ffff8800a57bbe88] dput at ffffffff811dd06c
#18 [ffff8800a57bbea8] __fput at ffffffff811c823b
#19 [ffff8800a57bbef0] ____fput at ffffffff811c846e
#20 [ffff8800a57bbf00] task_work_run at ffffffff81093b27
#21 [ffff8800a57bbf30] do_notify_resume at ffffffff81013b0c
#22 [ffff8800a57bbf50] int_signal at ffffffff8161405d

As it turns out, this is because the i_itemp pointer, along
with the d_ops pointer, has been overwritten with zeros
when we tear down the extents during truncate.  When the in-core
inode fork on the temporary inode used by xfs_fsr was originally
set up during the extent swap, we mistakenly looked at di_nextents
to determine whether all extents fit inline, but this misses extents
generated by speculative preallocation; we should be using if_bytes
instead.

This mistake corrupts the in-memory inode, and code in
xfs_iext_remove_inline eventually gets bad inputs, causing
it to memmove and memset incorrect ranges; this became apparent
because the two values in ifp->if_u2.if_inline_ext[1] contained
what should have been in d_ops and i_itemp; they were memmoved due
to incorrect array indexing and then the original locations
were zeroed with memset, again due to an array overrun.

Fix this by properly using i_df.if_bytes to determine the number
of extents, not di_nextents.

Thanks to dchinner for looking at this with me and spotting the
root cause.

Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
thestinger pushed a commit that referenced this issue May 12, 2017
[ Upstream commit 45caeaa ]

As Eric Dumazet pointed out this also needs to be fixed in IPv6.
v2: Contains the IPv6 tcp/Ipv6 dccp patches as well.

We have seen a few incidents lately where a dst_enty has been freed
with a dangling TCP socket reference (sk->sk_dst_cache) pointing to that
dst_entry. If the conditions/timings are right a crash then ensues when the
freed dst_entry is referenced later on. A Common crashing back trace is:

 #8 [] page_fault at ffffffff8163e648
    [exception RIP: __tcp_ack_snd_check+74]
.
.
 #9 [] tcp_rcv_established at ffffffff81580b64
#10 [] tcp_v4_do_rcv at ffffffff8158b54a
#11 [] tcp_v4_rcv at ffffffff8158cd02
#12 [] ip_local_deliver_finish at ffffffff815668f4
#13 [] ip_local_deliver at ffffffff81566bd9
#14 [] ip_rcv_finish at ffffffff8156656d
#15 [] ip_rcv at ffffffff81566f06
#16 [] __netif_receive_skb_core at ffffffff8152b3a2
#17 [] __netif_receive_skb at ffffffff8152b608
#18 [] netif_receive_skb at ffffffff8152b690
#19 [] vmxnet3_rq_rx_complete at ffffffffa015eeaf [vmxnet3]
#20 [] vmxnet3_poll_rx_only at ffffffffa015f32a [vmxnet3]
#21 [] net_rx_action at ffffffff8152bac2
#22 [] __do_softirq at ffffffff81084b4f
#23 [] call_softirq at ffffffff8164845c
#24 [] do_softirq at ffffffff81016fc5
#25 [] irq_exit at ffffffff81084ee5
#26 [] do_IRQ at ffffffff81648ff8

Of course it may happen with other NIC drivers as well.

It's found the freed dst_entry here:

 224 static bool tcp_in_quickack_mode(struct sock *sk)↩
 225 {↩
 226 ▹       const struct inet_connection_sock *icsk = inet_csk(sk);↩
 227 ▹       const struct dst_entry *dst = __sk_dst_get(sk);↩
 228 ↩
 229 ▹       return (dst && dst_metric(dst, RTAX_QUICKACK)) ||↩
 230 ▹       ▹       (icsk->icsk_ack.quick && !icsk->icsk_ack.pingpong);↩
 231 }↩

But there are other backtraces attributed to the same freed dst_entry in
netfilter code as well.

All the vmcores showed 2 significant clues:

- Remote hosts behind the default gateway had always been redirected to a
different gateway. A rtable/dst_entry will be added for that host. Making
more dst_entrys with lower reference counts. Making this more probable.

- All vmcores showed a postitive LockDroppedIcmps value, e.g:

LockDroppedIcmps                  267

A closer look at the tcp_v4_err() handler revealed that do_redirect() will run
regardless of whether user space has the socket locked. This can result in a
race condition where the same dst_entry cached in sk->sk_dst_entry can be
decremented twice for the same socket via:

do_redirect()->__sk_dst_check()-> dst_release().

Which leads to the dst_entry being prematurely freed with another socket
pointing to it via sk->sk_dst_cache and a subsequent crash.

To fix this skip do_redirect() if usespace has the socket locked. Instead let
the redirect take place later when user space does not have the socket
locked.

The dccp/IPv6 code is very similar in this respect, so fixing it there too.

As Eric Garver pointed out the following commit now invalidates routes. Which
can set the dst->obsolete flag so that ipv4_dst_check() returns null and
triggers the dst_release().

Fixes: ceb3320 ("ipv4: Kill routes during PMTU/redirect updates.")
Cc: Eric Garver <egarver@redhat.com>
Cc: Hannes Sowa <hsowa@redhat.com>
Signed-off-by: Jon Maxwell <jmaxwell37@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
thestinger pushed a commit that referenced this issue Jun 24, 2017
commit ba80aa9 upstream.

This patch closes a long standing race in configfs between
the creation of a new symlink in create_link(), while the
symlink target's config_item is being concurrently removed
via configfs_rmdir().

This can happen because the symlink target's reference
is obtained by config_item_get() in create_link() before
the CONFIGFS_USET_DROPPING bit set by configfs_detach_prep()
during configfs_rmdir() shutdown is actually checked..

This originally manifested itself on ppc64 on v4.8.y under
heavy load using ibmvscsi target ports with Novalink API:

[ 7877.289863] rpadlpar_io: slot U8247.22L.212A91A-V1-C8 added
[ 7879.893760] ------------[ cut here ]------------
[ 7879.893768] WARNING: CPU: 15 PID: 17585 at ./include/linux/kref.h:46 config_item_get+0x7c/0x90 [configfs]
[ 7879.893811] CPU: 15 PID: 17585 Comm: targetcli Tainted: G           O 4.8.17-customv2.22 #12
[ 7879.893812] task: c00000018a0d3400 task.stack: c0000001f3b40000
[ 7879.893813] NIP: d000000002c664ec LR: d000000002c60980 CTR: c000000000b70870
[ 7879.893814] REGS: c0000001f3b43810 TRAP: 0700   Tainted: G O     (4.8.17-customv2.22)
[ 7879.893815] MSR: 8000000000029033 <SF,EE,ME,IR,DR,RI,LE>  CR: 28222242  XER: 00000000
[ 7879.893820] CFAR: d000000002c664bc SOFTE: 1
                GPR00: d000000002c60980 c0000001f3b43a90 d000000002c70908 c0000000fbc06820
                GPR04: c0000001ef1bd900 0000000000000004 0000000000000001 0000000000000000
                GPR08: 0000000000000000 0000000000000001 d000000002c69560 d000000002c66d80
                GPR12: c000000000b70870 c00000000e798700 c0000001f3b43ca0 c0000001d4949d40
                GPR16: c00000014637e1c0 0000000000000000 0000000000000000 c0000000f2392940
                GPR20: c0000001f3b43b98 0000000000000041 0000000000600000 0000000000000000
                GPR24: fffffffffffff000 0000000000000000 d000000002c60be0 c0000001f1dac490
                GPR28: 0000000000000004 0000000000000000 c0000001ef1bd900 c0000000f2392940
[ 7879.893839] NIP [d000000002c664ec] config_item_get+0x7c/0x90 [configfs]
[ 7879.893841] LR [d000000002c60980] check_perm+0x80/0x2e0 [configfs]
[ 7879.893842] Call Trace:
[ 7879.893844] [c0000001f3b43ac0] [d000000002c60980] check_perm+0x80/0x2e0 [configfs]
[ 7879.893847] [c0000001f3b43b10] [c000000000329770] do_dentry_open+0x2c0/0x460
[ 7879.893849] [c0000001f3b43b70] [c000000000344480] path_openat+0x210/0x1490
[ 7879.893851] [c0000001f3b43c80] [c00000000034708c] do_filp_open+0xfc/0x170
[ 7879.893853] [c0000001f3b43db0] [c00000000032b5bc] do_sys_open+0x1cc/0x390
[ 7879.893856] [c0000001f3b43e30] [c000000000009584] system_call+0x38/0xec
[ 7879.893856] Instruction dump:
[ 7879.893858] 409d0014 38210030 e8010010 7c0803a6 4e800020 3d220000 e94981e0 892a0000
[ 7879.893861] 2f890000 409effe0 39200001 992a0000 <0fe00000> 4bffffd0 60000000 60000000
[ 7879.893866] ---[ end trace 14078f0b3b5ad0aa ]---

To close this race, go ahead and obtain the symlink's target
config_item reference only after the existing CONFIGFS_USET_DROPPING
check succeeds.

This way, if configfs_rmdir() wins create_link() will return -ENONET,
and if create_link() wins configfs_rmdir() will return -EBUSY.

Reported-by: Bryant G. Ly <bryantly@linux.vnet.ibm.com>
Tested-by: Bryant G. Ly <bryantly@linux.vnet.ibm.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
thestinger pushed a commit that referenced this issue Jul 3, 2017
This patch closes a long standing race in configfs between
the creation of a new symlink in create_link(), while the
symlink target's config_item is being concurrently removed
via configfs_rmdir().

This can happen because the symlink target's reference
is obtained by config_item_get() in create_link() before
the CONFIGFS_USET_DROPPING bit set by configfs_detach_prep()
during configfs_rmdir() shutdown is actually checked..

This originally manifested itself on ppc64 on v4.8.y under
heavy load using ibmvscsi target ports with Novalink API:

[ 7877.289863] rpadlpar_io: slot U8247.22L.212A91A-V1-C8 added
[ 7879.893760] ------------[ cut here ]------------
[ 7879.893768] WARNING: CPU: 15 PID: 17585 at ./include/linux/kref.h:46 config_item_get+0x7c/0x90 [configfs]
[ 7879.893811] CPU: 15 PID: 17585 Comm: targetcli Tainted: G           O 4.8.17-customv2.22 #12
[ 7879.893812] task: c00000018a0d3400 task.stack: c0000001f3b40000
[ 7879.893813] NIP: d000000002c664ec LR: d000000002c60980 CTR: c000000000b70870
[ 7879.893814] REGS: c0000001f3b43810 TRAP: 0700   Tainted: G O     (4.8.17-customv2.22)
[ 7879.893815] MSR: 8000000000029033 <SF,EE,ME,IR,DR,RI,LE>  CR: 28222242  XER: 00000000
[ 7879.893820] CFAR: d000000002c664bc SOFTE: 1
                GPR00: d000000002c60980 c0000001f3b43a90 d000000002c70908 c0000000fbc06820
                GPR04: c0000001ef1bd900 0000000000000004 0000000000000001 0000000000000000
                GPR08: 0000000000000000 0000000000000001 d000000002c69560 d000000002c66d80
                GPR12: c000000000b70870 c00000000e798700 c0000001f3b43ca0 c0000001d4949d40
                GPR16: c00000014637e1c0 0000000000000000 0000000000000000 c0000000f2392940
                GPR20: c0000001f3b43b98 0000000000000041 0000000000600000 0000000000000000
                GPR24: fffffffffffff000 0000000000000000 d000000002c60be0 c0000001f1dac490
                GPR28: 0000000000000004 0000000000000000 c0000001ef1bd900 c0000000f2392940
[ 7879.893839] NIP [d000000002c664ec] config_item_get+0x7c/0x90 [configfs]
[ 7879.893841] LR [d000000002c60980] check_perm+0x80/0x2e0 [configfs]
[ 7879.893842] Call Trace:
[ 7879.893844] [c0000001f3b43ac0] [d000000002c60980] check_perm+0x80/0x2e0 [configfs]
[ 7879.893847] [c0000001f3b43b10] [c000000000329770] do_dentry_open+0x2c0/0x460
[ 7879.893849] [c0000001f3b43b70] [c000000000344480] path_openat+0x210/0x1490
[ 7879.893851] [c0000001f3b43c80] [c00000000034708c] do_filp_open+0xfc/0x170
[ 7879.893853] [c0000001f3b43db0] [c00000000032b5bc] do_sys_open+0x1cc/0x390
[ 7879.893856] [c0000001f3b43e30] [c000000000009584] system_call+0x38/0xec
[ 7879.893856] Instruction dump:
[ 7879.893858] 409d0014 38210030 e8010010 7c0803a6 4e800020 3d220000 e94981e0 892a0000
[ 7879.893861] 2f890000 409effe0 39200001 992a0000 <0fe00000> 4bffffd0 60000000 60000000
[ 7879.893866] ---[ end trace 14078f0b3b5ad0aa ]---

To close this race, go ahead and obtain the symlink's target
config_item reference only after the existing CONFIGFS_USET_DROPPING
check succeeds.

This way, if configfs_rmdir() wins create_link() will return -ENONET,
and if create_link() wins configfs_rmdir() will return -EBUSY.

Reported-by: Bryant G. Ly <bryantly@linux.vnet.ibm.com>
Tested-by: Bryant G. Ly <bryantly@linux.vnet.ibm.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Cc: stable@vger.kernel.org
thestinger pushed a commit that referenced this issue Jul 28, 2017
commit a117699 upstream.

The root cause of panic is the num_pm of nfit_test1 is wrong.
Though 1 is specified for num_pm at nfit_test_init(), it must be 2,
because nfit_test1->spa_set[] array has 2 elements.

Since the array is smaller than expected, the driver breaks other area.
(it is often the link list of devres).

As a result, panic occurs like the following example.

    CPU: 4 PID: 2233 Comm: lt-libndctl Tainted: G           O    4.12.0-rc1+ #12
    RIP: 0010:__list_del_entry_valid+0x6c/0xa0
    Call Trace:
     release_nodes+0x76/0x260
     devres_release_all+0x3c/0x50
     device_release_driver_internal+0x159/0x200
     device_release_driver+0x12/0x20
     bus_remove_device+0xfd/0x170
     device_del+0x1e8/0x330
     platform_device_del+0x28/0x90
     platform_device_unregister+0x12/0x30
     nfit_test_exit+0x2a/0x93b [nfit_test]

Signed-off-by: Yasunori Goto <y-goto@jp.fujitsu.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
@thestinger
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This is marked out-of-scope because the performance cost of full slab sanitization is cheap enough for CopperheadOS. I'm not sure if an implementation of the heuristic mode would be accepted, but I'm leaving open the issue because I'm still open to the possibility of providing that option. Changes spread out throughout the tree are a bit invasive but conflicts would be easy to handle by simply dropping any conflicting code temporarily.

There would need to be a justification for disabling sanitization for a given case. I'm not interested in a straight port of the chosen subset from PaX without providing reasoning / measurements justifying leaving it out for certain cases. It's quite useful as an exploit mitigation, not just purging sensitive data as quickly as possible which was their main reason for implementing it.

@thestinger
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I'm actually just going to close this. If people need more performance it can be done upstream.

thestinger pushed a commit that referenced this issue Nov 20, 2017
[ Upstream commit 6377ed0 ]

spin_lock/unlock of health->wq_lock should be IRQ safe.
It was changed to spin_lock_irqsave since adding commit 0179720
("net/mlx5: Introduce trigger_health_work function") which uses
spin_lock from asynchronous event (IRQ) context.
Thus, all spin_lock/unlock of health->wq_lock should have been moved
to IRQ safe mode.
However, one occurrence on new code using this lock missed that
change, resulting in possible deadlock:
  kernel: Possible unsafe locking scenario:
  kernel:       CPU0
  kernel:       ----
  kernel:  lock(&(&health->wq_lock)->rlock);
  kernel:  <Interrupt>
  kernel:    lock(&(&health->wq_lock)->rlock);
  kernel: #12 *** DEADLOCK ***

Fixes: 2a0165a ("net/mlx5: Cancel delayed recovery work when unloading the driver")
Signed-off-by: Moshe Shemesh <moshe@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
thestinger pushed a commit that referenced this issue Mar 31, 2018
[ Upstream commit 191f86c ]

The seg6_build_state() function is called with RCU read lock held,
so we cannot use GFP_KERNEL. This patch uses GFP_ATOMIC instead.

[   92.770271] =============================
[   92.770628] WARNING: suspicious RCU usage
[   92.770921] 4.16.0-rc4+ #12 Not tainted
[   92.771277] -----------------------------
[   92.771585] ./include/linux/rcupdate.h:302 Illegal context switch in RCU read-side critical section!
[   92.772279]
[   92.772279] other info that might help us debug this:
[   92.772279]
[   92.773067]
[   92.773067] rcu_scheduler_active = 2, debug_locks = 1
[   92.773514] 2 locks held by ip/2413:
[   92.773765]  #0:  (rtnl_mutex){+.+.}, at: [<00000000e5461720>] rtnetlink_rcv_msg+0x441/0x4d0
[   92.774377]  #1:  (rcu_read_lock){....}, at: [<00000000df4f161e>] lwtunnel_build_state+0x59/0x210
[   92.775065]
[   92.775065] stack backtrace:
[   92.775371] CPU: 0 PID: 2413 Comm: ip Not tainted 4.16.0-rc4+ #12
[   92.775791] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.2-1.fc27 04/01/2014
[   92.776608] Call Trace:
[   92.776852]  dump_stack+0x7d/0xbc
[   92.777130]  __schedule+0x133/0xf00
[   92.777393]  ? unwind_get_return_address_ptr+0x50/0x50
[   92.777783]  ? __sched_text_start+0x8/0x8
[   92.778073]  ? rcu_is_watching+0x19/0x30
[   92.778383]  ? kernel_text_address+0x49/0x60
[   92.778800]  ? __kernel_text_address+0x9/0x30
[   92.779241]  ? unwind_get_return_address+0x29/0x40
[   92.779727]  ? pcpu_alloc+0x102/0x8f0
[   92.780101]  _cond_resched+0x23/0x50
[   92.780459]  __mutex_lock+0xbd/0xad0
[   92.780818]  ? pcpu_alloc+0x102/0x8f0
[   92.781194]  ? seg6_build_state+0x11d/0x240
[   92.781611]  ? save_stack+0x9b/0xb0
[   92.781965]  ? __ww_mutex_wakeup_for_backoff+0xf0/0xf0
[   92.782480]  ? seg6_build_state+0x11d/0x240
[   92.782925]  ? lwtunnel_build_state+0x1bd/0x210
[   92.783393]  ? ip6_route_info_create+0x687/0x1640
[   92.783846]  ? ip6_route_add+0x74/0x110
[   92.784236]  ? inet6_rtm_newroute+0x8a/0xd0

Fixes: 6c8702c ("ipv6: sr: add support for SRH encapsulation and injection with lwtunnels")
Signed-off-by: David Lebrun <dlebrun@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
thestinger pushed a commit that referenced this issue Mar 31, 2018
[ Upstream commit 191f86c ]

The seg6_build_state() function is called with RCU read lock held,
so we cannot use GFP_KERNEL. This patch uses GFP_ATOMIC instead.

[   92.770271] =============================
[   92.770628] WARNING: suspicious RCU usage
[   92.770921] 4.16.0-rc4+ #12 Not tainted
[   92.771277] -----------------------------
[   92.771585] ./include/linux/rcupdate.h:302 Illegal context switch in RCU read-side critical section!
[   92.772279]
[   92.772279] other info that might help us debug this:
[   92.772279]
[   92.773067]
[   92.773067] rcu_scheduler_active = 2, debug_locks = 1
[   92.773514] 2 locks held by ip/2413:
[   92.773765]  #0:  (rtnl_mutex){+.+.}, at: [<00000000e5461720>] rtnetlink_rcv_msg+0x441/0x4d0
[   92.774377]  #1:  (rcu_read_lock){....}, at: [<00000000df4f161e>] lwtunnel_build_state+0x59/0x210
[   92.775065]
[   92.775065] stack backtrace:
[   92.775371] CPU: 0 PID: 2413 Comm: ip Not tainted 4.16.0-rc4+ #12
[   92.775791] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.2-1.fc27 04/01/2014
[   92.776608] Call Trace:
[   92.776852]  dump_stack+0x7d/0xbc
[   92.777130]  __schedule+0x133/0xf00
[   92.777393]  ? unwind_get_return_address_ptr+0x50/0x50
[   92.777783]  ? __sched_text_start+0x8/0x8
[   92.778073]  ? rcu_is_watching+0x19/0x30
[   92.778383]  ? kernel_text_address+0x49/0x60
[   92.778800]  ? __kernel_text_address+0x9/0x30
[   92.779241]  ? unwind_get_return_address+0x29/0x40
[   92.779727]  ? pcpu_alloc+0x102/0x8f0
[   92.780101]  _cond_resched+0x23/0x50
[   92.780459]  __mutex_lock+0xbd/0xad0
[   92.780818]  ? pcpu_alloc+0x102/0x8f0
[   92.781194]  ? seg6_build_state+0x11d/0x240
[   92.781611]  ? save_stack+0x9b/0xb0
[   92.781965]  ? __ww_mutex_wakeup_for_backoff+0xf0/0xf0
[   92.782480]  ? seg6_build_state+0x11d/0x240
[   92.782925]  ? lwtunnel_build_state+0x1bd/0x210
[   92.783393]  ? ip6_route_info_create+0x687/0x1640
[   92.783846]  ? ip6_route_add+0x74/0x110
[   92.784236]  ? inet6_rtm_newroute+0x8a/0xd0

Fixes: 6c8702c ("ipv6: sr: add support for SRH encapsulation and injection with lwtunnels")
Signed-off-by: David Lebrun <dlebrun@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
anthraxx referenced this issue in anthraxx/linux-hardened Apr 24, 2018
Scheduler debug stats include newlines that display out of alignment
when prefixed by timestamps.  For example, the dmesg utility:

  % echo t > /proc/sysrq-trigger
  % dmesg
  ...
  [   83.124251]
  runnable tasks:
   S           task   PID         tree-key  switches  prio     wait-time
  sum-exec        sum-sleep
  -----------------------------------------------------------------------------------------------------------

At the same time, some syslog utilities (like rsyslog by default) don't
like the additional newlines control characters, saving lines like this
to /var/log/messages:

  Mar 16 16:02:29 localhost kernel: #012runnable tasks:#12 S           task   PID         tree-key ...
                                    ^^^^               ^^^^
Clean these up by moving newline characters to their own SEQ_printf
invocation.  This leaves the /proc/sched_debug unchanged, but brings the
entire output into alignment when prefixed:

  % echo t > /proc/sysrq-trigger
  % dmesg
  ...
  [   62.410368] runnable tasks:
  [   62.410368]  S           task   PID         tree-key  switches  prio     wait-time             sum-exec        sum-sleep
  [   62.410369] -----------------------------------------------------------------------------------------------------------
  [   62.410369]  I  kworker/u12:0     5      1932.215593       332   120         0.000000         3.621252         0.000000 0 0 /

and no escaped control characters from rsyslog in /var/log/messages:

  Mar 16 16:15:06 localhost kernel: runnable tasks:
  Mar 16 16:15:06 localhost kernel: S           task   PID         tree-key  ...

Signed-off-by: Joe Lawrence <joe.lawrence@redhat.com>
Acked-by: Peter Zijlstra <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1521484555-8620-3-git-send-email-joe.lawrence@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
anthraxx referenced this issue in anthraxx/linux-hardened Apr 24, 2018
The seg6_build_state() function is called with RCU read lock held,
so we cannot use GFP_KERNEL. This patch uses GFP_ATOMIC instead.

[   92.770271] =============================
[   92.770628] WARNING: suspicious RCU usage
[   92.770921] 4.16.0-rc4+ #12 Not tainted
[   92.771277] -----------------------------
[   92.771585] ./include/linux/rcupdate.h:302 Illegal context switch in RCU read-side critical section!
[   92.772279]
[   92.772279] other info that might help us debug this:
[   92.772279]
[   92.773067]
[   92.773067] rcu_scheduler_active = 2, debug_locks = 1
[   92.773514] 2 locks held by ip/2413:
[   92.773765]  #0:  (rtnl_mutex){+.+.}, at: [<00000000e5461720>] rtnetlink_rcv_msg+0x441/0x4d0
[   92.774377]  #1:  (rcu_read_lock){....}, at: [<00000000df4f161e>] lwtunnel_build_state+0x59/0x210
[   92.775065]
[   92.775065] stack backtrace:
[   92.775371] CPU: 0 PID: 2413 Comm: ip Not tainted 4.16.0-rc4+ #12
[   92.775791] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.2-1.fc27 04/01/2014
[   92.776608] Call Trace:
[   92.776852]  dump_stack+0x7d/0xbc
[   92.777130]  __schedule+0x133/0xf00
[   92.777393]  ? unwind_get_return_address_ptr+0x50/0x50
[   92.777783]  ? __sched_text_start+0x8/0x8
[   92.778073]  ? rcu_is_watching+0x19/0x30
[   92.778383]  ? kernel_text_address+0x49/0x60
[   92.778800]  ? __kernel_text_address+0x9/0x30
[   92.779241]  ? unwind_get_return_address+0x29/0x40
[   92.779727]  ? pcpu_alloc+0x102/0x8f0
[   92.780101]  _cond_resched+0x23/0x50
[   92.780459]  __mutex_lock+0xbd/0xad0
[   92.780818]  ? pcpu_alloc+0x102/0x8f0
[   92.781194]  ? seg6_build_state+0x11d/0x240
[   92.781611]  ? save_stack+0x9b/0xb0
[   92.781965]  ? __ww_mutex_wakeup_for_backoff+0xf0/0xf0
[   92.782480]  ? seg6_build_state+0x11d/0x240
[   92.782925]  ? lwtunnel_build_state+0x1bd/0x210
[   92.783393]  ? ip6_route_info_create+0x687/0x1640
[   92.783846]  ? ip6_route_add+0x74/0x110
[   92.784236]  ? inet6_rtm_newroute+0x8a/0xd0

Fixes: 6c8702c ("ipv6: sr: add support for SRH encapsulation and injection with lwtunnels")
Signed-off-by: David Lebrun <dlebrun@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
d1b pushed a commit to d1b/linux-hardened that referenced this issue Apr 25, 2018
…ns[]

When adding GP-1-28 port pin support it was forgotten to remove the
CLKOUT pin from the list of pins that are not associated with a GPIO
port in pinmux_pins[]. This results in a warning when reading the
pinctrl files in sysfs as the CLKOUT pin is still added as a none GPIO
pin. Fix this by removing the duplicated entry which is no longer
needed.

~ # cat /sys/kernel/debug/pinctrl/e6060000.pin-controller/pinconf-pins
[   89.432081] ------------[ cut here ]------------
[   89.436904] Pin 496 is not in bias info list
[   89.441252] WARNING: CPU: 1 PID: 456 at drivers/pinctrl/sh-pfc/core.c:408 sh_pfc_pin_to_bias_reg+0xb0/0xb8
[   89.451002] CPU: 1 PID: 456 Comm: cat Not tainted 4.16.0-rc1-arm64-renesas-00048-gdfafc344a4f24dde GrapheneOS#12
[   89.460394] Hardware name: Renesas Salvator-X 2nd version board based on r8a7795 ES2.0+ (DT)
[   89.468910] pstate: 80000085 (Nzcv daIf -PAN -UAO)
[   89.473747] pc : sh_pfc_pin_to_bias_reg+0xb0/0xb8
[   89.478495] lr : sh_pfc_pin_to_bias_reg+0xb0/0xb8
[   89.483241] sp : ffff00000aff3ab0
[   89.486587] x29: ffff00000aff3ab0 x28: ffff00000893c698
[   89.491955] x27: ffff000008ad7d98 x26: 0000000000000000
[   89.497323] x25: ffff8006fb3f5028 x24: ffff8006fb3f5018
[   89.502690] x23: 0000000000000001 x22: 00000000000001f0
[   89.508057] x21: ffff8006fb3f5018 x20: ffff000008bef000
[   89.513423] x19: 0000000000000000 x18: ffffffffffffffff
[   89.518790] x17: 0000000000006c4a x16: ffff000008d67c98
[   89.524157] x15: 0000000000000001 x14: ffff00000896ca98
[   89.529524] x13: 00000000cce5f611 x12: ffff8006f8d3b5a8
[   89.534891] x11: ffff00000981e000 x10: ffff000008befa08
[   89.540258] x9 : ffff8006f9b987a0 x8 : ffff000008befa08
[   89.545625] x7 : ffff000008137094 x6 : 0000000000000000
[   89.550991] x5 : 0000000000000000 x4 : 0000000000000001
[   89.556357] x3 : 0000000000000007 x2 : 0000000000000007
[   89.561723] x1 : 1ff24f80f1818600 x0 : 0000000000000000
[   89.567091] Call trace:
[   89.569561]  sh_pfc_pin_to_bias_reg+0xb0/0xb8
[   89.573960]  r8a7795_pinmux_get_bias+0x30/0xc0
[   89.578445]  sh_pfc_pinconf_get+0x1e0/0x2d8
[   89.582669]  pin_config_get_for_pin+0x20/0x30
[   89.587067]  pinconf_generic_dump_one+0x180/0x1c8
[   89.591815]  pinconf_generic_dump_pins+0x84/0xd8
[   89.596476]  pinconf_pins_show+0xc8/0x130
[   89.600528]  seq_read+0xe4/0x510
[   89.603789]  full_proxy_read+0x60/0x90
[   89.607576]  __vfs_read+0x30/0x140
[   89.611010]  vfs_read+0x90/0x170
[   89.614269]  SyS_read+0x60/0xd8
[   89.617443]  __sys_trace_return+0x0/0x4
[   89.621314] ---[ end trace 99c8d0d39c13e794 ]---

Fixes: 82d2de5 ("pinctrl: sh-pfc: r8a7795: Add GP-1-28 port pin support")
Reviewed-and-tested-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
thestinger pushed a commit that referenced this issue May 21, 2018
[ Upstream commit af50e4b ]

syzbot caught an infinite recursion in nsh_gso_segment().

Problem here is that we need to make sure the NSH header is of
reasonable length.

BUG: MAX_LOCK_DEPTH too low!
turning off the locking correctness validator.
depth: 48  max: 48!
48 locks held by syz-executor0/10189:
 #0:         (ptrval) (rcu_read_lock_bh){....}, at: __dev_queue_xmit+0x30f/0x34c0 net/core/dev.c:3517
 #1:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #1:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #2:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #2:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #3:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #3:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #4:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #4:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #5:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #5:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #6:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #6:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #7:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #7:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #8:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #8:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #9:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #9:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #10:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #10:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #11:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #11:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #12:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #12:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #13:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #13:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #14:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #14:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #15:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #15:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #16:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #16:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #17:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #17:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #18:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #18:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #19:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #19:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #20:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #20:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #21:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #21:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #22:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #22:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #23:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #23:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #24:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #24:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #25:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #25:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #26:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #26:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #27:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #27:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #28:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #28:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #29:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #29:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #30:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #30:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #31:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #31:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
dccp_close: ABORT with 65423 bytes unread
 #32:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #32:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #33:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #33:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #34:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #34:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #35:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #35:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #36:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #36:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #37:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #37:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #38:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #38:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #39:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #39:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #40:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #40:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #41:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #41:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #42:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #42:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #43:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #43:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #44:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #44:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #45:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #45:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #46:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #46:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #47:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #47:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
INFO: lockdep is turned off.
CPU: 1 PID: 10189 Comm: syz-executor0 Not tainted 4.17.0-rc2+ #26
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x1b9/0x294 lib/dump_stack.c:113
 __lock_acquire+0x1788/0x5140 kernel/locking/lockdep.c:3449
 lock_acquire+0x1dc/0x520 kernel/locking/lockdep.c:3920
 rcu_lock_acquire include/linux/rcupdate.h:246 [inline]
 rcu_read_lock include/linux/rcupdate.h:632 [inline]
 skb_mac_gso_segment+0x25b/0x720 net/core/dev.c:2789
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 __skb_gso_segment+0x3bb/0x870 net/core/dev.c:2865
 skb_gso_segment include/linux/netdevice.h:4025 [inline]
 validate_xmit_skb+0x54d/0xd90 net/core/dev.c:3118
 validate_xmit_skb_list+0xbf/0x120 net/core/dev.c:3168
 sch_direct_xmit+0x354/0x11e0 net/sched/sch_generic.c:312
 qdisc_restart net/sched/sch_generic.c:399 [inline]
 __qdisc_run+0x741/0x1af0 net/sched/sch_generic.c:410
 __dev_xmit_skb net/core/dev.c:3243 [inline]
 __dev_queue_xmit+0x28ea/0x34c0 net/core/dev.c:3551
 dev_queue_xmit+0x17/0x20 net/core/dev.c:3616
 packet_snd net/packet/af_packet.c:2951 [inline]
 packet_sendmsg+0x40f8/0x6070 net/packet/af_packet.c:2976
 sock_sendmsg_nosec net/socket.c:629 [inline]
 sock_sendmsg+0xd5/0x120 net/socket.c:639
 __sys_sendto+0x3d7/0x670 net/socket.c:1789
 __do_sys_sendto net/socket.c:1801 [inline]
 __se_sys_sendto net/socket.c:1797 [inline]
 __x64_sys_sendto+0xe1/0x1a0 net/socket.c:1797
 do_syscall_64+0x1b1/0x800 arch/x86/entry/common.c:287
 entry_SYSCALL_64_after_hwframe+0x49/0xbe

Fixes: c411ed8 ("nsh: add GSO support")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Jiri Benc <jbenc@redhat.com>
Reported-by: syzbot <syzkaller@googlegroups.com>
Acked-by: Jiri Benc <jbenc@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
anthraxx referenced this issue in anthraxx/linux-hardened May 22, 2018
[ Upstream commit af50e4b ]

syzbot caught an infinite recursion in nsh_gso_segment().

Problem here is that we need to make sure the NSH header is of
reasonable length.

BUG: MAX_LOCK_DEPTH too low!
turning off the locking correctness validator.
depth: 48  max: 48!
48 locks held by syz-executor0/10189:
 #0:         (ptrval) (rcu_read_lock_bh){....}, at: __dev_queue_xmit+0x30f/0x34c0 net/core/dev.c:3517
 #1:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #1:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #2:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #2:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #3:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #3:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #4:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #4:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #5:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #5:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #6:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #6:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #7:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #7:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #8:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #8:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #9:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #9:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #10:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #10:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #11:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #11:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #12:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #12:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #13:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #13:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #14:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #14:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #15:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #15:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #16:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #16:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #17:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #17:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #18:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #18:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #19:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #19:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #20:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #20:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #21:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #21:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #22:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #22:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #23:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #23:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #24:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #24:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #25:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #25:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #26:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #26:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #27:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #27:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #28:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #28:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #29:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #29:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #30:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #30:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #31:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #31:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
dccp_close: ABORT with 65423 bytes unread
 #32:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #32:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #33:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #33:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #34:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #34:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #35:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #35:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #36:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #36:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #37:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #37:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #38:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #38:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #39:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #39:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #40:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #40:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #41:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #41:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #42:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #42:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #43:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #43:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #44:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #44:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #45:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #45:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #46:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #46:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #47:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #47:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
INFO: lockdep is turned off.
CPU: 1 PID: 10189 Comm: syz-executor0 Not tainted 4.17.0-rc2+ #26
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x1b9/0x294 lib/dump_stack.c:113
 __lock_acquire+0x1788/0x5140 kernel/locking/lockdep.c:3449
 lock_acquire+0x1dc/0x520 kernel/locking/lockdep.c:3920
 rcu_lock_acquire include/linux/rcupdate.h:246 [inline]
 rcu_read_lock include/linux/rcupdate.h:632 [inline]
 skb_mac_gso_segment+0x25b/0x720 net/core/dev.c:2789
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 __skb_gso_segment+0x3bb/0x870 net/core/dev.c:2865
 skb_gso_segment include/linux/netdevice.h:4025 [inline]
 validate_xmit_skb+0x54d/0xd90 net/core/dev.c:3118
 validate_xmit_skb_list+0xbf/0x120 net/core/dev.c:3168
 sch_direct_xmit+0x354/0x11e0 net/sched/sch_generic.c:312
 qdisc_restart net/sched/sch_generic.c:399 [inline]
 __qdisc_run+0x741/0x1af0 net/sched/sch_generic.c:410
 __dev_xmit_skb net/core/dev.c:3243 [inline]
 __dev_queue_xmit+0x28ea/0x34c0 net/core/dev.c:3551
 dev_queue_xmit+0x17/0x20 net/core/dev.c:3616
 packet_snd net/packet/af_packet.c:2951 [inline]
 packet_sendmsg+0x40f8/0x6070 net/packet/af_packet.c:2976
 sock_sendmsg_nosec net/socket.c:629 [inline]
 sock_sendmsg+0xd5/0x120 net/socket.c:639
 __sys_sendto+0x3d7/0x670 net/socket.c:1789
 __do_sys_sendto net/socket.c:1801 [inline]
 __se_sys_sendto net/socket.c:1797 [inline]
 __x64_sys_sendto+0xe1/0x1a0 net/socket.c:1797
 do_syscall_64+0x1b1/0x800 arch/x86/entry/common.c:287
 entry_SYSCALL_64_after_hwframe+0x49/0xbe

Fixes: c411ed8 ("nsh: add GSO support")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Jiri Benc <jbenc@redhat.com>
Reported-by: syzbot <syzkaller@googlegroups.com>
Acked-by: Jiri Benc <jbenc@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
anthraxx referenced this issue in anthraxx/linux-hardened May 31, 2018
[ Upstream commit fca3234 ]

Executing command 'perf stat -T -- ls' dumps core on x86 and s390.

Here is the call back chain (done on x86):

 # gdb ./perf
 ....
 (gdb) r stat -T -- ls
...
Program received signal SIGSEGV, Segmentation fault.
0x00007ffff56d1963 in vasprintf () from /lib64/libc.so.6
(gdb) where
 #0  0x00007ffff56d1963 in vasprintf () from /lib64/libc.so.6
 #1  0x00007ffff56ae484 in asprintf () from /lib64/libc.so.6
 #2  0x00000000004f1982 in __parse_events_add_pmu (parse_state=0x7fffffffd580,
    list=0xbfb970, name=0xbf3ef0 "cpu",
    head_config=0xbfb930, auto_merge_stats=false) at util/parse-events.c:1233
 #3  0x00000000004f1c8e in parse_events_add_pmu (parse_state=0x7fffffffd580,
    list=0xbfb970, name=0xbf3ef0 "cpu",
    head_config=0xbfb930) at util/parse-events.c:1288
 #4  0x0000000000537ce3 in parse_events_parse (_parse_state=0x7fffffffd580,
    scanner=0xbf4210) at util/parse-events.y:234
 #5  0x00000000004f2c7a in parse_events__scanner (str=0x6b66c0
    "task-clock,{instructions,cycles,cpu/cycles-t/,cpu/tx-start/}",
    parse_state=0x7fffffffd580, start_token=258) at util/parse-events.c:1673
 #6  0x00000000004f2e23 in parse_events (evlist=0xbe9990, str=0x6b66c0
    "task-clock,{instructions,cycles,cpu/cycles-t/,cpu/tx-start/}", err=0x0)
    at util/parse-events.c:1713
 #7  0x000000000044e137 in add_default_attributes () at builtin-stat.c:2281
 #8  0x000000000044f7b5 in cmd_stat (argc=1, argv=0x7fffffffe3b0) at
    builtin-stat.c:2828
 #9  0x00000000004c8b0f in run_builtin (p=0xab01a0 <commands+288>, argc=4,
    argv=0x7fffffffe3b0) at perf.c:297
 #10 0x00000000004c8d7c in handle_internal_command (argc=4,
    argv=0x7fffffffe3b0) at perf.c:349
 #11 0x00000000004c8ece in run_argv (argcp=0x7fffffffe20c,
   argv=0x7fffffffe200) at perf.c:393
 #12 0x00000000004c929c in main (argc=4, argv=0x7fffffffe3b0) at perf.c:537
(gdb)

It turns out that a NULL pointer is referenced. Here are the
function calls:

  ...
  cmd_stat()
  +---> add_default_attributes()
	+---> parse_events(evsel_list, transaction_attrs, NULL);
	             3rd parameter set to NULL

Function parse_events(xx, xx, struct parse_events_error *err) dives
into a bison generated scanner and creates
parser state information for it first:

   struct parse_events_state parse_state = {
                .list   = LIST_HEAD_INIT(parse_state.list),
                .idx    = evlist->nr_entries,
                .error  = err,   <--- NULL POINTER !!!
                .evlist = evlist,
        };

Now various functions inside the bison scanner are called to end up in
__parse_events_add_pmu(struct parse_events_state *parse_state, ..) with
first parameter being a pointer to above structure definition.

Now the PMU event name is not found (because being executed in a VM) and
this function tries to create an error message with

   asprintf(&parse_state->error.str, ....)

which references a NULL pointer and dumps core.

Fix this by providing a pointer to the necessary error information
instead of NULL. Technically only the else part is needed to avoid the
core dump, just lets be safe...

Signed-off-by: Thomas Richter <tmricht@linux.vnet.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Hendrik Brueckner <brueckner@linux.vnet.ibm.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Link: http://lkml.kernel.org/r/20180308145735.64717-1-tmricht@linux.vnet.ibm.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
anthraxx referenced this issue in anthraxx/linux-hardened May 31, 2018
[ Upstream commit 2bbea6e ]

when mounting an ISO filesystem sometimes (very rarely)
the system hangs because of a race condition between two tasks.

PID: 6766   TASK: ffff88007b2a6dd0  CPU: 0   COMMAND: "mount"
 #0 [ffff880078447ae0] __schedule at ffffffff8168d605
 #1 [ffff880078447b48] schedule_preempt_disabled at ffffffff8168ed49
 #2 [ffff880078447b58] __mutex_lock_slowpath at ffffffff8168c995
 #3 [ffff880078447bb8] mutex_lock at ffffffff8168bdef
 #4 [ffff880078447bd0] sr_block_ioctl at ffffffffa00b6818 [sr_mod]
 #5 [ffff880078447c10] blkdev_ioctl at ffffffff812fea50
 #6 [ffff880078447c70] ioctl_by_bdev at ffffffff8123a8b3
 #7 [ffff880078447c90] isofs_fill_super at ffffffffa04fb1e1 [isofs]
 #8 [ffff880078447da8] mount_bdev at ffffffff81202570
 #9 [ffff880078447e18] isofs_mount at ffffffffa04f9828 [isofs]
#10 [ffff880078447e28] mount_fs at ffffffff81202d09
#11 [ffff880078447e70] vfs_kern_mount at ffffffff8121ea8f
#12 [ffff880078447ea8] do_mount at ffffffff81220fee
#13 [ffff880078447f28] sys_mount at ffffffff812218d6
#14 [ffff880078447f80] system_call_fastpath at ffffffff81698c49
    RIP: 00007fd9ea914e9a  RSP: 00007ffd5d9bf648  RFLAGS: 00010246
    RAX: 00000000000000a5  RBX: ffffffff81698c49  RCX: 0000000000000010
    RDX: 00007fd9ec2bc210  RSI: 00007fd9ec2bc290  RDI: 00007fd9ec2bcf30
    RBP: 0000000000000000   R8: 0000000000000000   R9: 0000000000000010
    R10: 00000000c0ed0001  R11: 0000000000000206  R12: 00007fd9ec2bc040
    R13: 00007fd9eb6b2380  R14: 00007fd9ec2bc210  R15: 00007fd9ec2bcf30
    ORIG_RAX: 00000000000000a5  CS: 0033  SS: 002b

This task was trying to mount the cdrom.  It allocated and configured a
super_block struct and owned the write-lock for the super_block->s_umount
rwsem. While exclusively owning the s_umount lock, it called
sr_block_ioctl and waited to acquire the global sr_mutex lock.

PID: 6785   TASK: ffff880078720fb0  CPU: 0   COMMAND: "systemd-udevd"
 #0 [ffff880078417898] __schedule at ffffffff8168d605
 #1 [ffff880078417900] schedule at ffffffff8168dc59
 #2 [ffff880078417910] rwsem_down_read_failed at ffffffff8168f605
 #3 [ffff880078417980] call_rwsem_down_read_failed at ffffffff81328838
 #4 [ffff8800784179d0] down_read at ffffffff8168cde0
 #5 [ffff8800784179e8] get_super at ffffffff81201cc7
 #6 [ffff880078417a10] __invalidate_device at ffffffff8123a8de
 #7 [ffff880078417a40] flush_disk at ffffffff8123a94b
 #8 [ffff880078417a88] check_disk_change at ffffffff8123ab50
 #9 [ffff880078417ab0] cdrom_open at ffffffffa00a29e1 [cdrom]
#10 [ffff880078417b68] sr_block_open at ffffffffa00b6f9b [sr_mod]
#11 [ffff880078417b98] __blkdev_get at ffffffff8123ba86
#12 [ffff880078417bf0] blkdev_get at ffffffff8123bd65
#13 [ffff880078417c78] blkdev_open at ffffffff8123bf9b
#14 [ffff880078417c90] do_dentry_open at ffffffff811fc7f7
#15 [ffff880078417cd8] vfs_open at ffffffff811fc9cf
#16 [ffff880078417d00] do_last at ffffffff8120d53d
#17 [ffff880078417db0] path_openat at ffffffff8120e6b2
#18 [ffff880078417e48] do_filp_open at ffffffff8121082b
#19 [ffff880078417f18] do_sys_open at ffffffff811fdd33
#20 [ffff880078417f70] sys_open at ffffffff811fde4e
#21 [ffff880078417f80] system_call_fastpath at ffffffff81698c49
    RIP: 00007f29438b0c20  RSP: 00007ffc76624b78  RFLAGS: 00010246
    RAX: 0000000000000002  RBX: ffffffff81698c49  RCX: 0000000000000000
    RDX: 00007f2944a5fa70  RSI: 00000000000a0800  RDI: 00007f2944a5fa70
    RBP: 00007f2944a5f540   R8: 0000000000000000   R9: 0000000000000020
    R10: 00007f2943614c40  R11: 0000000000000246  R12: ffffffff811fde4e
    R13: ffff880078417f78  R14: 000000000000000c  R15: 00007f2944a4b010
    ORIG_RAX: 0000000000000002  CS: 0033  SS: 002b

This task tried to open the cdrom device, the sr_block_open function
acquired the global sr_mutex lock. The call to check_disk_change()
then saw an event flag indicating a possible media change and tried
to flush any cached data for the device.
As part of the flush, it tried to acquire the super_block->s_umount
lock associated with the cdrom device.
This was the same super_block as created and locked by the previous task.

The first task acquires the s_umount lock and then the sr_mutex_lock;
the second task acquires the sr_mutex_lock and then the s_umount lock.

This patch fixes the issue by moving check_disk_change() out of
cdrom_open() and let the caller take care of it.

Signed-off-by: Maurizio Lombardi <mlombard@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
anthraxx referenced this issue in anthraxx/linux-hardened May 31, 2018
[ Upstream commit fca3234 ]

Executing command 'perf stat -T -- ls' dumps core on x86 and s390.

Here is the call back chain (done on x86):

 # gdb ./perf
 ....
 (gdb) r stat -T -- ls
...
Program received signal SIGSEGV, Segmentation fault.
0x00007ffff56d1963 in vasprintf () from /lib64/libc.so.6
(gdb) where
 #0  0x00007ffff56d1963 in vasprintf () from /lib64/libc.so.6
 #1  0x00007ffff56ae484 in asprintf () from /lib64/libc.so.6
 #2  0x00000000004f1982 in __parse_events_add_pmu (parse_state=0x7fffffffd580,
    list=0xbfb970, name=0xbf3ef0 "cpu",
    head_config=0xbfb930, auto_merge_stats=false) at util/parse-events.c:1233
 #3  0x00000000004f1c8e in parse_events_add_pmu (parse_state=0x7fffffffd580,
    list=0xbfb970, name=0xbf3ef0 "cpu",
    head_config=0xbfb930) at util/parse-events.c:1288
 #4  0x0000000000537ce3 in parse_events_parse (_parse_state=0x7fffffffd580,
    scanner=0xbf4210) at util/parse-events.y:234
 #5  0x00000000004f2c7a in parse_events__scanner (str=0x6b66c0
    "task-clock,{instructions,cycles,cpu/cycles-t/,cpu/tx-start/}",
    parse_state=0x7fffffffd580, start_token=258) at util/parse-events.c:1673
 #6  0x00000000004f2e23 in parse_events (evlist=0xbe9990, str=0x6b66c0
    "task-clock,{instructions,cycles,cpu/cycles-t/,cpu/tx-start/}", err=0x0)
    at util/parse-events.c:1713
 #7  0x000000000044e137 in add_default_attributes () at builtin-stat.c:2281
 #8  0x000000000044f7b5 in cmd_stat (argc=1, argv=0x7fffffffe3b0) at
    builtin-stat.c:2828
 #9  0x00000000004c8b0f in run_builtin (p=0xab01a0 <commands+288>, argc=4,
    argv=0x7fffffffe3b0) at perf.c:297
 #10 0x00000000004c8d7c in handle_internal_command (argc=4,
    argv=0x7fffffffe3b0) at perf.c:349
 #11 0x00000000004c8ece in run_argv (argcp=0x7fffffffe20c,
   argv=0x7fffffffe200) at perf.c:393
 #12 0x00000000004c929c in main (argc=4, argv=0x7fffffffe3b0) at perf.c:537
(gdb)

It turns out that a NULL pointer is referenced. Here are the
function calls:

  ...
  cmd_stat()
  +---> add_default_attributes()
	+---> parse_events(evsel_list, transaction_attrs, NULL);
	             3rd parameter set to NULL

Function parse_events(xx, xx, struct parse_events_error *err) dives
into a bison generated scanner and creates
parser state information for it first:

   struct parse_events_state parse_state = {
                .list   = LIST_HEAD_INIT(parse_state.list),
                .idx    = evlist->nr_entries,
                .error  = err,   <--- NULL POINTER !!!
                .evlist = evlist,
        };

Now various functions inside the bison scanner are called to end up in
__parse_events_add_pmu(struct parse_events_state *parse_state, ..) with
first parameter being a pointer to above structure definition.

Now the PMU event name is not found (because being executed in a VM) and
this function tries to create an error message with

   asprintf(&parse_state->error.str, ....)

which references a NULL pointer and dumps core.

Fix this by providing a pointer to the necessary error information
instead of NULL. Technically only the else part is needed to avoid the
core dump, just lets be safe...

Signed-off-by: Thomas Richter <tmricht@linux.vnet.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Hendrik Brueckner <brueckner@linux.vnet.ibm.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Link: http://lkml.kernel.org/r/20180308145735.64717-1-tmricht@linux.vnet.ibm.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
anthraxx referenced this issue in anthraxx/linux-hardened May 31, 2018
[ Upstream commit 2bbea6e ]

when mounting an ISO filesystem sometimes (very rarely)
the system hangs because of a race condition between two tasks.

PID: 6766   TASK: ffff88007b2a6dd0  CPU: 0   COMMAND: "mount"
 #0 [ffff880078447ae0] __schedule at ffffffff8168d605
 #1 [ffff880078447b48] schedule_preempt_disabled at ffffffff8168ed49
 #2 [ffff880078447b58] __mutex_lock_slowpath at ffffffff8168c995
 #3 [ffff880078447bb8] mutex_lock at ffffffff8168bdef
 #4 [ffff880078447bd0] sr_block_ioctl at ffffffffa00b6818 [sr_mod]
 #5 [ffff880078447c10] blkdev_ioctl at ffffffff812fea50
 #6 [ffff880078447c70] ioctl_by_bdev at ffffffff8123a8b3
 #7 [ffff880078447c90] isofs_fill_super at ffffffffa04fb1e1 [isofs]
 #8 [ffff880078447da8] mount_bdev at ffffffff81202570
 #9 [ffff880078447e18] isofs_mount at ffffffffa04f9828 [isofs]
#10 [ffff880078447e28] mount_fs at ffffffff81202d09
#11 [ffff880078447e70] vfs_kern_mount at ffffffff8121ea8f
#12 [ffff880078447ea8] do_mount at ffffffff81220fee
#13 [ffff880078447f28] sys_mount at ffffffff812218d6
#14 [ffff880078447f80] system_call_fastpath at ffffffff81698c49
    RIP: 00007fd9ea914e9a  RSP: 00007ffd5d9bf648  RFLAGS: 00010246
    RAX: 00000000000000a5  RBX: ffffffff81698c49  RCX: 0000000000000010
    RDX: 00007fd9ec2bc210  RSI: 00007fd9ec2bc290  RDI: 00007fd9ec2bcf30
    RBP: 0000000000000000   R8: 0000000000000000   R9: 0000000000000010
    R10: 00000000c0ed0001  R11: 0000000000000206  R12: 00007fd9ec2bc040
    R13: 00007fd9eb6b2380  R14: 00007fd9ec2bc210  R15: 00007fd9ec2bcf30
    ORIG_RAX: 00000000000000a5  CS: 0033  SS: 002b

This task was trying to mount the cdrom.  It allocated and configured a
super_block struct and owned the write-lock for the super_block->s_umount
rwsem. While exclusively owning the s_umount lock, it called
sr_block_ioctl and waited to acquire the global sr_mutex lock.

PID: 6785   TASK: ffff880078720fb0  CPU: 0   COMMAND: "systemd-udevd"
 #0 [ffff880078417898] __schedule at ffffffff8168d605
 #1 [ffff880078417900] schedule at ffffffff8168dc59
 #2 [ffff880078417910] rwsem_down_read_failed at ffffffff8168f605
 #3 [ffff880078417980] call_rwsem_down_read_failed at ffffffff81328838
 #4 [ffff8800784179d0] down_read at ffffffff8168cde0
 #5 [ffff8800784179e8] get_super at ffffffff81201cc7
 #6 [ffff880078417a10] __invalidate_device at ffffffff8123a8de
 #7 [ffff880078417a40] flush_disk at ffffffff8123a94b
 #8 [ffff880078417a88] check_disk_change at ffffffff8123ab50
 #9 [ffff880078417ab0] cdrom_open at ffffffffa00a29e1 [cdrom]
#10 [ffff880078417b68] sr_block_open at ffffffffa00b6f9b [sr_mod]
#11 [ffff880078417b98] __blkdev_get at ffffffff8123ba86
#12 [ffff880078417bf0] blkdev_get at ffffffff8123bd65
#13 [ffff880078417c78] blkdev_open at ffffffff8123bf9b
#14 [ffff880078417c90] do_dentry_open at ffffffff811fc7f7
#15 [ffff880078417cd8] vfs_open at ffffffff811fc9cf
#16 [ffff880078417d00] do_last at ffffffff8120d53d
#17 [ffff880078417db0] path_openat at ffffffff8120e6b2
#18 [ffff880078417e48] do_filp_open at ffffffff8121082b
#19 [ffff880078417f18] do_sys_open at ffffffff811fdd33
#20 [ffff880078417f70] sys_open at ffffffff811fde4e
#21 [ffff880078417f80] system_call_fastpath at ffffffff81698c49
    RIP: 00007f29438b0c20  RSP: 00007ffc76624b78  RFLAGS: 00010246
    RAX: 0000000000000002  RBX: ffffffff81698c49  RCX: 0000000000000000
    RDX: 00007f2944a5fa70  RSI: 00000000000a0800  RDI: 00007f2944a5fa70
    RBP: 00007f2944a5f540   R8: 0000000000000000   R9: 0000000000000020
    R10: 00007f2943614c40  R11: 0000000000000246  R12: ffffffff811fde4e
    R13: ffff880078417f78  R14: 000000000000000c  R15: 00007f2944a4b010
    ORIG_RAX: 0000000000000002  CS: 0033  SS: 002b

This task tried to open the cdrom device, the sr_block_open function
acquired the global sr_mutex lock. The call to check_disk_change()
then saw an event flag indicating a possible media change and tried
to flush any cached data for the device.
As part of the flush, it tried to acquire the super_block->s_umount
lock associated with the cdrom device.
This was the same super_block as created and locked by the previous task.

The first task acquires the s_umount lock and then the sr_mutex_lock;
the second task acquires the sr_mutex_lock and then the s_umount lock.

This patch fixes the issue by moving check_disk_change() out of
cdrom_open() and let the caller take care of it.

Signed-off-by: Maurizio Lombardi <mlombard@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
anthraxx referenced this issue in anthraxx/linux-hardened Jul 4, 2018
…sion

commit 8afb1d2 upstream.

Commit 40f70c0 ("serial: sh-sci: add locking to console write
function to avoid SMP lockup") copied the strategy to avoid locking
problems in conjuncture with the console from the UART8250
driver. Instead using directly spin_{try}lock_irqsave(),
local_irq_save() followed by spin_{try}lock() was used. While this is
correct on mainline, for -rt it is a problem. spin_{try}lock() will
check if it is running in a valid context. Since the local_irq_save()
has already been executed, the context has changed and
spin_{try}lock() will complain. The reason why spin_{try}lock()
complains is that on -rt the spin locks are turned into mutexes and
therefore can sleep. Sleeping with interrupts disabled is not valid.

BUG: sleeping function called from invalid context at /home/wagi/work/rt/v4.4-cip-rt/kernel/locking/rtmutex.c:995
in_atomic(): 0, irqs_disabled(): 128, pid: 778, name: irq/76-eth0
CPU: 0 PID: 778 Comm: irq/76-eth0 Not tainted 4.4.126-test-cip22-rt14-00403-gcd03665c8318 #12
Hardware name: Generic RZ/G1 (Flattened Device Tree)
Backtrace:
[<c00140a0>] (dump_backtrace) from [<c001424c>] (show_stack+0x18/0x1c)
 r7:c06b01f0 r6:60010193 r5:00000000 r4:c06b01f0
[<c0014234>] (show_stack) from [<c01d3c94>] (dump_stack+0x78/0x94)
[<c01d3c1c>] (dump_stack) from [<c004c134>] (___might_sleep+0x134/0x194)
 r7:60010113 r6:c06d3559 r5:00000000 r4:ffffe000
[<c004c000>] (___might_sleep) from [<c04ded60>] (rt_spin_lock+0x20/0x74)
 r5:c06f4d60 r4:c06f4d60
[<c04ded40>] (rt_spin_lock) from [<c02577e4>] (serial_console_write+0x100/0x118)
 r5:c06f4d60 r4:c06f4d60
[<c02576e4>] (serial_console_write) from [<c0061060>] (call_console_drivers.constprop.15+0x10c/0x124)
 r10:c06d2894 r9:c04e18b0 r8:00000028 r7:00000000 r6:c06d3559 r5:c06d2798
 r4:c06b9914 r3:c02576e4
[<c0060f54>] (call_console_drivers.constprop.15) from [<c0062984>] (console_unlock+0x32c/0x430)
 r10:c06d30d8 r9:00000028 r8:c06dd518 r7:00000005 r6:00000000 r5:c06d2798
 r4:c06d2798 r3:00000028
[<c0062658>] (console_unlock) from [<c0062e1c>] (vprintk_emit+0x394/0x4f0)
 r10:c06d2798 r9:c06d30ee r8:00000006 r7:00000005 r6:c06a78fc r5:00000027
 r4:00000003
[<c0062a88>] (vprintk_emit) from [<c0062fa0>] (vprintk+0x28/0x30)
 r10:c060bd46 r9:00001000 r8:c06b9a90 r7:c06b9a90 r6:c06b994c r5:c06b9a3c
 r4:c0062fa8
[<c0062f78>] (vprintk) from [<c0062fb8>] (vprintk_default+0x10/0x14)
[<c0062fa8>] (vprintk_default) from [<c009cd30>] (printk+0x78/0x84)
[<c009ccbc>] (printk) from [<c025afdc>] (credit_entropy_bits+0x17c/0x2cc)
 r3:00000001 r2:decade60 r1:c061a5ee r0:c061a523
 r4:00000006
[<c025ae60>] (credit_entropy_bits) from [<c025bf74>] (add_interrupt_randomness+0x160/0x178)
 r10:466e7196 r9:1f536000 r8:fffeef74 r7:00000000 r6:c06b9a60 r5:c06b9a3c
 r4:dfbcf680
[<c025be14>] (add_interrupt_randomness) from [<c006536c>] (irq_thread+0x1e8/0x248)
 r10:c006537c r9:c06cdf21 r8:c0064fcc r7:df791c24 r6:df791c00 r5:ffffe000
 r4:df525180
[<c0065184>] (irq_thread) from [<c003fba4>] (kthread+0x108/0x11c)
 r10:00000000 r9:00000000 r8:c0065184 r7:df791c00 r6:00000000 r5:df791d00
 r4:decac000
[<c003fa9c>] (kthread) from [<c00101b8>] (ret_from_fork+0x14/0x3c)
 r8:00000000 r7:00000000 r6:00000000 r5:c003fa9c r4:df791d00

Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Daniel Wagner <daniel.wagner@siemens.com>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
anthraxx referenced this issue in anthraxx/linux-hardened Jul 4, 2018
…sion

commit 8afb1d2 upstream.

Commit 40f70c0 ("serial: sh-sci: add locking to console write
function to avoid SMP lockup") copied the strategy to avoid locking
problems in conjuncture with the console from the UART8250
driver. Instead using directly spin_{try}lock_irqsave(),
local_irq_save() followed by spin_{try}lock() was used. While this is
correct on mainline, for -rt it is a problem. spin_{try}lock() will
check if it is running in a valid context. Since the local_irq_save()
has already been executed, the context has changed and
spin_{try}lock() will complain. The reason why spin_{try}lock()
complains is that on -rt the spin locks are turned into mutexes and
therefore can sleep. Sleeping with interrupts disabled is not valid.

BUG: sleeping function called from invalid context at /home/wagi/work/rt/v4.4-cip-rt/kernel/locking/rtmutex.c:995
in_atomic(): 0, irqs_disabled(): 128, pid: 778, name: irq/76-eth0
CPU: 0 PID: 778 Comm: irq/76-eth0 Not tainted 4.4.126-test-cip22-rt14-00403-gcd03665c8318 #12
Hardware name: Generic RZ/G1 (Flattened Device Tree)
Backtrace:
[<c00140a0>] (dump_backtrace) from [<c001424c>] (show_stack+0x18/0x1c)
 r7:c06b01f0 r6:60010193 r5:00000000 r4:c06b01f0
[<c0014234>] (show_stack) from [<c01d3c94>] (dump_stack+0x78/0x94)
[<c01d3c1c>] (dump_stack) from [<c004c134>] (___might_sleep+0x134/0x194)
 r7:60010113 r6:c06d3559 r5:00000000 r4:ffffe000
[<c004c000>] (___might_sleep) from [<c04ded60>] (rt_spin_lock+0x20/0x74)
 r5:c06f4d60 r4:c06f4d60
[<c04ded40>] (rt_spin_lock) from [<c02577e4>] (serial_console_write+0x100/0x118)
 r5:c06f4d60 r4:c06f4d60
[<c02576e4>] (serial_console_write) from [<c0061060>] (call_console_drivers.constprop.15+0x10c/0x124)
 r10:c06d2894 r9:c04e18b0 r8:00000028 r7:00000000 r6:c06d3559 r5:c06d2798
 r4:c06b9914 r3:c02576e4
[<c0060f54>] (call_console_drivers.constprop.15) from [<c0062984>] (console_unlock+0x32c/0x430)
 r10:c06d30d8 r9:00000028 r8:c06dd518 r7:00000005 r6:00000000 r5:c06d2798
 r4:c06d2798 r3:00000028
[<c0062658>] (console_unlock) from [<c0062e1c>] (vprintk_emit+0x394/0x4f0)
 r10:c06d2798 r9:c06d30ee r8:00000006 r7:00000005 r6:c06a78fc r5:00000027
 r4:00000003
[<c0062a88>] (vprintk_emit) from [<c0062fa0>] (vprintk+0x28/0x30)
 r10:c060bd46 r9:00001000 r8:c06b9a90 r7:c06b9a90 r6:c06b994c r5:c06b9a3c
 r4:c0062fa8
[<c0062f78>] (vprintk) from [<c0062fb8>] (vprintk_default+0x10/0x14)
[<c0062fa8>] (vprintk_default) from [<c009cd30>] (printk+0x78/0x84)
[<c009ccbc>] (printk) from [<c025afdc>] (credit_entropy_bits+0x17c/0x2cc)
 r3:00000001 r2:decade60 r1:c061a5ee r0:c061a523
 r4:00000006
[<c025ae60>] (credit_entropy_bits) from [<c025bf74>] (add_interrupt_randomness+0x160/0x178)
 r10:466e7196 r9:1f536000 r8:fffeef74 r7:00000000 r6:c06b9a60 r5:c06b9a3c
 r4:dfbcf680
[<c025be14>] (add_interrupt_randomness) from [<c006536c>] (irq_thread+0x1e8/0x248)
 r10:c006537c r9:c06cdf21 r8:c0064fcc r7:df791c24 r6:df791c00 r5:ffffe000
 r4:df525180
[<c0065184>] (irq_thread) from [<c003fba4>] (kthread+0x108/0x11c)
 r10:00000000 r9:00000000 r8:c0065184 r7:df791c00 r6:00000000 r5:df791d00
 r4:decac000
[<c003fa9c>] (kthread) from [<c00101b8>] (ret_from_fork+0x14/0x3c)
 r8:00000000 r7:00000000 r6:00000000 r5:c003fa9c r4:df791d00

Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Daniel Wagner <daniel.wagner@siemens.com>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
anthraxx referenced this issue in anthraxx/linux-hardened Jul 8, 2018
…s_replace()

commit bbb8c61 upstream.

When a chain is updated, a counter can be attached. if so,
the nft_counters_enabled should be increased.

test commands:

   %nft add table ip filter
   %nft add chain ip filter input { type filter hook input priority 4\; }
   %iptables-compat -Z input
   %nft delete chain ip filter input

we can see below messages.

[  286.443720] jump label: negative count!
[  286.448278] WARNING: CPU: 0 PID: 1459 at kernel/jump_label.c:197 __static_key_slow_dec_cpuslocked+0x6f/0xf0
[  286.449144] Modules linked in: nf_tables nfnetlink ip_tables x_tables
[  286.449144] CPU: 0 PID: 1459 Comm: nft Tainted: G        W         4.17.0-rc2+ #12
[  286.449144] RIP: 0010:__static_key_slow_dec_cpuslocked+0x6f/0xf0
[  286.449144] RSP: 0018:ffff88010e5176f0 EFLAGS: 00010286
[  286.449144] RAX: 000000000000001b RBX: ffffffffc0179500 RCX: ffffffffb8a82522
[  286.449144] RDX: 0000000000000001 RSI: 0000000000000008 RDI: ffff88011b7e5eac
[  286.449144] RBP: 0000000000000000 R08: ffffed00236fce5c R09: ffffed00236fce5b
[  286.449144] R10: ffffffffc0179503 R11: ffffed00236fce5c R12: 0000000000000000
[  286.449144] R13: ffff88011a28e448 R14: ffff88011a28e470 R15: dffffc0000000000
[  286.449144] FS:  00007f0384328700(0000) GS:ffff88011b600000(0000) knlGS:0000000000000000
[  286.449144] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[  286.449144] CR2: 00007f038394bf10 CR3: 0000000104a86000 CR4: 00000000001006f0
[  286.449144] Call Trace:
[  286.449144]  static_key_slow_dec+0x6a/0x70
[  286.449144]  nf_tables_chain_destroy+0x19d/0x210 [nf_tables]
[  286.449144]  nf_tables_commit+0x1891/0x1c50 [nf_tables]
[  286.449144]  nfnetlink_rcv+0x1148/0x13d0 [nfnetlink]
[ ... ]

Signed-off-by: Taehee Yoo <ap420073@gmail.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
anthraxx referenced this issue in anthraxx/linux-hardened Jul 27, 2018
commit 36eb8ff upstream.

Crash dump shows following instructions

crash> bt
PID: 0      TASK: ffffffffbe412480  CPU: 0   COMMAND: "swapper/0"
 #0 [ffff891ee0003868] machine_kexec at ffffffffbd063ef1
 #1 [ffff891ee00038c8] __crash_kexec at ffffffffbd12b6f2
 #2 [ffff891ee0003998] crash_kexec at ffffffffbd12c84c
 #3 [ffff891ee00039b8] oops_end at ffffffffbd030f0a
 #4 [ffff891ee00039e0] no_context at ffffffffbd074643
 #5 [ffff891ee0003a40] __bad_area_nosemaphore at ffffffffbd07496e
 #6 [ffff891ee0003a90] bad_area_nosemaphore at ffffffffbd074a64
 #7 [ffff891ee0003aa0] __do_page_fault at ffffffffbd074b0a
 #8 [ffff891ee0003b18] do_page_fault at ffffffffbd074fc8
 #9 [ffff891ee0003b50] page_fault at ffffffffbda01925
    [exception RIP: qlt_schedule_sess_for_deletion+15]
    RIP: ffffffffc02e526f  RSP: ffff891ee0003c08  RFLAGS: 00010046
    RAX: 0000000000000000  RBX: 0000000000000000  RCX: ffffffffc0307847
    RDX: 00000000000020e6  RSI: ffff891edbc377c8  RDI: 0000000000000000
    RBP: ffff891ee0003c18   R8: ffffffffc02f0b20   R9: 0000000000000250
    R10: 0000000000000258  R11: 000000000000b780  R12: ffff891ed9b43000
    R13: 00000000000000f0  R14: 0000000000000006  R15: ffff891edbc377c8
    ORIG_RAX: ffffffffffffffff  CS: 0010  SS: 0018
 #10 [ffff891ee0003c20] qla2x00_fcport_event_handler at ffffffffc02853d3 [qla2xxx]
 #11 [ffff891ee0003cf0] __dta_qla24xx_async_gnl_sp_done_333 at ffffffffc0285a1d [qla2xxx]
 #12 [ffff891ee0003de8] qla24xx_process_response_queue at ffffffffc02a2eb5 [qla2xxx]
 #13 [ffff891ee0003e88] qla24xx_msix_rsp_q at ffffffffc02a5403 [qla2xxx]
 #14 [ffff891ee0003ec0] __handle_irq_event_percpu at ffffffffbd0f4c59
 #15 [ffff891ee0003f10] handle_irq_event_percpu at ffffffffbd0f4e02
 #16 [ffff891ee0003f40] handle_irq_event at ffffffffbd0f4e90
 #17 [ffff891ee0003f68] handle_edge_irq at ffffffffbd0f8984
 #18 [ffff891ee0003f88] handle_irq at ffffffffbd0305d5
 #19 [ffff891ee0003fb8] do_IRQ at ffffffffbda02a18
 --- <IRQ stack> ---
 #20 [ffffffffbe403d30] ret_from_intr at ffffffffbda0094e
    [exception RIP: unknown or invalid address]
    RIP: 000000000000001f  RSP: 0000000000000000  RFLAGS: fff3b8c2091ebb3f
    RAX: ffffbba5a0000200  RBX: 0000be8cdfa8f9fa  RCX: 0000000000000018
    RDX: 0000000000000101  RSI: 000000000000015d  RDI: 0000000000000193
    RBP: 0000000000000083   R8: ffffffffbe403e38   R9: 0000000000000002
    R10: 0000000000000000  R11: ffffffffbe56b820  R12: ffff891ee001cf00
    R13: ffffffffbd11c0a4  R14: ffffffffbe403d60  R15: 0000000000000001
    ORIG_RAX: ffff891ee0022ac0  CS: 0000  SS: ffffffffffffffb9
 bt: WARNING: possibly bogus exception frame
 #21 [ffffffffbe403dd8] cpuidle_enter_state at ffffffffbd67c6fd
 #22 [ffffffffbe403e40] cpuidle_enter at ffffffffbd67c907
 #23 [ffffffffbe403e50] call_cpuidle at ffffffffbd0d98f3
 #24 [ffffffffbe403e60] do_idle at ffffffffbd0d9b42
 #25 [ffffffffbe403e98] cpu_startup_entry at ffffffffbd0d9da3
 #26 [ffffffffbe403ec0] rest_init at ffffffffbd81d4aa
 #27 [ffffffffbe403ed0] start_kernel at ffffffffbe67d2ca
 #28 [ffffffffbe403f28] x86_64_start_reservations at ffffffffbe67c675
 #29 [ffffffffbe403f38] x86_64_start_kernel at ffffffffbe67c6eb
 #30 [ffffffffbe403f50] secondary_startup_64 at ffffffffbd0000d5

Fixes: 040036b ("scsi: qla2xxx: Delay loop id allocation at login")
Cc: <stable@vger.kernel.org> # v4.17+
Signed-off-by: Chuck Anderson <chuck.anderson@oracle.com>
Signed-off-by: Himanshu Madhani <himanshu.madhani@cavium.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
anthraxx referenced this issue in anthraxx/linux-hardened Sep 9, 2018
commit a5ba1d9 upstream.

We have reports of the following crash:

    PID: 7 TASK: ffff88085c6d61c0 CPU: 1 COMMAND: "kworker/u25:0"
    #0 [ffff88085c6db710] machine_kexec at ffffffff81046239
    #1 [ffff88085c6db760] crash_kexec at ffffffff810fc248
    #2 [ffff88085c6db830] oops_end at ffffffff81008ae7
    #3 [ffff88085c6db860] no_context at ffffffff81050b8f
    #4 [ffff88085c6db8b0] __bad_area_nosemaphore at ffffffff81050d75
    #5 [ffff88085c6db900] bad_area_nosemaphore at ffffffff81050e83
    #6 [ffff88085c6db910] __do_page_fault at ffffffff8105132e
    #7 [ffff88085c6db9b0] do_page_fault at ffffffff8105152c
    #8 [ffff88085c6db9c0] page_fault at ffffffff81a3f122
    [exception RIP: uart_put_char+149]
    RIP: ffffffff814b67b5 RSP: ffff88085c6dba78 RFLAGS: 00010006
    RAX: 0000000000000292 RBX: ffffffff827c5120 RCX: 0000000000000081
    RDX: 0000000000000000 RSI: 000000000000005f RDI: ffffffff827c5120
    RBP: ffff88085c6dba98 R8: 000000000000012c R9: ffffffff822ea320
    R10: ffff88085fe4db04 R11: 0000000000000001 R12: ffff881059f9c000
    R13: 0000000000000001 R14: 000000000000005f R15: 0000000000000fba
    ORIG_RAX: ffffffffffffffff CS: 0010 SS: 0018
    #9 [ffff88085c6dbaa0] tty_put_char at ffffffff81497544
    #10 [ffff88085c6dbac0] do_output_char at ffffffff8149c91c
    #11 [ffff88085c6dbae0] __process_echoes at ffffffff8149cb8b
    #12 [ffff88085c6dbb30] commit_echoes at ffffffff8149cdc2
    #13 [ffff88085c6dbb60] n_tty_receive_buf_fast at ffffffff8149e49b
    #14 [ffff88085c6dbbc0] __receive_buf at ffffffff8149ef5a
    #15 [ffff88085c6dbc20] n_tty_receive_buf_common at ffffffff8149f016
    #16 [ffff88085c6dbca0] n_tty_receive_buf2 at ffffffff8149f194
    #17 [ffff88085c6dbcb0] flush_to_ldisc at ffffffff814a238a
    #18 [ffff88085c6dbd50] process_one_work at ffffffff81090be2
    #19 [ffff88085c6dbe20] worker_thread at ffffffff81091b4d
    #20 [ffff88085c6dbeb0] kthread at ffffffff81096384
    #21 [ffff88085c6dbf50] ret_from_fork at ffffffff81a3d69f​

after slogging through some dissasembly:

ffffffff814b6720 <uart_put_char>:
ffffffff814b6720:	55                   	push   %rbp
ffffffff814b6721:	48 89 e5             	mov    %rsp,%rbp
ffffffff814b6724:	48 83 ec 20          	sub    $0x20,%rsp
ffffffff814b6728:	48 89 1c 24          	mov    %rbx,(%rsp)
ffffffff814b672c:	4c 89 64 24 08       	mov    %r12,0x8(%rsp)
ffffffff814b6731:	4c 89 6c 24 10       	mov    %r13,0x10(%rsp)
ffffffff814b6736:	4c 89 74 24 18       	mov    %r14,0x18(%rsp)
ffffffff814b673b:	e8 b0 8e 58 00       	callq  ffffffff81a3f5f0 <mcount>
ffffffff814b6740:	4c 8b a7 88 02 00 00 	mov    0x288(%rdi),%r12
ffffffff814b6747:	45 31 ed             	xor    %r13d,%r13d
ffffffff814b674a:	41 89 f6             	mov    %esi,%r14d
ffffffff814b674d:	49 83 bc 24 70 01 00 	cmpq   $0x0,0x170(%r12)
ffffffff814b6754:	00 00
ffffffff814b6756:	49 8b 9c 24 80 01 00 	mov    0x180(%r12),%rbx
ffffffff814b675d:	00
ffffffff814b675e:	74 2f                	je     ffffffff814b678f <uart_put_char+0x6f>
ffffffff814b6760:	48 89 df             	mov    %rbx,%rdi
ffffffff814b6763:	e8 a8 67 58 00       	callq  ffffffff81a3cf10 <_raw_spin_lock_irqsave>
ffffffff814b6768:	41 8b 8c 24 78 01 00 	mov    0x178(%r12),%ecx
ffffffff814b676f:	00
ffffffff814b6770:	89 ca                	mov    %ecx,%edx
ffffffff814b6772:	f7 d2                	not    %edx
ffffffff814b6774:	41 03 94 24 7c 01 00 	add    0x17c(%r12),%edx
ffffffff814b677b:	00
ffffffff814b677c:	81 e2 ff 0f 00 00    	and    $0xfff,%edx
ffffffff814b6782:	75 23                	jne    ffffffff814b67a7 <uart_put_char+0x87>
ffffffff814b6784:	48 89 c6             	mov    %rax,%rsi
ffffffff814b6787:	48 89 df             	mov    %rbx,%rdi
ffffffff814b678a:	e8 e1 64 58 00       	callq  ffffffff81a3cc70 <_raw_spin_unlock_irqrestore>
ffffffff814b678f:	44 89 e8             	mov    %r13d,%eax
ffffffff814b6792:	48 8b 1c 24          	mov    (%rsp),%rbx
ffffffff814b6796:	4c 8b 64 24 08       	mov    0x8(%rsp),%r12
ffffffff814b679b:	4c 8b 6c 24 10       	mov    0x10(%rsp),%r13
ffffffff814b67a0:	4c 8b 74 24 18       	mov    0x18(%rsp),%r14
ffffffff814b67a5:	c9                   	leaveq
ffffffff814b67a6:	c3                   	retq
ffffffff814b67a7:	49 8b 94 24 70 01 00 	mov    0x170(%r12),%rdx
ffffffff814b67ae:	00
ffffffff814b67af:	48 63 c9             	movslq %ecx,%rcx
ffffffff814b67b2:	41 b5 01             	mov    $0x1,%r13b
ffffffff814b67b5:	44 88 34 0a          	mov    %r14b,(%rdx,%rcx,1)
ffffffff814b67b9:	41 8b 94 24 78 01 00 	mov    0x178(%r12),%edx
ffffffff814b67c0:	00
ffffffff814b67c1:	83 c2 01             	add    $0x1,%edx
ffffffff814b67c4:	81 e2 ff 0f 00 00    	and    $0xfff,%edx
ffffffff814b67ca:	41 89 94 24 78 01 00 	mov    %edx,0x178(%r12)
ffffffff814b67d1:	00
ffffffff814b67d2:	eb b0                	jmp    ffffffff814b6784 <uart_put_char+0x64>
ffffffff814b67d4:	66 66 66 2e 0f 1f 84 	data32 data32 nopw %cs:0x0(%rax,%rax,1)
ffffffff814b67db:	00 00 00 00 00

for our build, this is crashing at:

    circ->buf[circ->head] = c;

Looking in uart_port_startup(), it seems that circ->buf (state->xmit.buf)
protected by the "per-port mutex", which based on uart_port_check() is
state->port.mutex. Indeed, the lock acquired in uart_put_char() is
uport->lock, i.e. not the same lock.

Anyway, since the lock is not acquired, if uart_shutdown() is called, the
last chunk of that function may release state->xmit.buf before its assigned
to null, and cause the race above.

To fix it, let's lock uport->lock when allocating/deallocating
state->xmit.buf in addition to the per-port mutex.

v2: switch to locking uport->lock on allocation/deallocation instead of
    locking the per-port mutex in uart_put_char. Note that since
    uport->lock is a spin lock, we have to switch the allocation to
    GFP_ATOMIC.
v3: move the allocation outside the lock, so we can switch back to
    GFP_KERNEL

Signed-off-by: Tycho Andersen <tycho@tycho.ws>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
anthraxx referenced this issue in anthraxx/linux-hardened Sep 9, 2018
commit a5ba1d9 upstream.

We have reports of the following crash:

    PID: 7 TASK: ffff88085c6d61c0 CPU: 1 COMMAND: "kworker/u25:0"
    #0 [ffff88085c6db710] machine_kexec at ffffffff81046239
    #1 [ffff88085c6db760] crash_kexec at ffffffff810fc248
    #2 [ffff88085c6db830] oops_end at ffffffff81008ae7
    #3 [ffff88085c6db860] no_context at ffffffff81050b8f
    #4 [ffff88085c6db8b0] __bad_area_nosemaphore at ffffffff81050d75
    #5 [ffff88085c6db900] bad_area_nosemaphore at ffffffff81050e83
    #6 [ffff88085c6db910] __do_page_fault at ffffffff8105132e
    #7 [ffff88085c6db9b0] do_page_fault at ffffffff8105152c
    #8 [ffff88085c6db9c0] page_fault at ffffffff81a3f122
    [exception RIP: uart_put_char+149]
    RIP: ffffffff814b67b5 RSP: ffff88085c6dba78 RFLAGS: 00010006
    RAX: 0000000000000292 RBX: ffffffff827c5120 RCX: 0000000000000081
    RDX: 0000000000000000 RSI: 000000000000005f RDI: ffffffff827c5120
    RBP: ffff88085c6dba98 R8: 000000000000012c R9: ffffffff822ea320
    R10: ffff88085fe4db04 R11: 0000000000000001 R12: ffff881059f9c000
    R13: 0000000000000001 R14: 000000000000005f R15: 0000000000000fba
    ORIG_RAX: ffffffffffffffff CS: 0010 SS: 0018
    #9 [ffff88085c6dbaa0] tty_put_char at ffffffff81497544
    #10 [ffff88085c6dbac0] do_output_char at ffffffff8149c91c
    #11 [ffff88085c6dbae0] __process_echoes at ffffffff8149cb8b
    #12 [ffff88085c6dbb30] commit_echoes at ffffffff8149cdc2
    #13 [ffff88085c6dbb60] n_tty_receive_buf_fast at ffffffff8149e49b
    #14 [ffff88085c6dbbc0] __receive_buf at ffffffff8149ef5a
    #15 [ffff88085c6dbc20] n_tty_receive_buf_common at ffffffff8149f016
    #16 [ffff88085c6dbca0] n_tty_receive_buf2 at ffffffff8149f194
    #17 [ffff88085c6dbcb0] flush_to_ldisc at ffffffff814a238a
    #18 [ffff88085c6dbd50] process_one_work at ffffffff81090be2
    #19 [ffff88085c6dbe20] worker_thread at ffffffff81091b4d
    #20 [ffff88085c6dbeb0] kthread at ffffffff81096384
    #21 [ffff88085c6dbf50] ret_from_fork at ffffffff81a3d69f​

after slogging through some dissasembly:

ffffffff814b6720 <uart_put_char>:
ffffffff814b6720:	55                   	push   %rbp
ffffffff814b6721:	48 89 e5             	mov    %rsp,%rbp
ffffffff814b6724:	48 83 ec 20          	sub    $0x20,%rsp
ffffffff814b6728:	48 89 1c 24          	mov    %rbx,(%rsp)
ffffffff814b672c:	4c 89 64 24 08       	mov    %r12,0x8(%rsp)
ffffffff814b6731:	4c 89 6c 24 10       	mov    %r13,0x10(%rsp)
ffffffff814b6736:	4c 89 74 24 18       	mov    %r14,0x18(%rsp)
ffffffff814b673b:	e8 b0 8e 58 00       	callq  ffffffff81a3f5f0 <mcount>
ffffffff814b6740:	4c 8b a7 88 02 00 00 	mov    0x288(%rdi),%r12
ffffffff814b6747:	45 31 ed             	xor    %r13d,%r13d
ffffffff814b674a:	41 89 f6             	mov    %esi,%r14d
ffffffff814b674d:	49 83 bc 24 70 01 00 	cmpq   $0x0,0x170(%r12)
ffffffff814b6754:	00 00
ffffffff814b6756:	49 8b 9c 24 80 01 00 	mov    0x180(%r12),%rbx
ffffffff814b675d:	00
ffffffff814b675e:	74 2f                	je     ffffffff814b678f <uart_put_char+0x6f>
ffffffff814b6760:	48 89 df             	mov    %rbx,%rdi
ffffffff814b6763:	e8 a8 67 58 00       	callq  ffffffff81a3cf10 <_raw_spin_lock_irqsave>
ffffffff814b6768:	41 8b 8c 24 78 01 00 	mov    0x178(%r12),%ecx
ffffffff814b676f:	00
ffffffff814b6770:	89 ca                	mov    %ecx,%edx
ffffffff814b6772:	f7 d2                	not    %edx
ffffffff814b6774:	41 03 94 24 7c 01 00 	add    0x17c(%r12),%edx
ffffffff814b677b:	00
ffffffff814b677c:	81 e2 ff 0f 00 00    	and    $0xfff,%edx
ffffffff814b6782:	75 23                	jne    ffffffff814b67a7 <uart_put_char+0x87>
ffffffff814b6784:	48 89 c6             	mov    %rax,%rsi
ffffffff814b6787:	48 89 df             	mov    %rbx,%rdi
ffffffff814b678a:	e8 e1 64 58 00       	callq  ffffffff81a3cc70 <_raw_spin_unlock_irqrestore>
ffffffff814b678f:	44 89 e8             	mov    %r13d,%eax
ffffffff814b6792:	48 8b 1c 24          	mov    (%rsp),%rbx
ffffffff814b6796:	4c 8b 64 24 08       	mov    0x8(%rsp),%r12
ffffffff814b679b:	4c 8b 6c 24 10       	mov    0x10(%rsp),%r13
ffffffff814b67a0:	4c 8b 74 24 18       	mov    0x18(%rsp),%r14
ffffffff814b67a5:	c9                   	leaveq
ffffffff814b67a6:	c3                   	retq
ffffffff814b67a7:	49 8b 94 24 70 01 00 	mov    0x170(%r12),%rdx
ffffffff814b67ae:	00
ffffffff814b67af:	48 63 c9             	movslq %ecx,%rcx
ffffffff814b67b2:	41 b5 01             	mov    $0x1,%r13b
ffffffff814b67b5:	44 88 34 0a          	mov    %r14b,(%rdx,%rcx,1)
ffffffff814b67b9:	41 8b 94 24 78 01 00 	mov    0x178(%r12),%edx
ffffffff814b67c0:	00
ffffffff814b67c1:	83 c2 01             	add    $0x1,%edx
ffffffff814b67c4:	81 e2 ff 0f 00 00    	and    $0xfff,%edx
ffffffff814b67ca:	41 89 94 24 78 01 00 	mov    %edx,0x178(%r12)
ffffffff814b67d1:	00
ffffffff814b67d2:	eb b0                	jmp    ffffffff814b6784 <uart_put_char+0x64>
ffffffff814b67d4:	66 66 66 2e 0f 1f 84 	data32 data32 nopw %cs:0x0(%rax,%rax,1)
ffffffff814b67db:	00 00 00 00 00

for our build, this is crashing at:

    circ->buf[circ->head] = c;

Looking in uart_port_startup(), it seems that circ->buf (state->xmit.buf)
protected by the "per-port mutex", which based on uart_port_check() is
state->port.mutex. Indeed, the lock acquired in uart_put_char() is
uport->lock, i.e. not the same lock.

Anyway, since the lock is not acquired, if uart_shutdown() is called, the
last chunk of that function may release state->xmit.buf before its assigned
to null, and cause the race above.

To fix it, let's lock uport->lock when allocating/deallocating
state->xmit.buf in addition to the per-port mutex.

v2: switch to locking uport->lock on allocation/deallocation instead of
    locking the per-port mutex in uart_put_char. Note that since
    uport->lock is a spin lock, we have to switch the allocation to
    GFP_ATOMIC.
v3: move the allocation outside the lock, so we can switch back to
    GFP_KERNEL

Signed-off-by: Tycho Andersen <tycho@tycho.ws>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
randomhydrosol pushed a commit to randomhydrosol/linux-hardened that referenced this issue Dec 1, 2018
It was observed that a process blocked indefintely in
__fscache_read_or_alloc_page(), waiting for FSCACHE_COOKIE_LOOKING_UP
to be cleared via fscache_wait_for_deferred_lookup().

At this time, ->backing_objects was empty, which would normaly prevent
__fscache_read_or_alloc_page() from getting to the point of waiting.
This implies that ->backing_objects was cleared *after*
__fscache_read_or_alloc_page was was entered.

When an object is "killed" and then "dropped",
FSCACHE_COOKIE_LOOKING_UP is cleared in fscache_lookup_failure(), then
KILL_OBJECT and DROP_OBJECT are "called" and only in DROP_OBJECT is
->backing_objects cleared.  This leaves a window where
something else can set FSCACHE_COOKIE_LOOKING_UP and
__fscache_read_or_alloc_page() can start waiting, before
->backing_objects is cleared

There is some uncertainty in this analysis, but it seems to be fit the
observations.  Adding the wake in this patch will be handled correctly
by __fscache_read_or_alloc_page(), as it checks if ->backing_objects
is empty again, after waiting.

Customer which reported the hang, also report that the hang cannot be
reproduced with this fix.

The backtrace for the blocked process looked like:

PID: 29360  TASK: ffff881ff2ac0f80  CPU: 3   COMMAND: "zsh"
 #0 [ffff881ff43efbf8] schedule at ffffffff815e56f1
 GrapheneOS#1 [ffff881ff43efc58] bit_wait at ffffffff815e64ed
 GrapheneOS#2 [ffff881ff43efc68] __wait_on_bit at ffffffff815e61b8
 GrapheneOS#3 [ffff881ff43efca0] out_of_line_wait_on_bit at ffffffff815e625e
 GrapheneOS#4 [ffff881ff43efd08] fscache_wait_for_deferred_lookup at ffffffffa04f2e8f [fscache]
 GrapheneOS#5 [ffff881ff43efd18] __fscache_read_or_alloc_page at ffffffffa04f2ffe [fscache]
 GrapheneOS#6 [ffff881ff43efd58] __nfs_readpage_from_fscache at ffffffffa0679668 [nfs]
 GrapheneOS#7 [ffff881ff43efd78] nfs_readpage at ffffffffa067092b [nfs]
 GrapheneOS#8 [ffff881ff43efda0] generic_file_read_iter at ffffffff81187a73
 GrapheneOS#9 [ffff881ff43efe50] nfs_file_read at ffffffffa066544b [nfs]
GrapheneOS#10 [ffff881ff43efe70] __vfs_read at ffffffff811fc756
GrapheneOS#11 [ffff881ff43efee8] vfs_read at ffffffff811fccfa
GrapheneOS#12 [ffff881ff43eff18] sys_read at ffffffff811fda62
GrapheneOS#13 [ffff881ff43eff50] entry_SYSCALL_64_fastpath at ffffffff815e986e

Signed-off-by: NeilBrown <neilb@suse.com>
Signed-off-by: David Howells <dhowells@redhat.com>
anthraxx referenced this issue in anthraxx/linux-hardened Dec 18, 2018
[ Upstream commit c5a94f4 ]

It was observed that a process blocked indefintely in
__fscache_read_or_alloc_page(), waiting for FSCACHE_COOKIE_LOOKING_UP
to be cleared via fscache_wait_for_deferred_lookup().

At this time, ->backing_objects was empty, which would normaly prevent
__fscache_read_or_alloc_page() from getting to the point of waiting.
This implies that ->backing_objects was cleared *after*
__fscache_read_or_alloc_page was was entered.

When an object is "killed" and then "dropped",
FSCACHE_COOKIE_LOOKING_UP is cleared in fscache_lookup_failure(), then
KILL_OBJECT and DROP_OBJECT are "called" and only in DROP_OBJECT is
->backing_objects cleared.  This leaves a window where
something else can set FSCACHE_COOKIE_LOOKING_UP and
__fscache_read_or_alloc_page() can start waiting, before
->backing_objects is cleared

There is some uncertainty in this analysis, but it seems to be fit the
observations.  Adding the wake in this patch will be handled correctly
by __fscache_read_or_alloc_page(), as it checks if ->backing_objects
is empty again, after waiting.

Customer which reported the hang, also report that the hang cannot be
reproduced with this fix.

The backtrace for the blocked process looked like:

PID: 29360  TASK: ffff881ff2ac0f80  CPU: 3   COMMAND: "zsh"
 #0 [ffff881ff43efbf8] schedule at ffffffff815e56f1
 #1 [ffff881ff43efc58] bit_wait at ffffffff815e64ed
 #2 [ffff881ff43efc68] __wait_on_bit at ffffffff815e61b8
 #3 [ffff881ff43efca0] out_of_line_wait_on_bit at ffffffff815e625e
 #4 [ffff881ff43efd08] fscache_wait_for_deferred_lookup at ffffffffa04f2e8f [fscache]
 #5 [ffff881ff43efd18] __fscache_read_or_alloc_page at ffffffffa04f2ffe [fscache]
 #6 [ffff881ff43efd58] __nfs_readpage_from_fscache at ffffffffa0679668 [nfs]
 #7 [ffff881ff43efd78] nfs_readpage at ffffffffa067092b [nfs]
 #8 [ffff881ff43efda0] generic_file_read_iter at ffffffff81187a73
 #9 [ffff881ff43efe50] nfs_file_read at ffffffffa066544b [nfs]
#10 [ffff881ff43efe70] __vfs_read at ffffffff811fc756
#11 [ffff881ff43efee8] vfs_read at ffffffff811fccfa
#12 [ffff881ff43eff18] sys_read at ffffffff811fda62
#13 [ffff881ff43eff50] entry_SYSCALL_64_fastpath at ffffffff815e986e

Signed-off-by: NeilBrown <neilb@suse.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
anthraxx referenced this issue in anthraxx/linux-hardened Dec 18, 2018
[ Upstream commit c5a94f4 ]

It was observed that a process blocked indefintely in
__fscache_read_or_alloc_page(), waiting for FSCACHE_COOKIE_LOOKING_UP
to be cleared via fscache_wait_for_deferred_lookup().

At this time, ->backing_objects was empty, which would normaly prevent
__fscache_read_or_alloc_page() from getting to the point of waiting.
This implies that ->backing_objects was cleared *after*
__fscache_read_or_alloc_page was was entered.

When an object is "killed" and then "dropped",
FSCACHE_COOKIE_LOOKING_UP is cleared in fscache_lookup_failure(), then
KILL_OBJECT and DROP_OBJECT are "called" and only in DROP_OBJECT is
->backing_objects cleared.  This leaves a window where
something else can set FSCACHE_COOKIE_LOOKING_UP and
__fscache_read_or_alloc_page() can start waiting, before
->backing_objects is cleared

There is some uncertainty in this analysis, but it seems to be fit the
observations.  Adding the wake in this patch will be handled correctly
by __fscache_read_or_alloc_page(), as it checks if ->backing_objects
is empty again, after waiting.

Customer which reported the hang, also report that the hang cannot be
reproduced with this fix.

The backtrace for the blocked process looked like:

PID: 29360  TASK: ffff881ff2ac0f80  CPU: 3   COMMAND: "zsh"
 #0 [ffff881ff43efbf8] schedule at ffffffff815e56f1
 #1 [ffff881ff43efc58] bit_wait at ffffffff815e64ed
 #2 [ffff881ff43efc68] __wait_on_bit at ffffffff815e61b8
 #3 [ffff881ff43efca0] out_of_line_wait_on_bit at ffffffff815e625e
 #4 [ffff881ff43efd08] fscache_wait_for_deferred_lookup at ffffffffa04f2e8f [fscache]
 #5 [ffff881ff43efd18] __fscache_read_or_alloc_page at ffffffffa04f2ffe [fscache]
 #6 [ffff881ff43efd58] __nfs_readpage_from_fscache at ffffffffa0679668 [nfs]
 #7 [ffff881ff43efd78] nfs_readpage at ffffffffa067092b [nfs]
 #8 [ffff881ff43efda0] generic_file_read_iter at ffffffff81187a73
 #9 [ffff881ff43efe50] nfs_file_read at ffffffffa066544b [nfs]
#10 [ffff881ff43efe70] __vfs_read at ffffffff811fc756
#11 [ffff881ff43efee8] vfs_read at ffffffff811fccfa
#12 [ffff881ff43eff18] sys_read at ffffffff811fda62
#13 [ffff881ff43eff50] entry_SYSCALL_64_fastpath at ffffffff815e986e

Signed-off-by: NeilBrown <neilb@suse.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
randomhydrosol pushed a commit to randomhydrosol/linux-hardened that referenced this issue Dec 25, 2018
Commit 9b6f7e1 ("mm: rework memcg kernel stack accounting") will
result in fork failing if allocating a kernel stack for a task in
dup_task_struct exceeds the kernel memory allowance for that cgroup.

Unfortunately, it also results in a crash.

This is due to the code jumping to free_stack and calling
free_thread_stack when the memcg kernel stack charge fails, but without
tsk->stack pointing at the freshly allocated stack.

This in turn results in the vfree_atomic in free_thread_stack oopsing
with a backtrace like this:

GrapheneOS#5 [ffffc900244efc88] die at ffffffff8101f0ab
 GrapheneOS#6 [ffffc900244efcb8] do_general_protection at ffffffff8101cb86
 GrapheneOS#7 [ffffc900244efce0] general_protection at ffffffff818ff082
    [exception RIP: llist_add_batch+7]
    RIP: ffffffff8150d487  RSP: ffffc900244efd98  RFLAGS: 00010282
    RAX: 0000000000000000  RBX: ffff88085ef55980  RCX: 0000000000000000
    RDX: ffff88085ef55980  RSI: 343834343531203a  RDI: 343834343531203a
    RBP: ffffc900244efd98   R8: 0000000000000001   R9: ffff8808578c3600
    R10: 0000000000000000  R11: 0000000000000001  R12: ffff88029f6c21c0
    R13: 0000000000000286  R14: ffff880147759b00  R15: 0000000000000000
    ORIG_RAX: ffffffffffffffff  CS: 0010  SS: 0018
 GrapheneOS#8 [ffffc900244efda0] vfree_atomic at ffffffff811df2c7
 GrapheneOS#9 [ffffc900244efdb8] copy_process at ffffffff81086e37
GrapheneOS#10 [ffffc900244efe98] _do_fork at ffffffff810884e0
GrapheneOS#11 [ffffc900244eff10] sys_vfork at ffffffff810887ff
GrapheneOS#12 [ffffc900244eff20] do_syscall_64 at ffffffff81002a43
    RIP: 000000000049b948  RSP: 00007ffcdb307830  RFLAGS: 00000246
    RAX: ffffffffffffffda  RBX: 0000000000896030  RCX: 000000000049b948
    RDX: 0000000000000000  RSI: 00007ffcdb307790  RDI: 00000000005d7421
    RBP: 000000000067370f   R8: 00007ffcdb3077b0   R9: 000000000001ed00
    R10: 0000000000000008  R11: 0000000000000246  R12: 0000000000000040
    R13: 000000000000000f  R14: 0000000000000000  R15: 000000000088d018
    ORIG_RAX: 000000000000003a  CS: 0033  SS: 002b

The simplest fix is to assign tsk->stack right where it is allocated.

Link: http://lkml.kernel.org/r/20181214231726.7ee4843c@imladris.surriel.com
Fixes: 9b6f7e1 ("mm: rework memcg kernel stack accounting")
Signed-off-by: Rik van Riel <riel@surriel.com>
Acked-by: Roman Gushchin <guro@fb.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Tejun Heo <tj@kernel.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
randomhydrosol pushed a commit to randomhydrosol/linux-hardened that referenced this issue Jan 25, 2019
Some IPMI modules (e.g. ibmpex_msg_handler()) will have ipmi_usr_hdlr
handlers that call ipmi_free_recv_msg() directly. This will essentially
kfree(msg), leading to use-after-free.

This does not happen in the ipmi_devintf module, which will queue the
message and run ipmi_free_recv_msg() later.

BUG: KASAN: use-after-free in deliver_response+0x12f/0x1b0
Read of size 8 at addr ffff888a7bf20018 by task ksoftirqd/3/27
CPU: 3 PID: 27 Comm: ksoftirqd/3 Tainted: G           O      4.19.11-amd64-ani99-debug GrapheneOS#12.0.1.601133+pv
Hardware name: AppNeta r1000/X11SPW-TF, BIOS 2.1a-AP 09/17/2018
Call Trace:
dump_stack+0x92/0xeb
print_address_description+0x73/0x290
kasan_report+0x258/0x380
deliver_response+0x12f/0x1b0
? ipmi_free_recv_msg+0x50/0x50
deliver_local_response+0xe/0x50
handle_one_recv_msg+0x37a/0x21d0
handle_new_recv_msgs+0x1ce/0x440
...

Allocated by task 9885:
kasan_kmalloc+0xa0/0xd0
kmem_cache_alloc_trace+0x116/0x290
ipmi_alloc_recv_msg+0x28/0x70
i_ipmi_request+0xb4a/0x1640
ipmi_request_settime+0x1b8/0x1e0
...

Freed by task 27:
__kasan_slab_free+0x12e/0x180
kfree+0xe9/0x280
deliver_response+0x122/0x1b0
deliver_local_response+0xe/0x50
handle_one_recv_msg+0x37a/0x21d0
handle_new_recv_msgs+0x1ce/0x440
tasklet_action_common.isra.19+0xc4/0x250
__do_softirq+0x11f/0x51f

Fixes: e86ee2d ("ipmi: Rework locking and shutdown for hot remove")
Cc: stable@vger.kernel.org # 4.18
Signed-off-by: Fred Klassen <fklassen@appneta.com>
Signed-off-by: Corey Minyard <cminyard@mvista.com>
anthraxx referenced this issue in anthraxx/linux-hardened Jan 28, 2019
commit 479d6b3 upstream.

Some IPMI modules (e.g. ibmpex_msg_handler()) will have ipmi_usr_hdlr
handlers that call ipmi_free_recv_msg() directly. This will essentially
kfree(msg), leading to use-after-free.

This does not happen in the ipmi_devintf module, which will queue the
message and run ipmi_free_recv_msg() later.

BUG: KASAN: use-after-free in deliver_response+0x12f/0x1b0
Read of size 8 at addr ffff888a7bf20018 by task ksoftirqd/3/27
CPU: 3 PID: 27 Comm: ksoftirqd/3 Tainted: G           O      4.19.11-amd64-ani99-debug #12.0.1.601133+pv
Hardware name: AppNeta r1000/X11SPW-TF, BIOS 2.1a-AP 09/17/2018
Call Trace:
dump_stack+0x92/0xeb
print_address_description+0x73/0x290
kasan_report+0x258/0x380
deliver_response+0x12f/0x1b0
? ipmi_free_recv_msg+0x50/0x50
deliver_local_response+0xe/0x50
handle_one_recv_msg+0x37a/0x21d0
handle_new_recv_msgs+0x1ce/0x440
...

Allocated by task 9885:
kasan_kmalloc+0xa0/0xd0
kmem_cache_alloc_trace+0x116/0x290
ipmi_alloc_recv_msg+0x28/0x70
i_ipmi_request+0xb4a/0x1640
ipmi_request_settime+0x1b8/0x1e0
...

Freed by task 27:
__kasan_slab_free+0x12e/0x180
kfree+0xe9/0x280
deliver_response+0x122/0x1b0
deliver_local_response+0xe/0x50
handle_one_recv_msg+0x37a/0x21d0
handle_new_recv_msgs+0x1ce/0x440
tasklet_action_common.isra.19+0xc4/0x250
__do_softirq+0x11f/0x51f

Fixes: e86ee2d ("ipmi: Rework locking and shutdown for hot remove")
Cc: stable@vger.kernel.org # 4.18
Signed-off-by: Fred Klassen <fklassen@appneta.com>
Signed-off-by: Corey Minyard <cminyard@mvista.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
anthraxx referenced this issue in anthraxx/linux-hardened Jan 28, 2019
commit 479d6b3 upstream.

Some IPMI modules (e.g. ibmpex_msg_handler()) will have ipmi_usr_hdlr
handlers that call ipmi_free_recv_msg() directly. This will essentially
kfree(msg), leading to use-after-free.

This does not happen in the ipmi_devintf module, which will queue the
message and run ipmi_free_recv_msg() later.

BUG: KASAN: use-after-free in deliver_response+0x12f/0x1b0
Read of size 8 at addr ffff888a7bf20018 by task ksoftirqd/3/27
CPU: 3 PID: 27 Comm: ksoftirqd/3 Tainted: G           O      4.19.11-amd64-ani99-debug #12.0.1.601133+pv
Hardware name: AppNeta r1000/X11SPW-TF, BIOS 2.1a-AP 09/17/2018
Call Trace:
dump_stack+0x92/0xeb
print_address_description+0x73/0x290
kasan_report+0x258/0x380
deliver_response+0x12f/0x1b0
? ipmi_free_recv_msg+0x50/0x50
deliver_local_response+0xe/0x50
handle_one_recv_msg+0x37a/0x21d0
handle_new_recv_msgs+0x1ce/0x440
...

Allocated by task 9885:
kasan_kmalloc+0xa0/0xd0
kmem_cache_alloc_trace+0x116/0x290
ipmi_alloc_recv_msg+0x28/0x70
i_ipmi_request+0xb4a/0x1640
ipmi_request_settime+0x1b8/0x1e0
...

Freed by task 27:
__kasan_slab_free+0x12e/0x180
kfree+0xe9/0x280
deliver_response+0x122/0x1b0
deliver_local_response+0xe/0x50
handle_one_recv_msg+0x37a/0x21d0
handle_new_recv_msgs+0x1ce/0x440
tasklet_action_common.isra.19+0xc4/0x250
__do_softirq+0x11f/0x51f

Fixes: e86ee2d ("ipmi: Rework locking and shutdown for hot remove")
Cc: stable@vger.kernel.org # 4.18
Signed-off-by: Fred Klassen <fklassen@appneta.com>
Signed-off-by: Corey Minyard <cminyard@mvista.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
randomhydrosol pushed a commit to randomhydrosol/linux-hardened that referenced this issue Mar 27, 2019
…r-free issue

The evlist should be destroyed before the perf session.

Detected with gcc's ASan:

  =================================================================
  ==27350==ERROR: AddressSanitizer: heap-use-after-free on address 0x62b000002e38 at pc 0x5611da276999 bp 0x7ffce8f1d1a0 sp 0x7ffce8f1d190
  WRITE of size 8 at 0x62b000002e38 thread T0
      #0 0x5611da276998 in __list_del /home/work/linux/tools/include/linux/list.h:89
      GrapheneOS#1 0x5611da276d4a in __list_del_entry /home/work/linux/tools/include/linux/list.h:102
      GrapheneOS#2 0x5611da276e77 in list_del_init /home/work/linux/tools/include/linux/list.h:145
      GrapheneOS#3 0x5611da2781cd in thread__put util/thread.c:130
      GrapheneOS#4 0x5611da2cc0a8 in __thread__zput util/thread.h:68
      GrapheneOS#5 0x5611da2d2dcb in hist_entry__delete util/hist.c:1148
      GrapheneOS#6 0x5611da2cdf91 in hists__delete_entry util/hist.c:337
      GrapheneOS#7 0x5611da2ce19e in hists__delete_entries util/hist.c:365
      GrapheneOS#8 0x5611da2db2ab in hists__delete_all_entries util/hist.c:2639
      GrapheneOS#9 0x5611da2db325 in hists_evsel__exit util/hist.c:2651
      GrapheneOS#10 0x5611da1c5352 in perf_evsel__exit util/evsel.c:1304
      GrapheneOS#11 0x5611da1c5390 in perf_evsel__delete util/evsel.c:1309
      GrapheneOS#12 0x5611da1b35f0 in perf_evlist__purge util/evlist.c:124
      GrapheneOS#13 0x5611da1b38e2 in perf_evlist__delete util/evlist.c:148
      GrapheneOS#14 0x5611da069781 in cmd_top /home/changbin/work/linux/tools/perf/builtin-top.c:1645
      GrapheneOS#15 0x5611da17d038 in run_builtin /home/changbin/work/linux/tools/perf/perf.c:302
      GrapheneOS#16 0x5611da17d577 in handle_internal_command /home/changbin/work/linux/tools/perf/perf.c:354
      GrapheneOS#17 0x5611da17d97b in run_argv /home/changbin/work/linux/tools/perf/perf.c:398
      GrapheneOS#18 0x5611da17e0e9 in main /home/changbin/work/linux/tools/perf/perf.c:520
      GrapheneOS#19 0x7fdcc970f09a in __libc_start_main (/lib/x86_64-linux-gnu/libc.so.6+0x2409a)
      GrapheneOS#20 0x5611d9ff35c9 in _start (/home/work/linux/tools/perf/perf+0x3e95c9)

  0x62b000002e38 is located 11320 bytes inside of 27448-byte region [0x62b000000200,0x62b000006d38)
  freed by thread T0 here:
      #0 0x7fdccb04ab70 in free (/usr/lib/x86_64-linux-gnu/libasan.so.5+0xedb70)
      GrapheneOS#1 0x5611da260df4 in perf_session__delete util/session.c:201
      GrapheneOS#2 0x5611da063de5 in __cmd_top /home/changbin/work/linux/tools/perf/builtin-top.c:1300
      GrapheneOS#3 0x5611da06973c in cmd_top /home/changbin/work/linux/tools/perf/builtin-top.c:1642
      GrapheneOS#4 0x5611da17d038 in run_builtin /home/changbin/work/linux/tools/perf/perf.c:302
      GrapheneOS#5 0x5611da17d577 in handle_internal_command /home/changbin/work/linux/tools/perf/perf.c:354
      GrapheneOS#6 0x5611da17d97b in run_argv /home/changbin/work/linux/tools/perf/perf.c:398
      GrapheneOS#7 0x5611da17e0e9 in main /home/changbin/work/linux/tools/perf/perf.c:520
      GrapheneOS#8 0x7fdcc970f09a in __libc_start_main (/lib/x86_64-linux-gnu/libc.so.6+0x2409a)

  previously allocated by thread T0 here:
      #0 0x7fdccb04b138 in calloc (/usr/lib/x86_64-linux-gnu/libasan.so.5+0xee138)
      GrapheneOS#1 0x5611da26010c in zalloc util/util.h:23
      GrapheneOS#2 0x5611da260824 in perf_session__new util/session.c:118
      GrapheneOS#3 0x5611da0633a6 in __cmd_top /home/changbin/work/linux/tools/perf/builtin-top.c:1192
      GrapheneOS#4 0x5611da06973c in cmd_top /home/changbin/work/linux/tools/perf/builtin-top.c:1642
      GrapheneOS#5 0x5611da17d038 in run_builtin /home/changbin/work/linux/tools/perf/perf.c:302
      GrapheneOS#6 0x5611da17d577 in handle_internal_command /home/changbin/work/linux/tools/perf/perf.c:354
      GrapheneOS#7 0x5611da17d97b in run_argv /home/changbin/work/linux/tools/perf/perf.c:398
      GrapheneOS#8 0x5611da17e0e9 in main /home/changbin/work/linux/tools/perf/perf.c:520
      GrapheneOS#9 0x7fdcc970f09a in __libc_start_main (/lib/x86_64-linux-gnu/libc.so.6+0x2409a)

  SUMMARY: AddressSanitizer: heap-use-after-free /home/work/linux/tools/include/linux/list.h:89 in __list_del
  Shadow bytes around the buggy address:
    0x0c567fff8570: fd fd fd fd fd fd fd fd fd fd fd fd fd fd fd fd
    0x0c567fff8580: fd fd fd fd fd fd fd fd fd fd fd fd fd fd fd fd
    0x0c567fff8590: fd fd fd fd fd fd fd fd fd fd fd fd fd fd fd fd
    0x0c567fff85a0: fd fd fd fd fd fd fd fd fd fd fd fd fd fd fd fd
    0x0c567fff85b0: fd fd fd fd fd fd fd fd fd fd fd fd fd fd fd fd
  =>0x0c567fff85c0: fd fd fd fd fd fd fd[fd]fd fd fd fd fd fd fd fd
    0x0c567fff85d0: fd fd fd fd fd fd fd fd fd fd fd fd fd fd fd fd
    0x0c567fff85e0: fd fd fd fd fd fd fd fd fd fd fd fd fd fd fd fd
    0x0c567fff85f0: fd fd fd fd fd fd fd fd fd fd fd fd fd fd fd fd
    0x0c567fff8600: fd fd fd fd fd fd fd fd fd fd fd fd fd fd fd fd
    0x0c567fff8610: fd fd fd fd fd fd fd fd fd fd fd fd fd fd fd fd
  Shadow byte legend (one shadow byte represents 8 application bytes):
    Addressable:           00
    Partially addressable: 01 02 03 04 05 06 07
    Heap left redzone:       fa
    Freed heap region:       fd
    Stack left redzone:      f1
    Stack mid redzone:       f2
    Stack right redzone:     f3
    Stack after return:      f5
    Stack use after scope:   f8
    Global redzone:          f9
    Global init order:       f6
    Poisoned by user:        f7
    Container overflow:      fc
    Array cookie:            ac
    Intra object redzone:    bb
    ASan internal:           fe
    Left alloca redzone:     ca
    Right alloca redzone:    cb
  ==27350==ABORTING

Signed-off-by: Changbin Du <changbin.du@gmail.com>
Reviewed-by: Jiri Olsa <jolsa@kernel.org>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt (VMware) <rostedt@goodmis.org>
Link: http://lkml.kernel.org/r/20190316080556.3075-8-changbin.du@gmail.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
randomhydrosol pushed a commit to randomhydrosol/linux-hardened that referenced this issue Mar 27, 2019
Using gcc's ASan, Changbin reports:

  =================================================================
  ==7494==ERROR: LeakSanitizer: detected memory leaks

  Direct leak of 48 byte(s) in 1 object(s) allocated from:
      #0 0x7f0333a89138 in calloc (/usr/lib/x86_64-linux-gnu/libasan.so.5+0xee138)
      GrapheneOS#1 0x5625e5330a5e in zalloc util/util.h:23
      GrapheneOS#2 0x5625e5330a9b in perf_counts__new util/counts.c:10
      GrapheneOS#3 0x5625e5330ca0 in perf_evsel__alloc_counts util/counts.c:47
      GrapheneOS#4 0x5625e520d8e5 in __perf_evsel__read_on_cpu util/evsel.c:1505
      GrapheneOS#5 0x5625e517a985 in perf_evsel__read_on_cpu /home/work/linux/tools/perf/util/evsel.h:347
      GrapheneOS#6 0x5625e517ad1a in test__openat_syscall_event tests/openat-syscall.c:47
      GrapheneOS#7 0x5625e51528e6 in run_test tests/builtin-test.c:358
      GrapheneOS#8 0x5625e5152baf in test_and_print tests/builtin-test.c:388
      GrapheneOS#9 0x5625e51543fe in __cmd_test tests/builtin-test.c:583
      GrapheneOS#10 0x5625e515572f in cmd_test tests/builtin-test.c:722
      GrapheneOS#11 0x5625e51c3fb8 in run_builtin /home/changbin/work/linux/tools/perf/perf.c:302
      GrapheneOS#12 0x5625e51c44f7 in handle_internal_command /home/changbin/work/linux/tools/perf/perf.c:354
      GrapheneOS#13 0x5625e51c48fb in run_argv /home/changbin/work/linux/tools/perf/perf.c:398
      GrapheneOS#14 0x5625e51c5069 in main /home/changbin/work/linux/tools/perf/perf.c:520
      GrapheneOS#15 0x7f033214d09a in __libc_start_main (/lib/x86_64-linux-gnu/libc.so.6+0x2409a)

  Indirect leak of 72 byte(s) in 1 object(s) allocated from:
      #0 0x7f0333a89138 in calloc (/usr/lib/x86_64-linux-gnu/libasan.so.5+0xee138)
      GrapheneOS#1 0x5625e532560d in zalloc util/util.h:23
      GrapheneOS#2 0x5625e532566b in xyarray__new util/xyarray.c:10
      GrapheneOS#3 0x5625e5330aba in perf_counts__new util/counts.c:15
      GrapheneOS#4 0x5625e5330ca0 in perf_evsel__alloc_counts util/counts.c:47
      GrapheneOS#5 0x5625e520d8e5 in __perf_evsel__read_on_cpu util/evsel.c:1505
      GrapheneOS#6 0x5625e517a985 in perf_evsel__read_on_cpu /home/work/linux/tools/perf/util/evsel.h:347
      GrapheneOS#7 0x5625e517ad1a in test__openat_syscall_event tests/openat-syscall.c:47
      GrapheneOS#8 0x5625e51528e6 in run_test tests/builtin-test.c:358
      GrapheneOS#9 0x5625e5152baf in test_and_print tests/builtin-test.c:388
      GrapheneOS#10 0x5625e51543fe in __cmd_test tests/builtin-test.c:583
      GrapheneOS#11 0x5625e515572f in cmd_test tests/builtin-test.c:722
      GrapheneOS#12 0x5625e51c3fb8 in run_builtin /home/changbin/work/linux/tools/perf/perf.c:302
      GrapheneOS#13 0x5625e51c44f7 in handle_internal_command /home/changbin/work/linux/tools/perf/perf.c:354
      GrapheneOS#14 0x5625e51c48fb in run_argv /home/changbin/work/linux/tools/perf/perf.c:398
      GrapheneOS#15 0x5625e51c5069 in main /home/changbin/work/linux/tools/perf/perf.c:520
      GrapheneOS#16 0x7f033214d09a in __libc_start_main (/lib/x86_64-linux-gnu/libc.so.6+0x2409a)

His patch took care of evsel->prev_raw_counts, but the above backtraces
are about evsel->counts, so fix that instead.

Reported-by: Changbin Du <changbin.du@gmail.com>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt (VMware) <rostedt@goodmis.org>
Link: https://lkml.kernel.org/n/tip-hd1x13g59f0nuhe4anxhsmfp@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
randomhydrosol pushed a commit to randomhydrosol/linux-hardened that referenced this issue Mar 27, 2019
…_event_on_all_cpus test

  =================================================================
  ==7497==ERROR: LeakSanitizer: detected memory leaks

  Direct leak of 40 byte(s) in 1 object(s) allocated from:
      #0 0x7f0333a88f30 in __interceptor_malloc (/usr/lib/x86_64-linux-gnu/libasan.so.5+0xedf30)
      GrapheneOS#1 0x5625e5326213 in cpu_map__trim_new util/cpumap.c:45
      GrapheneOS#2 0x5625e5326703 in cpu_map__read util/cpumap.c:103
      GrapheneOS#3 0x5625e53267ef in cpu_map__read_all_cpu_map util/cpumap.c:120
      GrapheneOS#4 0x5625e5326915 in cpu_map__new util/cpumap.c:135
      GrapheneOS#5 0x5625e517b355 in test__openat_syscall_event_on_all_cpus tests/openat-syscall-all-cpus.c:36
      GrapheneOS#6 0x5625e51528e6 in run_test tests/builtin-test.c:358
      GrapheneOS#7 0x5625e5152baf in test_and_print tests/builtin-test.c:388
      GrapheneOS#8 0x5625e51543fe in __cmd_test tests/builtin-test.c:583
      GrapheneOS#9 0x5625e515572f in cmd_test tests/builtin-test.c:722
      GrapheneOS#10 0x5625e51c3fb8 in run_builtin /home/changbin/work/linux/tools/perf/perf.c:302
      GrapheneOS#11 0x5625e51c44f7 in handle_internal_command /home/changbin/work/linux/tools/perf/perf.c:354
      GrapheneOS#12 0x5625e51c48fb in run_argv /home/changbin/work/linux/tools/perf/perf.c:398
      GrapheneOS#13 0x5625e51c5069 in main /home/changbin/work/linux/tools/perf/perf.c:520
      GrapheneOS#14 0x7f033214d09a in __libc_start_main (/lib/x86_64-linux-gnu/libc.so.6+0x2409a)

Signed-off-by: Changbin Du <changbin.du@gmail.com>
Reviewed-by: Jiri Olsa <jolsa@kernel.org>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt (VMware) <rostedt@goodmis.org>
Fixes: f30a79b ("perf tools: Add reference counting for cpu_map object")
Link: http://lkml.kernel.org/r/20190316080556.3075-15-changbin.du@gmail.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
randomhydrosol pushed a commit to randomhydrosol/linux-hardened that referenced this issue Mar 27, 2019
  =================================================================
  ==20875==ERROR: LeakSanitizer: detected memory leaks

  Direct leak of 1160 byte(s) in 1 object(s) allocated from:
      #0 0x7f1b6fc84138 in calloc (/usr/lib/x86_64-linux-gnu/libasan.so.5+0xee138)
      GrapheneOS#1 0x55bd50005599 in zalloc util/util.h:23
      GrapheneOS#2 0x55bd500068f5 in perf_evsel__newtp_idx util/evsel.c:327
      GrapheneOS#3 0x55bd4ff810fc in perf_evsel__newtp /home/work/linux/tools/perf/util/evsel.h:216
      GrapheneOS#4 0x55bd4ff81608 in test__perf_evsel__tp_sched_test tests/evsel-tp-sched.c:69
      GrapheneOS#5 0x55bd4ff528e6 in run_test tests/builtin-test.c:358
      GrapheneOS#6 0x55bd4ff52baf in test_and_print tests/builtin-test.c:388
      GrapheneOS#7 0x55bd4ff543fe in __cmd_test tests/builtin-test.c:583
      GrapheneOS#8 0x55bd4ff5572f in cmd_test tests/builtin-test.c:722
      GrapheneOS#9 0x55bd4ffc4087 in run_builtin /home/changbin/work/linux/tools/perf/perf.c:302
      GrapheneOS#10 0x55bd4ffc45c6 in handle_internal_command /home/changbin/work/linux/tools/perf/perf.c:354
      GrapheneOS#11 0x55bd4ffc49ca in run_argv /home/changbin/work/linux/tools/perf/perf.c:398
      GrapheneOS#12 0x55bd4ffc5138 in main /home/changbin/work/linux/tools/perf/perf.c:520
      GrapheneOS#13 0x7f1b6e34809a in __libc_start_main (/lib/x86_64-linux-gnu/libc.so.6+0x2409a)

  Indirect leak of 19 byte(s) in 1 object(s) allocated from:
      #0 0x7f1b6fc83f30 in __interceptor_malloc (/usr/lib/x86_64-linux-gnu/libasan.so.5+0xedf30)
      GrapheneOS#1 0x7f1b6e3ac30f in vasprintf (/lib/x86_64-linux-gnu/libc.so.6+0x8830f)

Signed-off-by: Changbin Du <changbin.du@gmail.com>
Reviewed-by: Jiri Olsa <jolsa@kernel.org>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt (VMware) <rostedt@goodmis.org>
Fixes: 6a6cd11 ("perf test: Add test for the sched tracepoint format fields")
Link: http://lkml.kernel.org/r/20190316080556.3075-17-changbin.du@gmail.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
randomhydrosol pushed a commit to randomhydrosol/linux-hardened that referenced this issue Apr 19, 2019
The spinlock in the raw3270_view structure is used by con3270, tty3270
and fs3270 in different ways. For con3270 the lock can be acquired in
irq context, for tty3270 and fs3270 the highest context is bh.

Lockdep sees the view->lock as a single class and if the 3270 driver
is used for the console the following message is generated:

WARNING: inconsistent lock state
5.1.0-rc3-05157-g5c168033979d GrapheneOS#12 Not tainted
--------------------------------
inconsistent {IN-HARDIRQ-W} -> {HARDIRQ-ON-W} usage.
swapper/0/1 [HC0[0]:SC1[1]:HE1:SE0] takes:
(____ptrval____) (&(&view->lock)->rlock){?.-.}, at: tty3270_update+0x7c/0x330

Introduce a lockdep subclass for the view lock to distinguish bh from
irq locks.

Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
randomhydrosol pushed a commit to randomhydrosol/linux-hardened that referenced this issue Apr 22, 2019
By calling maps__insert() we assume to get 2 references on the map,
which we relese within maps__remove call.

However if there's already same map name, we currently don't bump the
reference and can crash, like:

  Program received signal SIGABRT, Aborted.
  0x00007ffff75e60f5 in raise () from /lib64/libc.so.6

  (gdb) bt
  #0  0x00007ffff75e60f5 in raise () from /lib64/libc.so.6
  GrapheneOS#1  0x00007ffff75d0895 in abort () from /lib64/libc.so.6
  GrapheneOS#2  0x00007ffff75d0769 in __assert_fail_base.cold () from /lib64/libc.so.6
  GrapheneOS#3  0x00007ffff75de596 in __assert_fail () from /lib64/libc.so.6
  GrapheneOS#4  0x00000000004fc006 in refcount_sub_and_test (i=1, r=0x1224e88) at tools/include/linux/refcount.h:131
  GrapheneOS#5  refcount_dec_and_test (r=0x1224e88) at tools/include/linux/refcount.h:148
  GrapheneOS#6  map__put (map=0x1224df0) at util/map.c:299
  GrapheneOS#7  0x00000000004fdb95 in __maps__remove (map=0x1224df0, maps=0xb17d80) at util/map.c:953
  GrapheneOS#8  maps__remove (maps=0xb17d80, map=0x1224df0) at util/map.c:959
  GrapheneOS#9  0x00000000004f7d8a in map_groups__remove (map=<optimized out>, mg=<optimized out>) at util/map_groups.h:65
  GrapheneOS#10 machine__process_ksymbol_unregister (sample=<optimized out>, event=0x7ffff7279670, machine=<optimized out>) at util/machine.c:728
  GrapheneOS#11 machine__process_ksymbol (machine=<optimized out>, event=0x7ffff7279670, sample=<optimized out>) at util/machine.c:741
  GrapheneOS#12 0x00000000004fffbb in perf_session__deliver_event (session=0xb11390, event=0x7ffff7279670, tool=0x7fffffffc7b0, file_offset=13936) at util/session.c:1362
  GrapheneOS#13 0x00000000005039bb in do_flush (show_progress=false, oe=0xb17e80) at util/ordered-events.c:243
  GrapheneOS#14 __ordered_events__flush (oe=0xb17e80, how=OE_FLUSH__ROUND, timestamp=<optimized out>) at util/ordered-events.c:322
  GrapheneOS#15 0x00000000005005e4 in perf_session__process_user_event (session=session@entry=0xb11390, event=event@entry=0x7ffff72a4af8,
  ...

Add the map to the list and getting the reference event if we find the
map with same name.

Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: Eric Saint-Etienne <eric.saint.etienne@oracle.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Song Liu <songliubraving@fb.com>
Fixes: 1e62856 ("perf symbols: Fix slowness due to -ffunction-section")
Link: http://lkml.kernel.org/r/20190416160127.30203-10-jolsa@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
anthraxx referenced this issue in anthraxx/linux-hardened May 1, 2019
[ Upstream commit 42dfa45 ]

Using gcc's ASan, Changbin reports:

  =================================================================
  ==7494==ERROR: LeakSanitizer: detected memory leaks

  Direct leak of 48 byte(s) in 1 object(s) allocated from:
      #0 0x7f0333a89138 in calloc (/usr/lib/x86_64-linux-gnu/libasan.so.5+0xee138)
      #1 0x5625e5330a5e in zalloc util/util.h:23
      #2 0x5625e5330a9b in perf_counts__new util/counts.c:10
      #3 0x5625e5330ca0 in perf_evsel__alloc_counts util/counts.c:47
      #4 0x5625e520d8e5 in __perf_evsel__read_on_cpu util/evsel.c:1505
      #5 0x5625e517a985 in perf_evsel__read_on_cpu /home/work/linux/tools/perf/util/evsel.h:347
      #6 0x5625e517ad1a in test__openat_syscall_event tests/openat-syscall.c:47
      #7 0x5625e51528e6 in run_test tests/builtin-test.c:358
      #8 0x5625e5152baf in test_and_print tests/builtin-test.c:388
      #9 0x5625e51543fe in __cmd_test tests/builtin-test.c:583
      #10 0x5625e515572f in cmd_test tests/builtin-test.c:722
      #11 0x5625e51c3fb8 in run_builtin /home/changbin/work/linux/tools/perf/perf.c:302
      #12 0x5625e51c44f7 in handle_internal_command /home/changbin/work/linux/tools/perf/perf.c:354
      #13 0x5625e51c48fb in run_argv /home/changbin/work/linux/tools/perf/perf.c:398
      #14 0x5625e51c5069 in main /home/changbin/work/linux/tools/perf/perf.c:520
      #15 0x7f033214d09a in __libc_start_main (/lib/x86_64-linux-gnu/libc.so.6+0x2409a)

  Indirect leak of 72 byte(s) in 1 object(s) allocated from:
      #0 0x7f0333a89138 in calloc (/usr/lib/x86_64-linux-gnu/libasan.so.5+0xee138)
      #1 0x5625e532560d in zalloc util/util.h:23
      #2 0x5625e532566b in xyarray__new util/xyarray.c:10
      #3 0x5625e5330aba in perf_counts__new util/counts.c:15
      #4 0x5625e5330ca0 in perf_evsel__alloc_counts util/counts.c:47
      #5 0x5625e520d8e5 in __perf_evsel__read_on_cpu util/evsel.c:1505
      #6 0x5625e517a985 in perf_evsel__read_on_cpu /home/work/linux/tools/perf/util/evsel.h:347
      #7 0x5625e517ad1a in test__openat_syscall_event tests/openat-syscall.c:47
      #8 0x5625e51528e6 in run_test tests/builtin-test.c:358
      #9 0x5625e5152baf in test_and_print tests/builtin-test.c:388
      #10 0x5625e51543fe in __cmd_test tests/builtin-test.c:583
      #11 0x5625e515572f in cmd_test tests/builtin-test.c:722
      #12 0x5625e51c3fb8 in run_builtin /home/changbin/work/linux/tools/perf/perf.c:302
      #13 0x5625e51c44f7 in handle_internal_command /home/changbin/work/linux/tools/perf/perf.c:354
      #14 0x5625e51c48fb in run_argv /home/changbin/work/linux/tools/perf/perf.c:398
      #15 0x5625e51c5069 in main /home/changbin/work/linux/tools/perf/perf.c:520
      #16 0x7f033214d09a in __libc_start_main (/lib/x86_64-linux-gnu/libc.so.6+0x2409a)

His patch took care of evsel->prev_raw_counts, but the above backtraces
are about evsel->counts, so fix that instead.

Reported-by: Changbin Du <changbin.du@gmail.com>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt (VMware) <rostedt@goodmis.org>
Link: https://lkml.kernel.org/n/tip-hd1x13g59f0nuhe4anxhsmfp@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
anthraxx referenced this issue in anthraxx/linux-hardened May 1, 2019
…_event_on_all_cpus test

[ Upstream commit 93faa52 ]

  =================================================================
  ==7497==ERROR: LeakSanitizer: detected memory leaks

  Direct leak of 40 byte(s) in 1 object(s) allocated from:
      #0 0x7f0333a88f30 in __interceptor_malloc (/usr/lib/x86_64-linux-gnu/libasan.so.5+0xedf30)
      #1 0x5625e5326213 in cpu_map__trim_new util/cpumap.c:45
      #2 0x5625e5326703 in cpu_map__read util/cpumap.c:103
      #3 0x5625e53267ef in cpu_map__read_all_cpu_map util/cpumap.c:120
      #4 0x5625e5326915 in cpu_map__new util/cpumap.c:135
      #5 0x5625e517b355 in test__openat_syscall_event_on_all_cpus tests/openat-syscall-all-cpus.c:36
      #6 0x5625e51528e6 in run_test tests/builtin-test.c:358
      #7 0x5625e5152baf in test_and_print tests/builtin-test.c:388
      #8 0x5625e51543fe in __cmd_test tests/builtin-test.c:583
      #9 0x5625e515572f in cmd_test tests/builtin-test.c:722
      #10 0x5625e51c3fb8 in run_builtin /home/changbin/work/linux/tools/perf/perf.c:302
      #11 0x5625e51c44f7 in handle_internal_command /home/changbin/work/linux/tools/perf/perf.c:354
      #12 0x5625e51c48fb in run_argv /home/changbin/work/linux/tools/perf/perf.c:398
      #13 0x5625e51c5069 in main /home/changbin/work/linux/tools/perf/perf.c:520
      #14 0x7f033214d09a in __libc_start_main (/lib/x86_64-linux-gnu/libc.so.6+0x2409a)

Signed-off-by: Changbin Du <changbin.du@gmail.com>
Reviewed-by: Jiri Olsa <jolsa@kernel.org>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt (VMware) <rostedt@goodmis.org>
Fixes: f30a79b ("perf tools: Add reference counting for cpu_map object")
Link: http://lkml.kernel.org/r/20190316080556.3075-15-changbin.du@gmail.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
anthraxx referenced this issue in anthraxx/linux-hardened May 1, 2019
[ Upstream commit d982b33 ]

  =================================================================
  ==20875==ERROR: LeakSanitizer: detected memory leaks

  Direct leak of 1160 byte(s) in 1 object(s) allocated from:
      #0 0x7f1b6fc84138 in calloc (/usr/lib/x86_64-linux-gnu/libasan.so.5+0xee138)
      #1 0x55bd50005599 in zalloc util/util.h:23
      #2 0x55bd500068f5 in perf_evsel__newtp_idx util/evsel.c:327
      #3 0x55bd4ff810fc in perf_evsel__newtp /home/work/linux/tools/perf/util/evsel.h:216
      #4 0x55bd4ff81608 in test__perf_evsel__tp_sched_test tests/evsel-tp-sched.c:69
      #5 0x55bd4ff528e6 in run_test tests/builtin-test.c:358
      #6 0x55bd4ff52baf in test_and_print tests/builtin-test.c:388
      #7 0x55bd4ff543fe in __cmd_test tests/builtin-test.c:583
      #8 0x55bd4ff5572f in cmd_test tests/builtin-test.c:722
      #9 0x55bd4ffc4087 in run_builtin /home/changbin/work/linux/tools/perf/perf.c:302
      #10 0x55bd4ffc45c6 in handle_internal_command /home/changbin/work/linux/tools/perf/perf.c:354
      #11 0x55bd4ffc49ca in run_argv /home/changbin/work/linux/tools/perf/perf.c:398
      #12 0x55bd4ffc5138 in main /home/changbin/work/linux/tools/perf/perf.c:520
      #13 0x7f1b6e34809a in __libc_start_main (/lib/x86_64-linux-gnu/libc.so.6+0x2409a)

  Indirect leak of 19 byte(s) in 1 object(s) allocated from:
      #0 0x7f1b6fc83f30 in __interceptor_malloc (/usr/lib/x86_64-linux-gnu/libasan.so.5+0xedf30)
      #1 0x7f1b6e3ac30f in vasprintf (/lib/x86_64-linux-gnu/libc.so.6+0x8830f)

Signed-off-by: Changbin Du <changbin.du@gmail.com>
Reviewed-by: Jiri Olsa <jolsa@kernel.org>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt (VMware) <rostedt@goodmis.org>
Fixes: 6a6cd11 ("perf test: Add test for the sched tracepoint format fields")
Link: http://lkml.kernel.org/r/20190316080556.3075-17-changbin.du@gmail.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
anthraxx referenced this issue in anthraxx/linux-hardened May 1, 2019
[ Upstream commit 42dfa45 ]

Using gcc's ASan, Changbin reports:

  =================================================================
  ==7494==ERROR: LeakSanitizer: detected memory leaks

  Direct leak of 48 byte(s) in 1 object(s) allocated from:
      #0 0x7f0333a89138 in calloc (/usr/lib/x86_64-linux-gnu/libasan.so.5+0xee138)
      #1 0x5625e5330a5e in zalloc util/util.h:23
      #2 0x5625e5330a9b in perf_counts__new util/counts.c:10
      #3 0x5625e5330ca0 in perf_evsel__alloc_counts util/counts.c:47
      #4 0x5625e520d8e5 in __perf_evsel__read_on_cpu util/evsel.c:1505
      #5 0x5625e517a985 in perf_evsel__read_on_cpu /home/work/linux/tools/perf/util/evsel.h:347
      #6 0x5625e517ad1a in test__openat_syscall_event tests/openat-syscall.c:47
      #7 0x5625e51528e6 in run_test tests/builtin-test.c:358
      #8 0x5625e5152baf in test_and_print tests/builtin-test.c:388
      #9 0x5625e51543fe in __cmd_test tests/builtin-test.c:583
      #10 0x5625e515572f in cmd_test tests/builtin-test.c:722
      #11 0x5625e51c3fb8 in run_builtin /home/changbin/work/linux/tools/perf/perf.c:302
      #12 0x5625e51c44f7 in handle_internal_command /home/changbin/work/linux/tools/perf/perf.c:354
      #13 0x5625e51c48fb in run_argv /home/changbin/work/linux/tools/perf/perf.c:398
      #14 0x5625e51c5069 in main /home/changbin/work/linux/tools/perf/perf.c:520
      #15 0x7f033214d09a in __libc_start_main (/lib/x86_64-linux-gnu/libc.so.6+0x2409a)

  Indirect leak of 72 byte(s) in 1 object(s) allocated from:
      #0 0x7f0333a89138 in calloc (/usr/lib/x86_64-linux-gnu/libasan.so.5+0xee138)
      #1 0x5625e532560d in zalloc util/util.h:23
      #2 0x5625e532566b in xyarray__new util/xyarray.c:10
      #3 0x5625e5330aba in perf_counts__new util/counts.c:15
      #4 0x5625e5330ca0 in perf_evsel__alloc_counts util/counts.c:47
      #5 0x5625e520d8e5 in __perf_evsel__read_on_cpu util/evsel.c:1505
      #6 0x5625e517a985 in perf_evsel__read_on_cpu /home/work/linux/tools/perf/util/evsel.h:347
      #7 0x5625e517ad1a in test__openat_syscall_event tests/openat-syscall.c:47
      #8 0x5625e51528e6 in run_test tests/builtin-test.c:358
      #9 0x5625e5152baf in test_and_print tests/builtin-test.c:388
      #10 0x5625e51543fe in __cmd_test tests/builtin-test.c:583
      #11 0x5625e515572f in cmd_test tests/builtin-test.c:722
      #12 0x5625e51c3fb8 in run_builtin /home/changbin/work/linux/tools/perf/perf.c:302
      #13 0x5625e51c44f7 in handle_internal_command /home/changbin/work/linux/tools/perf/perf.c:354
      #14 0x5625e51c48fb in run_argv /home/changbin/work/linux/tools/perf/perf.c:398
      #15 0x5625e51c5069 in main /home/changbin/work/linux/tools/perf/perf.c:520
      #16 0x7f033214d09a in __libc_start_main (/lib/x86_64-linux-gnu/libc.so.6+0x2409a)

His patch took care of evsel->prev_raw_counts, but the above backtraces
are about evsel->counts, so fix that instead.

Reported-by: Changbin Du <changbin.du@gmail.com>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt (VMware) <rostedt@goodmis.org>
Link: https://lkml.kernel.org/n/tip-hd1x13g59f0nuhe4anxhsmfp@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
anthraxx referenced this issue in anthraxx/linux-hardened May 1, 2019
…_event_on_all_cpus test

[ Upstream commit 93faa52 ]

  =================================================================
  ==7497==ERROR: LeakSanitizer: detected memory leaks

  Direct leak of 40 byte(s) in 1 object(s) allocated from:
      #0 0x7f0333a88f30 in __interceptor_malloc (/usr/lib/x86_64-linux-gnu/libasan.so.5+0xedf30)
      #1 0x5625e5326213 in cpu_map__trim_new util/cpumap.c:45
      #2 0x5625e5326703 in cpu_map__read util/cpumap.c:103
      #3 0x5625e53267ef in cpu_map__read_all_cpu_map util/cpumap.c:120
      #4 0x5625e5326915 in cpu_map__new util/cpumap.c:135
      #5 0x5625e517b355 in test__openat_syscall_event_on_all_cpus tests/openat-syscall-all-cpus.c:36
      #6 0x5625e51528e6 in run_test tests/builtin-test.c:358
      #7 0x5625e5152baf in test_and_print tests/builtin-test.c:388
      #8 0x5625e51543fe in __cmd_test tests/builtin-test.c:583
      #9 0x5625e515572f in cmd_test tests/builtin-test.c:722
      #10 0x5625e51c3fb8 in run_builtin /home/changbin/work/linux/tools/perf/perf.c:302
      #11 0x5625e51c44f7 in handle_internal_command /home/changbin/work/linux/tools/perf/perf.c:354
      #12 0x5625e51c48fb in run_argv /home/changbin/work/linux/tools/perf/perf.c:398
      #13 0x5625e51c5069 in main /home/changbin/work/linux/tools/perf/perf.c:520
      #14 0x7f033214d09a in __libc_start_main (/lib/x86_64-linux-gnu/libc.so.6+0x2409a)

Signed-off-by: Changbin Du <changbin.du@gmail.com>
Reviewed-by: Jiri Olsa <jolsa@kernel.org>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt (VMware) <rostedt@goodmis.org>
Fixes: f30a79b ("perf tools: Add reference counting for cpu_map object")
Link: http://lkml.kernel.org/r/20190316080556.3075-15-changbin.du@gmail.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
anthraxx referenced this issue in anthraxx/linux-hardened May 1, 2019
[ Upstream commit d982b33 ]

  =================================================================
  ==20875==ERROR: LeakSanitizer: detected memory leaks

  Direct leak of 1160 byte(s) in 1 object(s) allocated from:
      #0 0x7f1b6fc84138 in calloc (/usr/lib/x86_64-linux-gnu/libasan.so.5+0xee138)
      #1 0x55bd50005599 in zalloc util/util.h:23
      #2 0x55bd500068f5 in perf_evsel__newtp_idx util/evsel.c:327
      #3 0x55bd4ff810fc in perf_evsel__newtp /home/work/linux/tools/perf/util/evsel.h:216
      #4 0x55bd4ff81608 in test__perf_evsel__tp_sched_test tests/evsel-tp-sched.c:69
      #5 0x55bd4ff528e6 in run_test tests/builtin-test.c:358
      #6 0x55bd4ff52baf in test_and_print tests/builtin-test.c:388
      #7 0x55bd4ff543fe in __cmd_test tests/builtin-test.c:583
      #8 0x55bd4ff5572f in cmd_test tests/builtin-test.c:722
      #9 0x55bd4ffc4087 in run_builtin /home/changbin/work/linux/tools/perf/perf.c:302
      #10 0x55bd4ffc45c6 in handle_internal_command /home/changbin/work/linux/tools/perf/perf.c:354
      #11 0x55bd4ffc49ca in run_argv /home/changbin/work/linux/tools/perf/perf.c:398
      #12 0x55bd4ffc5138 in main /home/changbin/work/linux/tools/perf/perf.c:520
      #13 0x7f1b6e34809a in __libc_start_main (/lib/x86_64-linux-gnu/libc.so.6+0x2409a)

  Indirect leak of 19 byte(s) in 1 object(s) allocated from:
      #0 0x7f1b6fc83f30 in __interceptor_malloc (/usr/lib/x86_64-linux-gnu/libasan.so.5+0xedf30)
      #1 0x7f1b6e3ac30f in vasprintf (/lib/x86_64-linux-gnu/libc.so.6+0x8830f)

Signed-off-by: Changbin Du <changbin.du@gmail.com>
Reviewed-by: Jiri Olsa <jolsa@kernel.org>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt (VMware) <rostedt@goodmis.org>
Fixes: 6a6cd11 ("perf test: Add test for the sched tracepoint format fields")
Link: http://lkml.kernel.org/r/20190316080556.3075-17-changbin.du@gmail.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
anthraxx referenced this issue in anthraxx/linux-hardened May 20, 2019
[ Upstream commit 5712f33 ]

The spinlock in the raw3270_view structure is used by con3270, tty3270
and fs3270 in different ways. For con3270 the lock can be acquired in
irq context, for tty3270 and fs3270 the highest context is bh.

Lockdep sees the view->lock as a single class and if the 3270 driver
is used for the console the following message is generated:

WARNING: inconsistent lock state
5.1.0-rc3-05157-g5c168033979d #12 Not tainted
--------------------------------
inconsistent {IN-HARDIRQ-W} -> {HARDIRQ-ON-W} usage.
swapper/0/1 [HC0[0]:SC1[1]:HE1:SE0] takes:
(____ptrval____) (&(&view->lock)->rlock){?.-.}, at: tty3270_update+0x7c/0x330

Introduce a lockdep subclass for the view lock to distinguish bh from
irq locks.

Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

Signed-off-by: Sasha Levin <sashal@kernel.org>
anthraxx referenced this issue in anthraxx/linux-hardened May 20, 2019
[ Upstream commit 5712f33 ]

The spinlock in the raw3270_view structure is used by con3270, tty3270
and fs3270 in different ways. For con3270 the lock can be acquired in
irq context, for tty3270 and fs3270 the highest context is bh.

Lockdep sees the view->lock as a single class and if the 3270 driver
is used for the console the following message is generated:

WARNING: inconsistent lock state
5.1.0-rc3-05157-g5c168033979d #12 Not tainted
--------------------------------
inconsistent {IN-HARDIRQ-W} -> {HARDIRQ-ON-W} usage.
swapper/0/1 [HC0[0]:SC1[1]:HE1:SE0] takes:
(____ptrval____) (&(&view->lock)->rlock){?.-.}, at: tty3270_update+0x7c/0x330

Introduce a lockdep subclass for the view lock to distinguish bh from
irq locks.

Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

Signed-off-by: Sasha Levin <sashal@kernel.org>
anthraxx referenced this issue in anthraxx/linux-hardened May 20, 2019
[ Upstream commit 5712f33 ]

The spinlock in the raw3270_view structure is used by con3270, tty3270
and fs3270 in different ways. For con3270 the lock can be acquired in
irq context, for tty3270 and fs3270 the highest context is bh.

Lockdep sees the view->lock as a single class and if the 3270 driver
is used for the console the following message is generated:

WARNING: inconsistent lock state
5.1.0-rc3-05157-g5c168033979d #12 Not tainted
--------------------------------
inconsistent {IN-HARDIRQ-W} -> {HARDIRQ-ON-W} usage.
swapper/0/1 [HC0[0]:SC1[1]:HE1:SE0] takes:
(____ptrval____) (&(&view->lock)->rlock){?.-.}, at: tty3270_update+0x7c/0x330

Introduce a lockdep subclass for the view lock to distinguish bh from
irq locks.

Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

Signed-off-by: Sasha Levin <sashal@kernel.org>
anthraxx referenced this issue in anthraxx/linux-hardened May 20, 2019
[ Upstream commit b9abbdf ]

By calling maps__insert() we assume to get 2 references on the map,
which we relese within maps__remove call.

However if there's already same map name, we currently don't bump the
reference and can crash, like:

  Program received signal SIGABRT, Aborted.
  0x00007ffff75e60f5 in raise () from /lib64/libc.so.6

  (gdb) bt
  #0  0x00007ffff75e60f5 in raise () from /lib64/libc.so.6
  #1  0x00007ffff75d0895 in abort () from /lib64/libc.so.6
  #2  0x00007ffff75d0769 in __assert_fail_base.cold () from /lib64/libc.so.6
  #3  0x00007ffff75de596 in __assert_fail () from /lib64/libc.so.6
  #4  0x00000000004fc006 in refcount_sub_and_test (i=1, r=0x1224e88) at tools/include/linux/refcount.h:131
  #5  refcount_dec_and_test (r=0x1224e88) at tools/include/linux/refcount.h:148
  #6  map__put (map=0x1224df0) at util/map.c:299
  #7  0x00000000004fdb95 in __maps__remove (map=0x1224df0, maps=0xb17d80) at util/map.c:953
  #8  maps__remove (maps=0xb17d80, map=0x1224df0) at util/map.c:959
  #9  0x00000000004f7d8a in map_groups__remove (map=<optimized out>, mg=<optimized out>) at util/map_groups.h:65
  #10 machine__process_ksymbol_unregister (sample=<optimized out>, event=0x7ffff7279670, machine=<optimized out>) at util/machine.c:728
  #11 machine__process_ksymbol (machine=<optimized out>, event=0x7ffff7279670, sample=<optimized out>) at util/machine.c:741
  #12 0x00000000004fffbb in perf_session__deliver_event (session=0xb11390, event=0x7ffff7279670, tool=0x7fffffffc7b0, file_offset=13936) at util/session.c:1362
  #13 0x00000000005039bb in do_flush (show_progress=false, oe=0xb17e80) at util/ordered-events.c:243
  #14 __ordered_events__flush (oe=0xb17e80, how=OE_FLUSH__ROUND, timestamp=<optimized out>) at util/ordered-events.c:322
  #15 0x00000000005005e4 in perf_session__process_user_event (session=session@entry=0xb11390, event=event@entry=0x7ffff72a4af8,
  ...

Add the map to the list and getting the reference event if we find the
map with same name.

Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: Eric Saint-Etienne <eric.saint.etienne@oracle.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Song Liu <songliubraving@fb.com>
Fixes: 1e62856 ("perf symbols: Fix slowness due to -ffunction-section")
Link: http://lkml.kernel.org/r/20190416160127.30203-10-jolsa@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
anthraxx referenced this issue in anthraxx/linux-hardened Aug 17, 2019
commit d0a255e upstream.

A deadlock with this stacktrace was observed.

The loop thread does a GFP_KERNEL allocation, it calls into dm-bufio
shrinker and the shrinker depends on I/O completion in the dm-bufio
subsystem.

In order to fix the deadlock (and other similar ones), we set the flag
PF_MEMALLOC_NOIO at loop thread entry.

PID: 474    TASK: ffff8813e11f4600  CPU: 10  COMMAND: "kswapd0"
   #0 [ffff8813dedfb938] __schedule at ffffffff8173f405
   #1 [ffff8813dedfb990] schedule at ffffffff8173fa27
   #2 [ffff8813dedfb9b0] schedule_timeout at ffffffff81742fec
   #3 [ffff8813dedfba60] io_schedule_timeout at ffffffff8173f186
   #4 [ffff8813dedfbaa0] bit_wait_io at ffffffff8174034f
   #5 [ffff8813dedfbac0] __wait_on_bit at ffffffff8173fec8
   #6 [ffff8813dedfbb10] out_of_line_wait_on_bit at ffffffff8173ff81
   #7 [ffff8813dedfbb90] __make_buffer_clean at ffffffffa038736f [dm_bufio]
   #8 [ffff8813dedfbbb0] __try_evict_buffer at ffffffffa0387bb8 [dm_bufio]
   #9 [ffff8813dedfbbd0] dm_bufio_shrink_scan at ffffffffa0387cc3 [dm_bufio]
  #10 [ffff8813dedfbc40] shrink_slab at ffffffff811a87ce
  #11 [ffff8813dedfbd30] shrink_zone at ffffffff811ad778
  #12 [ffff8813dedfbdc0] kswapd at ffffffff811ae92f
  #13 [ffff8813dedfbec0] kthread at ffffffff810a8428
  #14 [ffff8813dedfbf50] ret_from_fork at ffffffff81745242

  PID: 14127  TASK: ffff881455749c00  CPU: 11  COMMAND: "loop1"
   #0 [ffff88272f5af228] __schedule at ffffffff8173f405
   #1 [ffff88272f5af280] schedule at ffffffff8173fa27
   #2 [ffff88272f5af2a0] schedule_preempt_disabled at ffffffff8173fd5e
   #3 [ffff88272f5af2b0] __mutex_lock_slowpath at ffffffff81741fb5
   #4 [ffff88272f5af330] mutex_lock at ffffffff81742133
   #5 [ffff88272f5af350] dm_bufio_shrink_count at ffffffffa03865f9 [dm_bufio]
   #6 [ffff88272f5af380] shrink_slab at ffffffff811a86bd
   #7 [ffff88272f5af470] shrink_zone at ffffffff811ad778
   #8 [ffff88272f5af500] do_try_to_free_pages at ffffffff811adb34
   #9 [ffff88272f5af590] try_to_free_pages at ffffffff811adef8
  #10 [ffff88272f5af610] __alloc_pages_nodemask at ffffffff811a09c3
  #11 [ffff88272f5af710] alloc_pages_current at ffffffff811e8b71
  #12 [ffff88272f5af760] new_slab at ffffffff811f4523
  #13 [ffff88272f5af7b0] __slab_alloc at ffffffff8173a1b5
  #14 [ffff88272f5af880] kmem_cache_alloc at ffffffff811f484b
  #15 [ffff88272f5af8d0] do_blockdev_direct_IO at ffffffff812535b3
  #16 [ffff88272f5afb00] __blockdev_direct_IO at ffffffff81255dc3
  #17 [ffff88272f5afb30] xfs_vm_direct_IO at ffffffffa01fe3fc [xfs]
  #18 [ffff88272f5afb90] generic_file_read_iter at ffffffff81198994
  #19 [ffff88272f5afc50] __dta_xfs_file_read_iter_2398 at ffffffffa020c970 [xfs]
  #20 [ffff88272f5afcc0] lo_rw_aio at ffffffffa0377042 [loop]
  #21 [ffff88272f5afd70] loop_queue_work at ffffffffa0377c3b [loop]
  #22 [ffff88272f5afe60] kthread_worker_fn at ffffffff810a8a0c
  #23 [ffff88272f5afec0] kthread at ffffffff810a8428
  #24 [ffff88272f5aff50] ret_from_fork at ffffffff81745242

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Cc: stable@vger.kernel.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
anthraxx referenced this issue in anthraxx/linux-hardened Aug 17, 2019
commit d0a255e upstream.

A deadlock with this stacktrace was observed.

The loop thread does a GFP_KERNEL allocation, it calls into dm-bufio
shrinker and the shrinker depends on I/O completion in the dm-bufio
subsystem.

In order to fix the deadlock (and other similar ones), we set the flag
PF_MEMALLOC_NOIO at loop thread entry.

PID: 474    TASK: ffff8813e11f4600  CPU: 10  COMMAND: "kswapd0"
   #0 [ffff8813dedfb938] __schedule at ffffffff8173f405
   #1 [ffff8813dedfb990] schedule at ffffffff8173fa27
   #2 [ffff8813dedfb9b0] schedule_timeout at ffffffff81742fec
   #3 [ffff8813dedfba60] io_schedule_timeout at ffffffff8173f186
   #4 [ffff8813dedfbaa0] bit_wait_io at ffffffff8174034f
   #5 [ffff8813dedfbac0] __wait_on_bit at ffffffff8173fec8
   #6 [ffff8813dedfbb10] out_of_line_wait_on_bit at ffffffff8173ff81
   #7 [ffff8813dedfbb90] __make_buffer_clean at ffffffffa038736f [dm_bufio]
   #8 [ffff8813dedfbbb0] __try_evict_buffer at ffffffffa0387bb8 [dm_bufio]
   #9 [ffff8813dedfbbd0] dm_bufio_shrink_scan at ffffffffa0387cc3 [dm_bufio]
  #10 [ffff8813dedfbc40] shrink_slab at ffffffff811a87ce
  #11 [ffff8813dedfbd30] shrink_zone at ffffffff811ad778
  #12 [ffff8813dedfbdc0] kswapd at ffffffff811ae92f
  #13 [ffff8813dedfbec0] kthread at ffffffff810a8428
  #14 [ffff8813dedfbf50] ret_from_fork at ffffffff81745242

  PID: 14127  TASK: ffff881455749c00  CPU: 11  COMMAND: "loop1"
   #0 [ffff88272f5af228] __schedule at ffffffff8173f405
   #1 [ffff88272f5af280] schedule at ffffffff8173fa27
   #2 [ffff88272f5af2a0] schedule_preempt_disabled at ffffffff8173fd5e
   #3 [ffff88272f5af2b0] __mutex_lock_slowpath at ffffffff81741fb5
   #4 [ffff88272f5af330] mutex_lock at ffffffff81742133
   #5 [ffff88272f5af350] dm_bufio_shrink_count at ffffffffa03865f9 [dm_bufio]
   #6 [ffff88272f5af380] shrink_slab at ffffffff811a86bd
   #7 [ffff88272f5af470] shrink_zone at ffffffff811ad778
   #8 [ffff88272f5af500] do_try_to_free_pages at ffffffff811adb34
   #9 [ffff88272f5af590] try_to_free_pages at ffffffff811adef8
  #10 [ffff88272f5af610] __alloc_pages_nodemask at ffffffff811a09c3
  #11 [ffff88272f5af710] alloc_pages_current at ffffffff811e8b71
  #12 [ffff88272f5af760] new_slab at ffffffff811f4523
  #13 [ffff88272f5af7b0] __slab_alloc at ffffffff8173a1b5
  #14 [ffff88272f5af880] kmem_cache_alloc at ffffffff811f484b
  #15 [ffff88272f5af8d0] do_blockdev_direct_IO at ffffffff812535b3
  #16 [ffff88272f5afb00] __blockdev_direct_IO at ffffffff81255dc3
  #17 [ffff88272f5afb30] xfs_vm_direct_IO at ffffffffa01fe3fc [xfs]
  #18 [ffff88272f5afb90] generic_file_read_iter at ffffffff81198994
  #19 [ffff88272f5afc50] __dta_xfs_file_read_iter_2398 at ffffffffa020c970 [xfs]
  #20 [ffff88272f5afcc0] lo_rw_aio at ffffffffa0377042 [loop]
  #21 [ffff88272f5afd70] loop_queue_work at ffffffffa0377c3b [loop]
  #22 [ffff88272f5afe60] kthread_worker_fn at ffffffff810a8a0c
  #23 [ffff88272f5afec0] kthread at ffffffff810a8428
  #24 [ffff88272f5aff50] ret_from_fork at ffffffff81745242

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Cc: stable@vger.kernel.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
anthraxx referenced this issue in anthraxx/linux-hardened Aug 17, 2019
commit d0a255e upstream.

A deadlock with this stacktrace was observed.

The loop thread does a GFP_KERNEL allocation, it calls into dm-bufio
shrinker and the shrinker depends on I/O completion in the dm-bufio
subsystem.

In order to fix the deadlock (and other similar ones), we set the flag
PF_MEMALLOC_NOIO at loop thread entry.

PID: 474    TASK: ffff8813e11f4600  CPU: 10  COMMAND: "kswapd0"
   #0 [ffff8813dedfb938] __schedule at ffffffff8173f405
   #1 [ffff8813dedfb990] schedule at ffffffff8173fa27
   #2 [ffff8813dedfb9b0] schedule_timeout at ffffffff81742fec
   #3 [ffff8813dedfba60] io_schedule_timeout at ffffffff8173f186
   #4 [ffff8813dedfbaa0] bit_wait_io at ffffffff8174034f
   #5 [ffff8813dedfbac0] __wait_on_bit at ffffffff8173fec8
   #6 [ffff8813dedfbb10] out_of_line_wait_on_bit at ffffffff8173ff81
   #7 [ffff8813dedfbb90] __make_buffer_clean at ffffffffa038736f [dm_bufio]
   #8 [ffff8813dedfbbb0] __try_evict_buffer at ffffffffa0387bb8 [dm_bufio]
   #9 [ffff8813dedfbbd0] dm_bufio_shrink_scan at ffffffffa0387cc3 [dm_bufio]
  #10 [ffff8813dedfbc40] shrink_slab at ffffffff811a87ce
  #11 [ffff8813dedfbd30] shrink_zone at ffffffff811ad778
  #12 [ffff8813dedfbdc0] kswapd at ffffffff811ae92f
  #13 [ffff8813dedfbec0] kthread at ffffffff810a8428
  #14 [ffff8813dedfbf50] ret_from_fork at ffffffff81745242

  PID: 14127  TASK: ffff881455749c00  CPU: 11  COMMAND: "loop1"
   #0 [ffff88272f5af228] __schedule at ffffffff8173f405
   #1 [ffff88272f5af280] schedule at ffffffff8173fa27
   #2 [ffff88272f5af2a0] schedule_preempt_disabled at ffffffff8173fd5e
   #3 [ffff88272f5af2b0] __mutex_lock_slowpath at ffffffff81741fb5
   #4 [ffff88272f5af330] mutex_lock at ffffffff81742133
   #5 [ffff88272f5af350] dm_bufio_shrink_count at ffffffffa03865f9 [dm_bufio]
   #6 [ffff88272f5af380] shrink_slab at ffffffff811a86bd
   #7 [ffff88272f5af470] shrink_zone at ffffffff811ad778
   #8 [ffff88272f5af500] do_try_to_free_pages at ffffffff811adb34
   #9 [ffff88272f5af590] try_to_free_pages at ffffffff811adef8
  #10 [ffff88272f5af610] __alloc_pages_nodemask at ffffffff811a09c3
  #11 [ffff88272f5af710] alloc_pages_current at ffffffff811e8b71
  #12 [ffff88272f5af760] new_slab at ffffffff811f4523
  #13 [ffff88272f5af7b0] __slab_alloc at ffffffff8173a1b5
  #14 [ffff88272f5af880] kmem_cache_alloc at ffffffff811f484b
  #15 [ffff88272f5af8d0] do_blockdev_direct_IO at ffffffff812535b3
  #16 [ffff88272f5afb00] __blockdev_direct_IO at ffffffff81255dc3
  #17 [ffff88272f5afb30] xfs_vm_direct_IO at ffffffffa01fe3fc [xfs]
  #18 [ffff88272f5afb90] generic_file_read_iter at ffffffff81198994
  #19 [ffff88272f5afc50] __dta_xfs_file_read_iter_2398 at ffffffffa020c970 [xfs]
  #20 [ffff88272f5afcc0] lo_rw_aio at ffffffffa0377042 [loop]
  #21 [ffff88272f5afd70] loop_queue_work at ffffffffa0377c3b [loop]
  #22 [ffff88272f5afe60] kthread_worker_fn at ffffffff810a8a0c
  #23 [ffff88272f5afec0] kthread at ffffffff810a8428
  #24 [ffff88272f5aff50] ret_from_fork at ffffffff81745242

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Cc: stable@vger.kernel.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
anthraxx referenced this issue in anthraxx/linux-hardened Sep 2, 2019
commit cf3591e upstream.

Revert the commit bd293d0. The proper
fix has been made available with commit d0a255e ("loop: set
PF_MEMALLOC_NOIO for the worker thread").

Note that the fix offered by commit bd293d0 doesn't really prevent
the deadlock from occuring - if we look at the stacktrace reported by
Junxiao Bi, we see that it hangs in bit_wait_io and not on the mutex -
i.e. it has already successfully taken the mutex. Changing the mutex
from mutex_lock to mutex_trylock won't help with deadlocks that happen
afterwards.

PID: 474    TASK: ffff8813e11f4600  CPU: 10  COMMAND: "kswapd0"
   #0 [ffff8813dedfb938] __schedule at ffffffff8173f405
   #1 [ffff8813dedfb990] schedule at ffffffff8173fa27
   #2 [ffff8813dedfb9b0] schedule_timeout at ffffffff81742fec
   #3 [ffff8813dedfba60] io_schedule_timeout at ffffffff8173f186
   #4 [ffff8813dedfbaa0] bit_wait_io at ffffffff8174034f
   #5 [ffff8813dedfbac0] __wait_on_bit at ffffffff8173fec8
   #6 [ffff8813dedfbb10] out_of_line_wait_on_bit at ffffffff8173ff81
   #7 [ffff8813dedfbb90] __make_buffer_clean at ffffffffa038736f [dm_bufio]
   #8 [ffff8813dedfbbb0] __try_evict_buffer at ffffffffa0387bb8 [dm_bufio]
   #9 [ffff8813dedfbbd0] dm_bufio_shrink_scan at ffffffffa0387cc3 [dm_bufio]
  #10 [ffff8813dedfbc40] shrink_slab at ffffffff811a87ce
  #11 [ffff8813dedfbd30] shrink_zone at ffffffff811ad778
  #12 [ffff8813dedfbdc0] kswapd at ffffffff811ae92f
  #13 [ffff8813dedfbec0] kthread at ffffffff810a8428
  #14 [ffff8813dedfbf50] ret_from_fork at ffffffff81745242

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Cc: stable@vger.kernel.org
Fixes: bd293d0 ("dm bufio: fix deadlock with loop device")
Depends-on: d0a255e ("loop: set PF_MEMALLOC_NOIO for the worker thread")
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
anthraxx referenced this issue in anthraxx/linux-hardened Sep 2, 2019
commit cf3591e upstream.

Revert the commit bd293d0. The proper
fix has been made available with commit d0a255e ("loop: set
PF_MEMALLOC_NOIO for the worker thread").

Note that the fix offered by commit bd293d0 doesn't really prevent
the deadlock from occuring - if we look at the stacktrace reported by
Junxiao Bi, we see that it hangs in bit_wait_io and not on the mutex -
i.e. it has already successfully taken the mutex. Changing the mutex
from mutex_lock to mutex_trylock won't help with deadlocks that happen
afterwards.

PID: 474    TASK: ffff8813e11f4600  CPU: 10  COMMAND: "kswapd0"
   #0 [ffff8813dedfb938] __schedule at ffffffff8173f405
   #1 [ffff8813dedfb990] schedule at ffffffff8173fa27
   #2 [ffff8813dedfb9b0] schedule_timeout at ffffffff81742fec
   #3 [ffff8813dedfba60] io_schedule_timeout at ffffffff8173f186
   #4 [ffff8813dedfbaa0] bit_wait_io at ffffffff8174034f
   #5 [ffff8813dedfbac0] __wait_on_bit at ffffffff8173fec8
   #6 [ffff8813dedfbb10] out_of_line_wait_on_bit at ffffffff8173ff81
   #7 [ffff8813dedfbb90] __make_buffer_clean at ffffffffa038736f [dm_bufio]
   #8 [ffff8813dedfbbb0] __try_evict_buffer at ffffffffa0387bb8 [dm_bufio]
   #9 [ffff8813dedfbbd0] dm_bufio_shrink_scan at ffffffffa0387cc3 [dm_bufio]
  #10 [ffff8813dedfbc40] shrink_slab at ffffffff811a87ce
  #11 [ffff8813dedfbd30] shrink_zone at ffffffff811ad778
  #12 [ffff8813dedfbdc0] kswapd at ffffffff811ae92f
  #13 [ffff8813dedfbec0] kthread at ffffffff810a8428
  #14 [ffff8813dedfbf50] ret_from_fork at ffffffff81745242

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Cc: stable@vger.kernel.org
Fixes: bd293d0 ("dm bufio: fix deadlock with loop device")
Depends-on: d0a255e ("loop: set PF_MEMALLOC_NOIO for the worker thread")
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
anthraxx referenced this issue in anthraxx/linux-hardened Sep 2, 2019
commit cf3591e upstream.

Revert the commit bd293d0. The proper
fix has been made available with commit d0a255e ("loop: set
PF_MEMALLOC_NOIO for the worker thread").

Note that the fix offered by commit bd293d0 doesn't really prevent
the deadlock from occuring - if we look at the stacktrace reported by
Junxiao Bi, we see that it hangs in bit_wait_io and not on the mutex -
i.e. it has already successfully taken the mutex. Changing the mutex
from mutex_lock to mutex_trylock won't help with deadlocks that happen
afterwards.

PID: 474    TASK: ffff8813e11f4600  CPU: 10  COMMAND: "kswapd0"
   #0 [ffff8813dedfb938] __schedule at ffffffff8173f405
   #1 [ffff8813dedfb990] schedule at ffffffff8173fa27
   #2 [ffff8813dedfb9b0] schedule_timeout at ffffffff81742fec
   #3 [ffff8813dedfba60] io_schedule_timeout at ffffffff8173f186
   #4 [ffff8813dedfbaa0] bit_wait_io at ffffffff8174034f
   #5 [ffff8813dedfbac0] __wait_on_bit at ffffffff8173fec8
   #6 [ffff8813dedfbb10] out_of_line_wait_on_bit at ffffffff8173ff81
   #7 [ffff8813dedfbb90] __make_buffer_clean at ffffffffa038736f [dm_bufio]
   #8 [ffff8813dedfbbb0] __try_evict_buffer at ffffffffa0387bb8 [dm_bufio]
   #9 [ffff8813dedfbbd0] dm_bufio_shrink_scan at ffffffffa0387cc3 [dm_bufio]
  #10 [ffff8813dedfbc40] shrink_slab at ffffffff811a87ce
  #11 [ffff8813dedfbd30] shrink_zone at ffffffff811ad778
  #12 [ffff8813dedfbdc0] kswapd at ffffffff811ae92f
  #13 [ffff8813dedfbec0] kthread at ffffffff810a8428
  #14 [ffff8813dedfbf50] ret_from_fork at ffffffff81745242

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Cc: stable@vger.kernel.org
Fixes: bd293d0 ("dm bufio: fix deadlock with loop device")
Depends-on: d0a255e ("loop: set PF_MEMALLOC_NOIO for the worker thread")
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
randomhydrosol pushed a commit to randomhydrosol/linux-hardened that referenced this issue Sep 10, 2019
Revert the commit bd293d0. The proper
fix has been made available with commit d0a255e ("loop: set
PF_MEMALLOC_NOIO for the worker thread").

Note that the fix offered by commit bd293d0 doesn't really prevent
the deadlock from occuring - if we look at the stacktrace reported by
Junxiao Bi, we see that it hangs in bit_wait_io and not on the mutex -
i.e. it has already successfully taken the mutex. Changing the mutex
from mutex_lock to mutex_trylock won't help with deadlocks that happen
afterwards.

PID: 474    TASK: ffff8813e11f4600  CPU: 10  COMMAND: "kswapd0"
   #0 [ffff8813dedfb938] __schedule at ffffffff8173f405
   GrapheneOS#1 [ffff8813dedfb990] schedule at ffffffff8173fa27
   GrapheneOS#2 [ffff8813dedfb9b0] schedule_timeout at ffffffff81742fec
   GrapheneOS#3 [ffff8813dedfba60] io_schedule_timeout at ffffffff8173f186
   GrapheneOS#4 [ffff8813dedfbaa0] bit_wait_io at ffffffff8174034f
   GrapheneOS#5 [ffff8813dedfbac0] __wait_on_bit at ffffffff8173fec8
   GrapheneOS#6 [ffff8813dedfbb10] out_of_line_wait_on_bit at ffffffff8173ff81
   GrapheneOS#7 [ffff8813dedfbb90] __make_buffer_clean at ffffffffa038736f [dm_bufio]
   GrapheneOS#8 [ffff8813dedfbbb0] __try_evict_buffer at ffffffffa0387bb8 [dm_bufio]
   GrapheneOS#9 [ffff8813dedfbbd0] dm_bufio_shrink_scan at ffffffffa0387cc3 [dm_bufio]
  GrapheneOS#10 [ffff8813dedfbc40] shrink_slab at ffffffff811a87ce
  GrapheneOS#11 [ffff8813dedfbd30] shrink_zone at ffffffff811ad778
  GrapheneOS#12 [ffff8813dedfbdc0] kswapd at ffffffff811ae92f
  GrapheneOS#13 [ffff8813dedfbec0] kthread at ffffffff810a8428
  GrapheneOS#14 [ffff8813dedfbf50] ret_from_fork at ffffffff81745242

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Cc: stable@vger.kernel.org
Fixes: bd293d0 ("dm bufio: fix deadlock with loop device")
Depends-on: d0a255e ("loop: set PF_MEMALLOC_NOIO for the worker thread")
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
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