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Question is it advisable to set sysctl value kernel.unprivileged_userns_clone = 1 for Desktop PC usage for using flatpaks & chromium . #66

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Anish-M-code opened this issue Mar 21, 2022 · 2 comments

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@Anish-M-code
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Hi @anthraxx , total newbie here , Actually in https://wiki.archlinux.org/title/security section Sandboxing Applications , it is mentioned that kernel.unprivileged_userns_clone = 0 is set by default for linux hardened but flatpak , chromium requires kernel.unprivileged_userns_clone = 1 to work properly. so is it advisable to enable it? I want to take advantage of hardened kernel but except this sysctl hardening work.

I have read workarounds ,like using bubblewrap-suid for flatpak and chromium using suid for layer-1 isolation but i have learnt that suid programs are dangerous , i dont know if setting kernel.unprivileged_userns_clone = 1 is more dangerous than using suid , any guidance will be greatly appreciated.

@Anish-M-code Anish-M-code changed the title Question is it advisable to set sysctl value kernel.unprivileged_userns_clone = 1 for Desktop PC usage . Question is it advisable to set sysctl value kernel.unprivileged_userns_clone = 1 for Desktop PC usage for uage of flatpaks & chromium . Mar 21, 2022
@Anish-M-code Anish-M-code changed the title Question is it advisable to set sysctl value kernel.unprivileged_userns_clone = 1 for Desktop PC usage for uage of flatpaks & chromium . Question is it advisable to set sysctl value kernel.unprivileged_userns_clone = 1 for Desktop PC usage for using flatpaks & chromium . Mar 21, 2022
@Bernhard40
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Sometimes there is no alternative, i.e. chromium flatpak won't work with bubblewrap-suid. If you run most desktop apps in containers/sandboxes then there may be more security benefits of setting kernel.unprivileged_userns_clone = 1 than the opposite.

@Anish-M-code
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Thanks for replying @Bernhard40 , i enabled kernel.unprivileged_userns_clone = 1 in sysctl.conf and using linux hardened but chromium shows ptrace with yama LSM non broker as not present. But when kernel.unprivileged_userns_clone = 0 it shows yama LSM non broker as yes in sandbox status, is this behaviour expected while using linux hardened kernel ?

As far in sysct.conf i have only set kernel.yama.ptrace_scope = 3 and kernel.unprivileged_userns_clone = 1

chromium_suid

usernamespace

anthraxx pushed a commit that referenced this issue Mar 25, 2022
[ Upstream commit f1cb347 ]

rsi_get_* functions rely on an offset variable from usb
input. The size of usb input is RSI_MAX_RX_USB_PKT_SIZE(3000),
while 2-byte offset can be up to 0xFFFF. Thus a large offset
can cause out-of-bounds read.

The patch adds a bound checking condition when rcv_pkt_len is 0,
indicating it's USB. It's unclear whether this is triggerable
from other type of bus. The following check might help in that case.
offset > rcv_pkt_len - FRAME_DESC_SZ

The bug is trigerrable with conpromised/malfunctioning USB devices.
I tested the patch with the crashing input and got no more bug report.

Attached is the KASAN report from fuzzing.

BUG: KASAN: slab-out-of-bounds in rsi_read_pkt+0x42e/0x500 [rsi_91x]
Read of size 2 at addr ffff888019439fdb by task RX-Thread/227

CPU: 0 PID: 227 Comm: RX-Thread Not tainted 5.6.0 #66
Call Trace:
 dump_stack+0x76/0xa0
 print_address_description.constprop.0+0x16/0x200
 ? rsi_read_pkt+0x42e/0x500 [rsi_91x]
 ? rsi_read_pkt+0x42e/0x500 [rsi_91x]
 __kasan_report.cold+0x37/0x7c
 ? rsi_read_pkt+0x42e/0x500 [rsi_91x]
 kasan_report+0xe/0x20
 rsi_read_pkt+0x42e/0x500 [rsi_91x]
 rsi_usb_rx_thread+0x1b1/0x2fc [rsi_usb]
 ? rsi_probe+0x16a0/0x16a0 [rsi_usb]
 ? _raw_spin_lock_irqsave+0x7b/0xd0
 ? _raw_spin_trylock_bh+0x120/0x120
 ? __wake_up_common+0x10b/0x520
 ? rsi_probe+0x16a0/0x16a0 [rsi_usb]
 kthread+0x2b5/0x3b0
 ? kthread_create_on_node+0xd0/0xd0
 ret_from_fork+0x22/0x40

Reported-by: Brendan Dolan-Gavitt <brendandg@nyu.edu>
Signed-off-by: Zekun Shen <bruceshenzk@gmail.com>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
Link: https://lore.kernel.org/r/YXxXS4wgu2OsmlVv@10-18-43-117.dynapool.wireless.nyu.edu
Signed-off-by: Sasha Levin <sashal@kernel.org>
anthraxx pushed a commit that referenced this issue Jul 19, 2023
[ Upstream commit 85fadc0 ]

The initial memblock metadata is accessed from kernel image mapping. The
regions arrays need to "reallocated" from memblock and accessed through
linear mapping to cover more memblock regions. So the resizing should
not be allowed until linear mapping is ready. Note that there are
memblock allocations when building linear mapping.

This patch is similar to 24cc61d ("arm64: memblock: don't permit
memblock resizing until linear mapping is up").

In following log, many memblock regions are reserved before
create_linear_mapping_page_table(). And then it triggered reallocation
of memblock.reserved.regions and memcpy the old array in kernel image
mapping to the new array in linear mapping which caused a page fault.

[    0.000000] memblock_reserve: [0x00000000bf01f000-0x00000000bf01ffff] early_init_fdt_scan_reserved_mem+0x28c/0x2c6
[    0.000000] memblock_reserve: [0x00000000bf021000-0x00000000bf021fff] early_init_fdt_scan_reserved_mem+0x28c/0x2c6
[    0.000000] memblock_reserve: [0x00000000bf023000-0x00000000bf023fff] early_init_fdt_scan_reserved_mem+0x28c/0x2c6
[    0.000000] memblock_reserve: [0x00000000bf025000-0x00000000bf025fff] early_init_fdt_scan_reserved_mem+0x28c/0x2c6
[    0.000000] memblock_reserve: [0x00000000bf027000-0x00000000bf027fff] early_init_fdt_scan_reserved_mem+0x28c/0x2c6
[    0.000000] memblock_reserve: [0x00000000bf029000-0x00000000bf029fff] early_init_fdt_scan_reserved_mem+0x28c/0x2c6
[    0.000000] memblock_reserve: [0x00000000bf02b000-0x00000000bf02bfff] early_init_fdt_scan_reserved_mem+0x28c/0x2c6
[    0.000000] memblock_reserve: [0x00000000bf02d000-0x00000000bf02dfff] early_init_fdt_scan_reserved_mem+0x28c/0x2c6
[    0.000000] memblock_reserve: [0x00000000bf02f000-0x00000000bf02ffff] early_init_fdt_scan_reserved_mem+0x28c/0x2c6
[    0.000000] memblock_reserve: [0x00000000bf030000-0x00000000bf030fff] early_init_fdt_scan_reserved_mem+0x28c/0x2c6
[    0.000000] OF: reserved mem: 0x0000000080000000..0x000000008007ffff (512 KiB) map non-reusable mmode_resv0@80000000
[    0.000000] memblock_reserve: [0x00000000bf000000-0x00000000bf001fed] paging_init+0x19a/0x5ae
[    0.000000] memblock_phys_alloc_range: 4096 bytes align=0x1000 from=0x0000000000000000 max_addr=0x0000000000000000 alloc_pmd_fixmap+0x14/0x1c
[    0.000000] memblock_reserve: [0x000000017ffff000-0x000000017fffffff] memblock_alloc_range_nid+0xb8/0x128
[    0.000000] memblock: reserved is doubled to 256 at [0x000000017fffd000-0x000000017fffe7ff]
[    0.000000] Unable to handle kernel paging request at virtual address ff600000ffffd000
[    0.000000] Oops [#1]
[    0.000000] Modules linked in:
[    0.000000] CPU: 0 PID: 0 Comm: swapper Not tainted 6.4.0-rc1-00011-g99a670b2069c #66
[    0.000000] Hardware name: riscv-virtio,qemu (DT)
[    0.000000] epc : __memcpy+0x60/0xf8
[    0.000000]  ra : memblock_double_array+0x192/0x248
[    0.000000] epc : ffffffff8081d214 ra : ffffffff80a3dfc0 sp : ffffffff81403bd0
[    0.000000]  gp : ffffffff814fbb38 tp : ffffffff8140dac0 t0 : 0000000001600000
[    0.000000]  t1 : 0000000000000000 t2 : 000000008f001000 s0 : ffffffff81403c60
[    0.000000]  s1 : ffffffff80c0bc98 a0 : ff600000ffffd000 a1 : ffffffff80c0bcd8
[    0.000000]  a2 : 0000000000000c00 a3 : ffffffff80c0c8d8 a4 : 0000000080000000
[    0.000000]  a5 : 0000000000080000 a6 : 0000000000000000 a7 : 0000000080200000
[    0.000000]  s2 : ff600000ffffd000 s3 : 0000000000002000 s4 : 0000000000000c00
[    0.000000]  s5 : ffffffff80c0bc60 s6 : ffffffff80c0bcc8 s7 : 0000000000000000
[    0.000000]  s8 : ffffffff814fd0a8 s9 : 000000017fffe7ff s10: 0000000000000000
[    0.000000]  s11: 0000000000001000 t3 : 0000000000001000 t4 : 0000000000000000
[    0.000000]  t5 : 000000008f003000 t6 : ff600000ffffd000
[    0.000000] status: 0000000200000100 badaddr: ff600000ffffd000 cause: 000000000000000f
[    0.000000] [<ffffffff8081d214>] __memcpy+0x60/0xf8
[    0.000000] [<ffffffff80a3e1a2>] memblock_add_range.isra.14+0x12c/0x162
[    0.000000] [<ffffffff80a3e36a>] memblock_reserve+0x6e/0x8c
[    0.000000] [<ffffffff80a123fc>] memblock_alloc_range_nid+0xb8/0x128
[    0.000000] [<ffffffff80a1256a>] memblock_phys_alloc_range+0x5e/0x6a
[    0.000000] [<ffffffff80a04732>] alloc_pmd_fixmap+0x14/0x1c
[    0.000000] [<ffffffff80a0475a>] alloc_p4d_fixmap+0xc/0x14
[    0.000000] [<ffffffff80a04a36>] create_pgd_mapping+0x98/0x17c
[    0.000000] [<ffffffff80a04e9e>] create_linear_mapping_range.constprop.10+0xe4/0x112
[    0.000000] [<ffffffff80a05bb8>] paging_init+0x3ec/0x5ae
[    0.000000] [<ffffffff80a03354>] setup_arch+0xb2/0x576
[    0.000000] [<ffffffff80a00726>] start_kernel+0x72/0x57e
[    0.000000] Code: b303 0285 b383 0305 be03 0385 be83 0405 bf03 0485 (b023) 00ef
[    0.000000] ---[ end trace 0000000000000000 ]---
[    0.000000] Kernel panic - not syncing: Attempted to kill the idle task!
[    0.000000] ---[ end Kernel panic - not syncing: Attempted to kill the idle task! ]---

Fixes: 671f9a3 ("RISC-V: Setup initial page tables in two stages")
Signed-off-by: Woody Zhang <woodylab@foxmail.com>
Tested-by: Song Shuai <songshuaishuai@tinylab.org>
Link: https://lore.kernel.org/r/tencent_FBB94CE615C5CCE7701CD39C15CCE0EE9706@qq.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
anthraxx pushed a commit that referenced this issue Jul 19, 2023
[ Upstream commit 85fadc0 ]

The initial memblock metadata is accessed from kernel image mapping. The
regions arrays need to "reallocated" from memblock and accessed through
linear mapping to cover more memblock regions. So the resizing should
not be allowed until linear mapping is ready. Note that there are
memblock allocations when building linear mapping.

This patch is similar to 24cc61d ("arm64: memblock: don't permit
memblock resizing until linear mapping is up").

In following log, many memblock regions are reserved before
create_linear_mapping_page_table(). And then it triggered reallocation
of memblock.reserved.regions and memcpy the old array in kernel image
mapping to the new array in linear mapping which caused a page fault.

[    0.000000] memblock_reserve: [0x00000000bf01f000-0x00000000bf01ffff] early_init_fdt_scan_reserved_mem+0x28c/0x2c6
[    0.000000] memblock_reserve: [0x00000000bf021000-0x00000000bf021fff] early_init_fdt_scan_reserved_mem+0x28c/0x2c6
[    0.000000] memblock_reserve: [0x00000000bf023000-0x00000000bf023fff] early_init_fdt_scan_reserved_mem+0x28c/0x2c6
[    0.000000] memblock_reserve: [0x00000000bf025000-0x00000000bf025fff] early_init_fdt_scan_reserved_mem+0x28c/0x2c6
[    0.000000] memblock_reserve: [0x00000000bf027000-0x00000000bf027fff] early_init_fdt_scan_reserved_mem+0x28c/0x2c6
[    0.000000] memblock_reserve: [0x00000000bf029000-0x00000000bf029fff] early_init_fdt_scan_reserved_mem+0x28c/0x2c6
[    0.000000] memblock_reserve: [0x00000000bf02b000-0x00000000bf02bfff] early_init_fdt_scan_reserved_mem+0x28c/0x2c6
[    0.000000] memblock_reserve: [0x00000000bf02d000-0x00000000bf02dfff] early_init_fdt_scan_reserved_mem+0x28c/0x2c6
[    0.000000] memblock_reserve: [0x00000000bf02f000-0x00000000bf02ffff] early_init_fdt_scan_reserved_mem+0x28c/0x2c6
[    0.000000] memblock_reserve: [0x00000000bf030000-0x00000000bf030fff] early_init_fdt_scan_reserved_mem+0x28c/0x2c6
[    0.000000] OF: reserved mem: 0x0000000080000000..0x000000008007ffff (512 KiB) map non-reusable mmode_resv0@80000000
[    0.000000] memblock_reserve: [0x00000000bf000000-0x00000000bf001fed] paging_init+0x19a/0x5ae
[    0.000000] memblock_phys_alloc_range: 4096 bytes align=0x1000 from=0x0000000000000000 max_addr=0x0000000000000000 alloc_pmd_fixmap+0x14/0x1c
[    0.000000] memblock_reserve: [0x000000017ffff000-0x000000017fffffff] memblock_alloc_range_nid+0xb8/0x128
[    0.000000] memblock: reserved is doubled to 256 at [0x000000017fffd000-0x000000017fffe7ff]
[    0.000000] Unable to handle kernel paging request at virtual address ff600000ffffd000
[    0.000000] Oops [#1]
[    0.000000] Modules linked in:
[    0.000000] CPU: 0 PID: 0 Comm: swapper Not tainted 6.4.0-rc1-00011-g99a670b2069c #66
[    0.000000] Hardware name: riscv-virtio,qemu (DT)
[    0.000000] epc : __memcpy+0x60/0xf8
[    0.000000]  ra : memblock_double_array+0x192/0x248
[    0.000000] epc : ffffffff8081d214 ra : ffffffff80a3dfc0 sp : ffffffff81403bd0
[    0.000000]  gp : ffffffff814fbb38 tp : ffffffff8140dac0 t0 : 0000000001600000
[    0.000000]  t1 : 0000000000000000 t2 : 000000008f001000 s0 : ffffffff81403c60
[    0.000000]  s1 : ffffffff80c0bc98 a0 : ff600000ffffd000 a1 : ffffffff80c0bcd8
[    0.000000]  a2 : 0000000000000c00 a3 : ffffffff80c0c8d8 a4 : 0000000080000000
[    0.000000]  a5 : 0000000000080000 a6 : 0000000000000000 a7 : 0000000080200000
[    0.000000]  s2 : ff600000ffffd000 s3 : 0000000000002000 s4 : 0000000000000c00
[    0.000000]  s5 : ffffffff80c0bc60 s6 : ffffffff80c0bcc8 s7 : 0000000000000000
[    0.000000]  s8 : ffffffff814fd0a8 s9 : 000000017fffe7ff s10: 0000000000000000
[    0.000000]  s11: 0000000000001000 t3 : 0000000000001000 t4 : 0000000000000000
[    0.000000]  t5 : 000000008f003000 t6 : ff600000ffffd000
[    0.000000] status: 0000000200000100 badaddr: ff600000ffffd000 cause: 000000000000000f
[    0.000000] [<ffffffff8081d214>] __memcpy+0x60/0xf8
[    0.000000] [<ffffffff80a3e1a2>] memblock_add_range.isra.14+0x12c/0x162
[    0.000000] [<ffffffff80a3e36a>] memblock_reserve+0x6e/0x8c
[    0.000000] [<ffffffff80a123fc>] memblock_alloc_range_nid+0xb8/0x128
[    0.000000] [<ffffffff80a1256a>] memblock_phys_alloc_range+0x5e/0x6a
[    0.000000] [<ffffffff80a04732>] alloc_pmd_fixmap+0x14/0x1c
[    0.000000] [<ffffffff80a0475a>] alloc_p4d_fixmap+0xc/0x14
[    0.000000] [<ffffffff80a04a36>] create_pgd_mapping+0x98/0x17c
[    0.000000] [<ffffffff80a04e9e>] create_linear_mapping_range.constprop.10+0xe4/0x112
[    0.000000] [<ffffffff80a05bb8>] paging_init+0x3ec/0x5ae
[    0.000000] [<ffffffff80a03354>] setup_arch+0xb2/0x576
[    0.000000] [<ffffffff80a00726>] start_kernel+0x72/0x57e
[    0.000000] Code: b303 0285 b383 0305 be03 0385 be83 0405 bf03 0485 (b023) 00ef
[    0.000000] ---[ end trace 0000000000000000 ]---
[    0.000000] Kernel panic - not syncing: Attempted to kill the idle task!
[    0.000000] ---[ end Kernel panic - not syncing: Attempted to kill the idle task! ]---

Fixes: 671f9a3 ("RISC-V: Setup initial page tables in two stages")
Signed-off-by: Woody Zhang <woodylab@foxmail.com>
Tested-by: Song Shuai <songshuaishuai@tinylab.org>
Link: https://lore.kernel.org/r/tencent_FBB94CE615C5CCE7701CD39C15CCE0EE9706@qq.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
anthraxx pushed a commit that referenced this issue Jul 24, 2023
[ Upstream commit 85fadc0 ]

The initial memblock metadata is accessed from kernel image mapping. The
regions arrays need to "reallocated" from memblock and accessed through
linear mapping to cover more memblock regions. So the resizing should
not be allowed until linear mapping is ready. Note that there are
memblock allocations when building linear mapping.

This patch is similar to 24cc61d ("arm64: memblock: don't permit
memblock resizing until linear mapping is up").

In following log, many memblock regions are reserved before
create_linear_mapping_page_table(). And then it triggered reallocation
of memblock.reserved.regions and memcpy the old array in kernel image
mapping to the new array in linear mapping which caused a page fault.

[    0.000000] memblock_reserve: [0x00000000bf01f000-0x00000000bf01ffff] early_init_fdt_scan_reserved_mem+0x28c/0x2c6
[    0.000000] memblock_reserve: [0x00000000bf021000-0x00000000bf021fff] early_init_fdt_scan_reserved_mem+0x28c/0x2c6
[    0.000000] memblock_reserve: [0x00000000bf023000-0x00000000bf023fff] early_init_fdt_scan_reserved_mem+0x28c/0x2c6
[    0.000000] memblock_reserve: [0x00000000bf025000-0x00000000bf025fff] early_init_fdt_scan_reserved_mem+0x28c/0x2c6
[    0.000000] memblock_reserve: [0x00000000bf027000-0x00000000bf027fff] early_init_fdt_scan_reserved_mem+0x28c/0x2c6
[    0.000000] memblock_reserve: [0x00000000bf029000-0x00000000bf029fff] early_init_fdt_scan_reserved_mem+0x28c/0x2c6
[    0.000000] memblock_reserve: [0x00000000bf02b000-0x00000000bf02bfff] early_init_fdt_scan_reserved_mem+0x28c/0x2c6
[    0.000000] memblock_reserve: [0x00000000bf02d000-0x00000000bf02dfff] early_init_fdt_scan_reserved_mem+0x28c/0x2c6
[    0.000000] memblock_reserve: [0x00000000bf02f000-0x00000000bf02ffff] early_init_fdt_scan_reserved_mem+0x28c/0x2c6
[    0.000000] memblock_reserve: [0x00000000bf030000-0x00000000bf030fff] early_init_fdt_scan_reserved_mem+0x28c/0x2c6
[    0.000000] OF: reserved mem: 0x0000000080000000..0x000000008007ffff (512 KiB) map non-reusable mmode_resv0@80000000
[    0.000000] memblock_reserve: [0x00000000bf000000-0x00000000bf001fed] paging_init+0x19a/0x5ae
[    0.000000] memblock_phys_alloc_range: 4096 bytes align=0x1000 from=0x0000000000000000 max_addr=0x0000000000000000 alloc_pmd_fixmap+0x14/0x1c
[    0.000000] memblock_reserve: [0x000000017ffff000-0x000000017fffffff] memblock_alloc_range_nid+0xb8/0x128
[    0.000000] memblock: reserved is doubled to 256 at [0x000000017fffd000-0x000000017fffe7ff]
[    0.000000] Unable to handle kernel paging request at virtual address ff600000ffffd000
[    0.000000] Oops [#1]
[    0.000000] Modules linked in:
[    0.000000] CPU: 0 PID: 0 Comm: swapper Not tainted 6.4.0-rc1-00011-g99a670b2069c #66
[    0.000000] Hardware name: riscv-virtio,qemu (DT)
[    0.000000] epc : __memcpy+0x60/0xf8
[    0.000000]  ra : memblock_double_array+0x192/0x248
[    0.000000] epc : ffffffff8081d214 ra : ffffffff80a3dfc0 sp : ffffffff81403bd0
[    0.000000]  gp : ffffffff814fbb38 tp : ffffffff8140dac0 t0 : 0000000001600000
[    0.000000]  t1 : 0000000000000000 t2 : 000000008f001000 s0 : ffffffff81403c60
[    0.000000]  s1 : ffffffff80c0bc98 a0 : ff600000ffffd000 a1 : ffffffff80c0bcd8
[    0.000000]  a2 : 0000000000000c00 a3 : ffffffff80c0c8d8 a4 : 0000000080000000
[    0.000000]  a5 : 0000000000080000 a6 : 0000000000000000 a7 : 0000000080200000
[    0.000000]  s2 : ff600000ffffd000 s3 : 0000000000002000 s4 : 0000000000000c00
[    0.000000]  s5 : ffffffff80c0bc60 s6 : ffffffff80c0bcc8 s7 : 0000000000000000
[    0.000000]  s8 : ffffffff814fd0a8 s9 : 000000017fffe7ff s10: 0000000000000000
[    0.000000]  s11: 0000000000001000 t3 : 0000000000001000 t4 : 0000000000000000
[    0.000000]  t5 : 000000008f003000 t6 : ff600000ffffd000
[    0.000000] status: 0000000200000100 badaddr: ff600000ffffd000 cause: 000000000000000f
[    0.000000] [<ffffffff8081d214>] __memcpy+0x60/0xf8
[    0.000000] [<ffffffff80a3e1a2>] memblock_add_range.isra.14+0x12c/0x162
[    0.000000] [<ffffffff80a3e36a>] memblock_reserve+0x6e/0x8c
[    0.000000] [<ffffffff80a123fc>] memblock_alloc_range_nid+0xb8/0x128
[    0.000000] [<ffffffff80a1256a>] memblock_phys_alloc_range+0x5e/0x6a
[    0.000000] [<ffffffff80a04732>] alloc_pmd_fixmap+0x14/0x1c
[    0.000000] [<ffffffff80a0475a>] alloc_p4d_fixmap+0xc/0x14
[    0.000000] [<ffffffff80a04a36>] create_pgd_mapping+0x98/0x17c
[    0.000000] [<ffffffff80a04e9e>] create_linear_mapping_range.constprop.10+0xe4/0x112
[    0.000000] [<ffffffff80a05bb8>] paging_init+0x3ec/0x5ae
[    0.000000] [<ffffffff80a03354>] setup_arch+0xb2/0x576
[    0.000000] [<ffffffff80a00726>] start_kernel+0x72/0x57e
[    0.000000] Code: b303 0285 b383 0305 be03 0385 be83 0405 bf03 0485 (b023) 00ef
[    0.000000] ---[ end trace 0000000000000000 ]---
[    0.000000] Kernel panic - not syncing: Attempted to kill the idle task!
[    0.000000] ---[ end Kernel panic - not syncing: Attempted to kill the idle task! ]---

Fixes: 671f9a3 ("RISC-V: Setup initial page tables in two stages")
Signed-off-by: Woody Zhang <woodylab@foxmail.com>
Tested-by: Song Shuai <songshuaishuai@tinylab.org>
Link: https://lore.kernel.org/r/tencent_FBB94CE615C5CCE7701CD39C15CCE0EE9706@qq.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
anthraxx pushed a commit that referenced this issue Feb 24, 2024
[ Upstream commit ed8b94f ]

When a PCI device is dynamically added, the kernel oopses with a NULL
pointer dereference:

  BUG: Kernel NULL pointer dereference on read at 0x00000030
  Faulting instruction address: 0xc0000000006bbe5c
  Oops: Kernel access of bad area, sig: 11 [#1]
  LE PAGE_SIZE=64K MMU=Radix SMP NR_CPUS=2048 NUMA pSeries
  Modules linked in: rpadlpar_io rpaphp rpcsec_gss_krb5 auth_rpcgss nfsv4 dns_resolver nfs lockd grace fscache netfs xsk_diag bonding nft_compat nf_tables nfnetlink rfkill binfmt_misc dm_multipath rpcrdma sunrpc rdma_ucm ib_srpt ib_isert iscsi_target_mod target_core_mod ib_umad ib_iser libiscsi scsi_transport_iscsi ib_ipoib rdma_cm iw_cm ib_cm mlx5_ib ib_uverbs ib_core pseries_rng drm drm_panel_orientation_quirks xfs libcrc32c mlx5_core mlxfw sd_mod t10_pi sg tls ibmvscsi ibmveth scsi_transport_srp vmx_crypto pseries_wdt psample dm_mirror dm_region_hash dm_log dm_mod fuse
  CPU: 17 PID: 2685 Comm: drmgr Not tainted 6.7.0-203405+ #66
  Hardware name: IBM,9080-HEX POWER10 (raw) 0x800200 0xf000006 of:IBM,FW1060.00 (NH1060_008) hv:phyp pSeries
  NIP:  c0000000006bbe5c LR: c000000000a13e68 CTR: c0000000000579f8
  REGS: c00000009924f240 TRAP: 0300   Not tainted  (6.7.0-203405+)
  MSR:  8000000000009033 <SF,EE,ME,IR,DR,RI,LE>  CR: 24002220  XER: 20040006
  CFAR: c000000000a13e64 DAR: 0000000000000030 DSISR: 40000000 IRQMASK: 0
  ...
  NIP sysfs_add_link_to_group+0x34/0x94
  LR  iommu_device_link+0x5c/0x118
  Call Trace:
   iommu_init_device+0x26c/0x318 (unreliable)
   iommu_device_link+0x5c/0x118
   iommu_init_device+0xa8/0x318
   iommu_probe_device+0xc0/0x134
   iommu_bus_notifier+0x44/0x104
   notifier_call_chain+0xb8/0x19c
   blocking_notifier_call_chain+0x64/0x98
   bus_notify+0x50/0x7c
   device_add+0x640/0x918
   pci_device_add+0x23c/0x298
   of_create_pci_dev+0x400/0x884
   of_scan_pci_dev+0x124/0x1b0
   __of_scan_bus+0x78/0x18c
   pcibios_scan_phb+0x2a4/0x3b0
   init_phb_dynamic+0xb8/0x110
   dlpar_add_slot+0x170/0x3b8 [rpadlpar_io]
   add_slot_store.part.0+0xb4/0x130 [rpadlpar_io]
   kobj_attr_store+0x2c/0x48
   sysfs_kf_write+0x64/0x78
   kernfs_fop_write_iter+0x1b0/0x290
   vfs_write+0x350/0x4a0
   ksys_write+0x84/0x140
   system_call_exception+0x124/0x330
   system_call_vectored_common+0x15c/0x2ec

Commit a940904 ("powerpc/iommu: Add iommu_ops to report capabilities
and allow blocking domains") broke DLPAR add of PCI devices.

The above added iommu_device structure to pci_controller. During
system boot, PCI devices are discovered and this newly added iommu_device
structure is initialized by a call to iommu_device_register().

During DLPAR add of a PCI device, a new pci_controller structure is
allocated but there are no calls made to iommu_device_register()
interface.

Fix is to register the iommu device during DLPAR add as well.

Fixes: a940904 ("powerpc/iommu: Add iommu_ops to report capabilities and allow blocking domains")
Signed-off-by: Gaurav Batra <gbatra@linux.ibm.com>
[mpe: Trim oops and tweak some change log wording]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20240122222407.39603-1-gbatra@linux.ibm.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
anthraxx pushed a commit that referenced this issue Feb 24, 2024
[ Upstream commit ed8b94f ]

When a PCI device is dynamically added, the kernel oopses with a NULL
pointer dereference:

  BUG: Kernel NULL pointer dereference on read at 0x00000030
  Faulting instruction address: 0xc0000000006bbe5c
  Oops: Kernel access of bad area, sig: 11 [#1]
  LE PAGE_SIZE=64K MMU=Radix SMP NR_CPUS=2048 NUMA pSeries
  Modules linked in: rpadlpar_io rpaphp rpcsec_gss_krb5 auth_rpcgss nfsv4 dns_resolver nfs lockd grace fscache netfs xsk_diag bonding nft_compat nf_tables nfnetlink rfkill binfmt_misc dm_multipath rpcrdma sunrpc rdma_ucm ib_srpt ib_isert iscsi_target_mod target_core_mod ib_umad ib_iser libiscsi scsi_transport_iscsi ib_ipoib rdma_cm iw_cm ib_cm mlx5_ib ib_uverbs ib_core pseries_rng drm drm_panel_orientation_quirks xfs libcrc32c mlx5_core mlxfw sd_mod t10_pi sg tls ibmvscsi ibmveth scsi_transport_srp vmx_crypto pseries_wdt psample dm_mirror dm_region_hash dm_log dm_mod fuse
  CPU: 17 PID: 2685 Comm: drmgr Not tainted 6.7.0-203405+ #66
  Hardware name: IBM,9080-HEX POWER10 (raw) 0x800200 0xf000006 of:IBM,FW1060.00 (NH1060_008) hv:phyp pSeries
  NIP:  c0000000006bbe5c LR: c000000000a13e68 CTR: c0000000000579f8
  REGS: c00000009924f240 TRAP: 0300   Not tainted  (6.7.0-203405+)
  MSR:  8000000000009033 <SF,EE,ME,IR,DR,RI,LE>  CR: 24002220  XER: 20040006
  CFAR: c000000000a13e64 DAR: 0000000000000030 DSISR: 40000000 IRQMASK: 0
  ...
  NIP sysfs_add_link_to_group+0x34/0x94
  LR  iommu_device_link+0x5c/0x118
  Call Trace:
   iommu_init_device+0x26c/0x318 (unreliable)
   iommu_device_link+0x5c/0x118
   iommu_init_device+0xa8/0x318
   iommu_probe_device+0xc0/0x134
   iommu_bus_notifier+0x44/0x104
   notifier_call_chain+0xb8/0x19c
   blocking_notifier_call_chain+0x64/0x98
   bus_notify+0x50/0x7c
   device_add+0x640/0x918
   pci_device_add+0x23c/0x298
   of_create_pci_dev+0x400/0x884
   of_scan_pci_dev+0x124/0x1b0
   __of_scan_bus+0x78/0x18c
   pcibios_scan_phb+0x2a4/0x3b0
   init_phb_dynamic+0xb8/0x110
   dlpar_add_slot+0x170/0x3b8 [rpadlpar_io]
   add_slot_store.part.0+0xb4/0x130 [rpadlpar_io]
   kobj_attr_store+0x2c/0x48
   sysfs_kf_write+0x64/0x78
   kernfs_fop_write_iter+0x1b0/0x290
   vfs_write+0x350/0x4a0
   ksys_write+0x84/0x140
   system_call_exception+0x124/0x330
   system_call_vectored_common+0x15c/0x2ec

Commit a940904 ("powerpc/iommu: Add iommu_ops to report capabilities
and allow blocking domains") broke DLPAR add of PCI devices.

The above added iommu_device structure to pci_controller. During
system boot, PCI devices are discovered and this newly added iommu_device
structure is initialized by a call to iommu_device_register().

During DLPAR add of a PCI device, a new pci_controller structure is
allocated but there are no calls made to iommu_device_register()
interface.

Fix is to register the iommu device during DLPAR add as well.

Fixes: a940904 ("powerpc/iommu: Add iommu_ops to report capabilities and allow blocking domains")
Signed-off-by: Gaurav Batra <gbatra@linux.ibm.com>
[mpe: Trim oops and tweak some change log wording]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20240122222407.39603-1-gbatra@linux.ibm.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
anthraxx pushed a commit that referenced this issue Mar 3, 2024
…ntroller

[ Upstream commit a5c57fd ]

When a PCI device is dynamically added, the kernel oopses with a NULL
pointer dereference:

  BUG: Kernel NULL pointer dereference on read at 0x00000030
  Faulting instruction address: 0xc0000000006bbe5c
  Oops: Kernel access of bad area, sig: 11 [#1]
  LE PAGE_SIZE=64K MMU=Radix SMP NR_CPUS=2048 NUMA pSeries
  Modules linked in: rpadlpar_io rpaphp rpcsec_gss_krb5 auth_rpcgss nfsv4 dns_resolver nfs lockd grace fscache netfs xsk_diag bonding nft_compat nf_tables nfnetlink rfkill binfmt_misc dm_multipath rpcrdma sunrpc rdma_ucm ib_srpt ib_isert iscsi_target_mod target_core_mod ib_umad ib_iser libiscsi scsi_transport_iscsi ib_ipoib rdma_cm iw_cm ib_cm mlx5_ib ib_uverbs ib_core pseries_rng drm drm_panel_orientation_quirks xfs libcrc32c mlx5_core mlxfw sd_mod t10_pi sg tls ibmvscsi ibmveth scsi_transport_srp vmx_crypto pseries_wdt psample dm_mirror dm_region_hash dm_log dm_mod fuse
  CPU: 17 PID: 2685 Comm: drmgr Not tainted 6.7.0-203405+ #66
  Hardware name: IBM,9080-HEX POWER10 (raw) 0x800200 0xf000006 of:IBM,FW1060.00 (NH1060_008) hv:phyp pSeries
  NIP:  c0000000006bbe5c LR: c000000000a13e68 CTR: c0000000000579f8
  REGS: c00000009924f240 TRAP: 0300   Not tainted  (6.7.0-203405+)
  MSR:  8000000000009033 <SF,EE,ME,IR,DR,RI,LE>  CR: 24002220  XER: 20040006
  CFAR: c000000000a13e64 DAR: 0000000000000030 DSISR: 40000000 IRQMASK: 0
  ...
  NIP sysfs_add_link_to_group+0x34/0x94
  LR  iommu_device_link+0x5c/0x118
  Call Trace:
   iommu_init_device+0x26c/0x318 (unreliable)
   iommu_device_link+0x5c/0x118
   iommu_init_device+0xa8/0x318
   iommu_probe_device+0xc0/0x134
   iommu_bus_notifier+0x44/0x104
   notifier_call_chain+0xb8/0x19c
   blocking_notifier_call_chain+0x64/0x98
   bus_notify+0x50/0x7c
   device_add+0x640/0x918
   pci_device_add+0x23c/0x298
   of_create_pci_dev+0x400/0x884
   of_scan_pci_dev+0x124/0x1b0
   __of_scan_bus+0x78/0x18c
   pcibios_scan_phb+0x2a4/0x3b0
   init_phb_dynamic+0xb8/0x110
   dlpar_add_slot+0x170/0x3b8 [rpadlpar_io]
   add_slot_store.part.0+0xb4/0x130 [rpadlpar_io]
   kobj_attr_store+0x2c/0x48
   sysfs_kf_write+0x64/0x78
   kernfs_fop_write_iter+0x1b0/0x290
   vfs_write+0x350/0x4a0
   ksys_write+0x84/0x140
   system_call_exception+0x124/0x330
   system_call_vectored_common+0x15c/0x2ec

Commit a940904 ("powerpc/iommu: Add iommu_ops to report capabilities
and allow blocking domains") broke DLPAR add of PCI devices.

The above added iommu_device structure to pci_controller. During
system boot, PCI devices are discovered and this newly added iommu_device
structure is initialized by a call to iommu_device_register().

During DLPAR add of a PCI device, a new pci_controller structure is
allocated but there are no calls made to iommu_device_register()
interface.

Fix is to register the iommu device during DLPAR add as well.

Fixes: a940904 ("powerpc/iommu: Add iommu_ops to report capabilities and allow blocking domains")
Signed-off-by: Gaurav Batra <gbatra@linux.ibm.com>
Reviewed-by: Brian King <brking@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20240215221833.4817-1-gbatra@linux.ibm.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
anthraxx pushed a commit that referenced this issue Mar 3, 2024
…ntroller

[ Upstream commit a5c57fd ]

When a PCI device is dynamically added, the kernel oopses with a NULL
pointer dereference:

  BUG: Kernel NULL pointer dereference on read at 0x00000030
  Faulting instruction address: 0xc0000000006bbe5c
  Oops: Kernel access of bad area, sig: 11 [#1]
  LE PAGE_SIZE=64K MMU=Radix SMP NR_CPUS=2048 NUMA pSeries
  Modules linked in: rpadlpar_io rpaphp rpcsec_gss_krb5 auth_rpcgss nfsv4 dns_resolver nfs lockd grace fscache netfs xsk_diag bonding nft_compat nf_tables nfnetlink rfkill binfmt_misc dm_multipath rpcrdma sunrpc rdma_ucm ib_srpt ib_isert iscsi_target_mod target_core_mod ib_umad ib_iser libiscsi scsi_transport_iscsi ib_ipoib rdma_cm iw_cm ib_cm mlx5_ib ib_uverbs ib_core pseries_rng drm drm_panel_orientation_quirks xfs libcrc32c mlx5_core mlxfw sd_mod t10_pi sg tls ibmvscsi ibmveth scsi_transport_srp vmx_crypto pseries_wdt psample dm_mirror dm_region_hash dm_log dm_mod fuse
  CPU: 17 PID: 2685 Comm: drmgr Not tainted 6.7.0-203405+ #66
  Hardware name: IBM,9080-HEX POWER10 (raw) 0x800200 0xf000006 of:IBM,FW1060.00 (NH1060_008) hv:phyp pSeries
  NIP:  c0000000006bbe5c LR: c000000000a13e68 CTR: c0000000000579f8
  REGS: c00000009924f240 TRAP: 0300   Not tainted  (6.7.0-203405+)
  MSR:  8000000000009033 <SF,EE,ME,IR,DR,RI,LE>  CR: 24002220  XER: 20040006
  CFAR: c000000000a13e64 DAR: 0000000000000030 DSISR: 40000000 IRQMASK: 0
  ...
  NIP sysfs_add_link_to_group+0x34/0x94
  LR  iommu_device_link+0x5c/0x118
  Call Trace:
   iommu_init_device+0x26c/0x318 (unreliable)
   iommu_device_link+0x5c/0x118
   iommu_init_device+0xa8/0x318
   iommu_probe_device+0xc0/0x134
   iommu_bus_notifier+0x44/0x104
   notifier_call_chain+0xb8/0x19c
   blocking_notifier_call_chain+0x64/0x98
   bus_notify+0x50/0x7c
   device_add+0x640/0x918
   pci_device_add+0x23c/0x298
   of_create_pci_dev+0x400/0x884
   of_scan_pci_dev+0x124/0x1b0
   __of_scan_bus+0x78/0x18c
   pcibios_scan_phb+0x2a4/0x3b0
   init_phb_dynamic+0xb8/0x110
   dlpar_add_slot+0x170/0x3b8 [rpadlpar_io]
   add_slot_store.part.0+0xb4/0x130 [rpadlpar_io]
   kobj_attr_store+0x2c/0x48
   sysfs_kf_write+0x64/0x78
   kernfs_fop_write_iter+0x1b0/0x290
   vfs_write+0x350/0x4a0
   ksys_write+0x84/0x140
   system_call_exception+0x124/0x330
   system_call_vectored_common+0x15c/0x2ec

Commit a940904 ("powerpc/iommu: Add iommu_ops to report capabilities
and allow blocking domains") broke DLPAR add of PCI devices.

The above added iommu_device structure to pci_controller. During
system boot, PCI devices are discovered and this newly added iommu_device
structure is initialized by a call to iommu_device_register().

During DLPAR add of a PCI device, a new pci_controller structure is
allocated but there are no calls made to iommu_device_register()
interface.

Fix is to register the iommu device during DLPAR add as well.

Fixes: a940904 ("powerpc/iommu: Add iommu_ops to report capabilities and allow blocking domains")
Signed-off-by: Gaurav Batra <gbatra@linux.ibm.com>
Reviewed-by: Brian King <brking@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20240215221833.4817-1-gbatra@linux.ibm.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
anthraxx pushed a commit that referenced this issue Apr 14, 2024
[ Upstream commit 6f6f84a ]

KASAN report null-ptr-deref as follows:

  BUG: KASAN: null-ptr-deref in nfsd_fill_super+0xc6/0xe0 [nfsd]
  Write of size 8 at addr 000000000000005d by task a.out/852

  CPU: 7 PID: 852 Comm: a.out Not tainted 5.18.0-rc7-dirty #66
  Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.14.0-1.fc33 04/01/2014
  Call Trace:
   <TASK>
   dump_stack_lvl+0x34/0x44
   kasan_report+0xab/0x120
   ? nfsd_mkdir+0x71/0x1c0 [nfsd]
   ? nfsd_fill_super+0xc6/0xe0 [nfsd]
   nfsd_fill_super+0xc6/0xe0 [nfsd]
   ? nfsd_mkdir+0x1c0/0x1c0 [nfsd]
   get_tree_keyed+0x8e/0x100
   vfs_get_tree+0x41/0xf0
   __do_sys_fsconfig+0x590/0x670
   ? fscontext_read+0x180/0x180
   ? anon_inode_getfd+0x4f/0x70
   do_syscall_64+0x35/0x80
   entry_SYSCALL_64_after_hwframe+0x44/0xae

This can be reproduce by concurrent operations:
        1. fsopen(nfsd)/fsconfig
        2. insmod/rmmod nfsd

Since the nfsd file system is registered before than nfsd_net allocated,
the caller may get the file_system_type and use the nfsd_net before it
allocated, then null-ptr-deref occurred.

So init_nfsd() should call register_filesystem() last.

Fixes: bd5ae92 ("nfsd: register pernet ops last, unregister first")
Signed-off-by: Zhang Xiaoxu <zhangxiaoxu5@huawei.com>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
anthraxx pushed a commit that referenced this issue May 19, 2024
Florian reported the following kernel NULL pointer dereference issue on
a BCM7250 board:
[    2.829744] Unable to handle kernel NULL pointer dereference at virtual address 0000000c when read
[    2.838740] [0000000c] *pgd=80000000004003, *pmd=00000000
[    2.844178] Internal error: Oops: 206 [#1] SMP ARM
[    2.848990] Modules linked in:
[    2.852061] CPU: 0 PID: 1 Comm: swapper/0 Not tainted 6.8.0-next-20240305-gd95fcdf4961d #66
[    2.860436] Hardware name: Broadcom STB (Flattened Device Tree)
[    2.866371] PC is at brcmnand_read_by_pio+0x180/0x278
[    2.871449] LR is at __wait_for_common+0x9c/0x1b0
[    2.876178] pc : [<c094b6cc>]    lr : [<c0e66310>]    psr: 60000053
[    2.882460] sp : f0811a80  ip : 00000012  fp : 00000000
[    2.887699] r10: 00000000  r9 : 00000000  r8 : c3790000
[    2.892936] r7 : 00000000  r6 : 00000000  r5 : c35db440  r4 : ffe00000
[    2.899479] r3 : f15cb814  r2 : 00000000  r1 : 00000000  r0 : 00000000

The issue only happens when dma mode is disabled or not supported on STB
chip. The pio mode transfer calls brcmnand_read_data_bus function which
dereferences ctrl->soc->read_data_bus. But the soc member in STB chip is
NULL hence triggers the access violation. The function needs to check
the soc pointer first.

Fixes: 546e425 ("mtd: rawnand: brcmnand: Add BCMBCA read data bus interface")

Reported-by: Florian Fainelli <florian.fainelli@broadcom.com>
Tested-by: Florian Fainelli <florian.fainelli@broadcom.com>
Signed-off-by: William Zhang <william.zhang@broadcom.com>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Link: https://lore.kernel.org/linux-mtd/20240320222623.35604-1-william.zhang@broadcom.com
anthraxx pushed a commit that referenced this issue Jun 23, 2024
[ Upstream commit 6f6f84a ]

KASAN report null-ptr-deref as follows:

  BUG: KASAN: null-ptr-deref in nfsd_fill_super+0xc6/0xe0 [nfsd]
  Write of size 8 at addr 000000000000005d by task a.out/852

  CPU: 7 PID: 852 Comm: a.out Not tainted 5.18.0-rc7-dirty #66
  Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.14.0-1.fc33 04/01/2014
  Call Trace:
   <TASK>
   dump_stack_lvl+0x34/0x44
   kasan_report+0xab/0x120
   ? nfsd_mkdir+0x71/0x1c0 [nfsd]
   ? nfsd_fill_super+0xc6/0xe0 [nfsd]
   nfsd_fill_super+0xc6/0xe0 [nfsd]
   ? nfsd_mkdir+0x1c0/0x1c0 [nfsd]
   get_tree_keyed+0x8e/0x100
   vfs_get_tree+0x41/0xf0
   __do_sys_fsconfig+0x590/0x670
   ? fscontext_read+0x180/0x180
   ? anon_inode_getfd+0x4f/0x70
   do_syscall_64+0x35/0x80
   entry_SYSCALL_64_after_hwframe+0x44/0xae

This can be reproduce by concurrent operations:
	1. fsopen(nfsd)/fsconfig
	2. insmod/rmmod nfsd

Since the nfsd file system is registered before than nfsd_net allocated,
the caller may get the file_system_type and use the nfsd_net before it
allocated, then null-ptr-deref occurred.

So init_nfsd() should call register_filesystem() last.

Fixes: bd5ae92 ("nfsd: register pernet ops last, unregister first")
Signed-off-by: Zhang Xiaoxu <zhangxiaoxu5@huawei.com>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
anthraxx pushed a commit that referenced this issue Jul 16, 2024
…b folio

A kernel crash was observed when migrating hugetlb folio:

BUG: kernel NULL pointer dereference, address: 0000000000000008
PGD 0 P4D 0
Oops: Oops: 0002 [#1] PREEMPT SMP NOPTI
CPU: 0 PID: 3435 Comm: bash Not tainted 6.10.0-rc6-00450-g8578ca01f21f #66
RIP: 0010:__folio_undo_large_rmappable+0x70/0xb0
RSP: 0018:ffffb165c98a7b38 EFLAGS: 00000097
RAX: fffffbbc44528090 RBX: 0000000000000000 RCX: 0000000000000000
RDX: ffffa30e000a2800 RSI: 0000000000000246 RDI: ffffa3153ffffcc0
RBP: fffffbbc44528000 R08: 0000000000002371 R09: ffffffffbe4e5868
R10: 0000000000000001 R11: 0000000000000001 R12: ffffa3153ffffcc0
R13: fffffbbc44468000 R14: 0000000000000001 R15: 0000000000000001
FS:  00007f5b3a716740(0000) GS:ffffa3151fc00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000008 CR3: 000000010959a000 CR4: 00000000000006f0
Call Trace:
 <TASK>
 __folio_migrate_mapping+0x59e/0x950
 __migrate_folio.constprop.0+0x5f/0x120
 move_to_new_folio+0xfd/0x250
 migrate_pages+0x383/0xd70
 soft_offline_page+0x2ab/0x7f0
 soft_offline_page_store+0x52/0x90
 kernfs_fop_write_iter+0x12c/0x1d0
 vfs_write+0x380/0x540
 ksys_write+0x64/0xe0
 do_syscall_64+0xb9/0x1d0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f5b3a514887
RSP: 002b:00007ffe138fce68 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 000000000000000c RCX: 00007f5b3a514887
RDX: 000000000000000c RSI: 0000556ab809ee10 RDI: 0000000000000001
RBP: 0000556ab809ee10 R08: 00007f5b3a5d1460 R09: 000000007fffffff
R10: 0000000000000000 R11: 0000000000000246 R12: 000000000000000c
R13: 00007f5b3a61b780 R14: 00007f5b3a617600 R15: 00007f5b3a616a00

It's because hugetlb folio is passed to __folio_undo_large_rmappable()
unexpectedly.  large_rmappable flag is imperceptibly set to hugetlb folio
since commit f6a8dd9 ("hugetlb: convert alloc_buddy_hugetlb_folio to
use a folio").  Then commit be9581e ("mm: fix crashes from deferred
split racing folio migration") makes folio_migrate_mapping() call
folio_undo_large_rmappable() triggering the bug.  Fix this issue by
clearing large_rmappable flag for hugetlb folios.  They don't need that
flag set anyway.

Link: https://lkml.kernel.org/r/20240709120433.4136700-1-linmiaohe@huawei.com
Fixes: f6a8dd9 ("hugetlb: convert alloc_buddy_hugetlb_folio to use a folio")
Fixes: be9581e ("mm: fix crashes from deferred split racing folio migration")
Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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