Allow further restriction of perf events #20

madaidan · 2019-12-25T17:51:28Z

Perf events expose tons of attack surface and have been the cause of many vulnerabilities. linux-hardened restricts these to root by default but this still allows the root user to attack the kernel.

This disallows all access to perf events by all users, including root, when the kernel.perf_event_open sysctl is set to 4 to reduce attack surface.

This keeps the default value as 3 as to not cause too much breakage but users can optionally increase the value.

Bernhard40 · 2019-12-26T13:56:12Z

FYI: there will be upcoming changes related to perf_event_paranoid in linux 5.5: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=da97e18458fb42d7c00fac5fd1c56a3896ec666e

anthraxx · 2020-03-28T15:58:33Z

can we get this adjusted for the latest tree, as there have been perf code changes

madaidan · 2020-03-28T16:57:35Z

Oops... I'm not sure what I did but it broke. I think I'll just resend it.

madaidan · 2020-03-28T17:09:44Z

#31

When experimenting with bpf_send_signal() helper in our production environment (5.2 based), we experienced a deadlock in NMI mode: #5 [ffffc9002219f770] queued_spin_lock_slowpath at ffffffff8110be24 #6 [ffffc9002219f770] _raw_spin_lock_irqsave at ffffffff81a43012 #7 [ffffc9002219f780] try_to_wake_up at ffffffff810e7ecd #8 [ffffc9002219f7e0] signal_wake_up_state at ffffffff810c7b55 #9 [ffffc9002219f7f0] __send_signal at ffffffff810c8602 #10 [ffffc9002219f830] do_send_sig_info at ffffffff810ca31a #11 [ffffc9002219f868] bpf_send_signal at ffffffff8119d227 #12 [ffffc9002219f988] bpf_overflow_handler at ffffffff811d4140 #13 [ffffc9002219f9e0] __perf_event_overflow at ffffffff811d68cf #14 [ffffc9002219fa10] perf_swevent_overflow at ffffffff811d6a09 #15 [ffffc9002219fa38] ___perf_sw_event at ffffffff811e0f47 #16 [ffffc9002219fc30] __schedule at ffffffff81a3e04d #17 [ffffc9002219fc90] schedule at ffffffff81a3e219 #18 [ffffc9002219fca0] futex_wait_queue_me at ffffffff8113d1b9 #19 [ffffc9002219fcd8] futex_wait at ffffffff8113e529 #20 [ffffc9002219fdf0] do_futex at ffffffff8113ffbc #21 [ffffc9002219fec0] __x64_sys_futex at ffffffff81140d1c #22 [ffffc9002219ff38] do_syscall_64 at ffffffff81002602 #23 [ffffc9002219ff50] entry_SYSCALL_64_after_hwframe at ffffffff81c00068 The above call stack is actually very similar to an issue reported by Commit eac9153 ("bpf/stackmap: Fix deadlock with rq_lock in bpf_get_stack()") by Song Liu. The only difference is bpf_send_signal() helper instead of bpf_get_stack() helper. The above deadlock is triggered with a perf_sw_event. Similar to Commit eac9153, the below almost identical reproducer used tracepoint point sched/sched_switch so the issue can be easily caught. /* stress_test.c */ #include <stdio.h> #include <stdlib.h> #include <sys/mman.h> #include <pthread.h> #include <sys/types.h> #include <sys/stat.h> #include <fcntl.h> #define THREAD_COUNT 1000 char *filename; void *worker(void *p) { void *ptr; int fd; char *pptr; fd = open(filename, O_RDONLY); if (fd < 0) return NULL; while (1) { struct timespec ts = {0, 1000 + rand() % 2000}; ptr = mmap(NULL, 4096 * 64, PROT_READ, MAP_PRIVATE, fd, 0); usleep(1); if (ptr == MAP_FAILED) { printf("failed to mmap\n"); break; } munmap(ptr, 4096 * 64); usleep(1); pptr = malloc(1); usleep(1); pptr[0] = 1; usleep(1); free(pptr); usleep(1); nanosleep(&ts, NULL); } close(fd); return NULL; } int main(int argc, char *argv[]) { void *ptr; int i; pthread_t threads[THREAD_COUNT]; if (argc < 2) return 0; filename = argv[1]; for (i = 0; i < THREAD_COUNT; i++) { if (pthread_create(threads + i, NULL, worker, NULL)) { fprintf(stderr, "Error creating thread\n"); return 0; } } for (i = 0; i < THREAD_COUNT; i++) pthread_join(threads[i], NULL); return 0; } and the following command: 1. run `stress_test /bin/ls` in one windown 2. hack bcc trace.py with the following change: --- a/tools/trace.py +++ b/tools/trace.py @@ -513,6 +513,7 @@ BPF_PERF_OUTPUT(%s); __data.tgid = __tgid; __data.pid = __pid; bpf_get_current_comm(&__data.comm, sizeof(__data.comm)); + bpf_send_signal(10); %s %s %s.perf_submit(%s, &__data, sizeof(__data)); 3. in a different window run ./trace.py -p $(pidof stress_test) t:sched:sched_switch The deadlock can be reproduced in our production system. Similar to Song's fix, the fix is to delay sending signal if irqs is disabled to avoid deadlocks involving with rq_lock. With this change, my above stress-test in our production system won't cause deadlock any more. I also implemented a scale-down version of reproducer in the selftest (a subsequent commit). With latest bpf-next, it complains for the following potential deadlock. [ 32.832450] -> #1 (&p->pi_lock){-.-.}: [ 32.833100] _raw_spin_lock_irqsave+0x44/0x80 [ 32.833696] task_rq_lock+0x2c/0xa0 [ 32.834182] task_sched_runtime+0x59/0xd0 [ 32.834721] thread_group_cputime+0x250/0x270 [ 32.835304] thread_group_cputime_adjusted+0x2e/0x70 [ 32.835959] do_task_stat+0x8a7/0xb80 [ 32.836461] proc_single_show+0x51/0xb0 ... [ 32.839512] -> #0 (&(&sighand->siglock)->rlock){....}: [ 32.840275] __lock_acquire+0x1358/0x1a20 [ 32.840826] lock_acquire+0xc7/0x1d0 [ 32.841309] _raw_spin_lock_irqsave+0x44/0x80 [ 32.841916] __lock_task_sighand+0x79/0x160 [ 32.842465] do_send_sig_info+0x35/0x90 [ 32.842977] bpf_send_signal+0xa/0x10 [ 32.843464] bpf_prog_bc13ed9e4d3163e3_send_signal_tp_sched+0x465/0x1000 [ 32.844301] trace_call_bpf+0x115/0x270 [ 32.844809] perf_trace_run_bpf_submit+0x4a/0xc0 [ 32.845411] perf_trace_sched_switch+0x10f/0x180 [ 32.846014] __schedule+0x45d/0x880 [ 32.846483] schedule+0x5f/0xd0 ... [ 32.853148] Chain exists of: [ 32.853148] &(&sighand->siglock)->rlock --> &p->pi_lock --> &rq->lock [ 32.853148] [ 32.854451] Possible unsafe locking scenario: [ 32.854451] [ 32.855173] CPU0 CPU1 [ 32.855745] ---- ---- [ 32.856278] lock(&rq->lock); [ 32.856671] lock(&p->pi_lock); [ 32.857332] lock(&rq->lock); [ 32.857999] lock(&(&sighand->siglock)->rlock); Deadlock happens on CPU0 when it tries to acquire &sighand->siglock but it has been held by CPU1 and CPU1 tries to grab &rq->lock and cannot get it. This is not exactly the callstack in our production environment, but sympotom is similar and both locks are using spin_lock_irqsave() to acquire the lock, and both involves rq_lock. The fix to delay sending signal when irq is disabled also fixed this issue. Signed-off-by: Yonghong Song <yhs@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Cc: Song Liu <songliubraving@fb.com> Link: https://lore.kernel.org/bpf/20200304191104.2796501-1-yhs@fb.com

[ Upstream commit 1bc7896 ] When experimenting with bpf_send_signal() helper in our production environment (5.2 based), we experienced a deadlock in NMI mode: #5 [ffffc9002219f770] queued_spin_lock_slowpath at ffffffff8110be24 #6 [ffffc9002219f770] _raw_spin_lock_irqsave at ffffffff81a43012 #7 [ffffc9002219f780] try_to_wake_up at ffffffff810e7ecd #8 [ffffc9002219f7e0] signal_wake_up_state at ffffffff810c7b55 #9 [ffffc9002219f7f0] __send_signal at ffffffff810c8602 #10 [ffffc9002219f830] do_send_sig_info at ffffffff810ca31a #11 [ffffc9002219f868] bpf_send_signal at ffffffff8119d227 #12 [ffffc9002219f988] bpf_overflow_handler at ffffffff811d4140 #13 [ffffc9002219f9e0] __perf_event_overflow at ffffffff811d68cf #14 [ffffc9002219fa10] perf_swevent_overflow at ffffffff811d6a09 #15 [ffffc9002219fa38] ___perf_sw_event at ffffffff811e0f47 #16 [ffffc9002219fc30] __schedule at ffffffff81a3e04d #17 [ffffc9002219fc90] schedule at ffffffff81a3e219 #18 [ffffc9002219fca0] futex_wait_queue_me at ffffffff8113d1b9 #19 [ffffc9002219fcd8] futex_wait at ffffffff8113e529 #20 [ffffc9002219fdf0] do_futex at ffffffff8113ffbc #21 [ffffc9002219fec0] __x64_sys_futex at ffffffff81140d1c #22 [ffffc9002219ff38] do_syscall_64 at ffffffff81002602 #23 [ffffc9002219ff50] entry_SYSCALL_64_after_hwframe at ffffffff81c00068 The above call stack is actually very similar to an issue reported by Commit eac9153 ("bpf/stackmap: Fix deadlock with rq_lock in bpf_get_stack()") by Song Liu. The only difference is bpf_send_signal() helper instead of bpf_get_stack() helper. The above deadlock is triggered with a perf_sw_event. Similar to Commit eac9153, the below almost identical reproducer used tracepoint point sched/sched_switch so the issue can be easily caught. /* stress_test.c */ #include <stdio.h> #include <stdlib.h> #include <sys/mman.h> #include <pthread.h> #include <sys/types.h> #include <sys/stat.h> #include <fcntl.h> #define THREAD_COUNT 1000 char *filename; void *worker(void *p) { void *ptr; int fd; char *pptr; fd = open(filename, O_RDONLY); if (fd < 0) return NULL; while (1) { struct timespec ts = {0, 1000 + rand() % 2000}; ptr = mmap(NULL, 4096 * 64, PROT_READ, MAP_PRIVATE, fd, 0); usleep(1); if (ptr == MAP_FAILED) { printf("failed to mmap\n"); break; } munmap(ptr, 4096 * 64); usleep(1); pptr = malloc(1); usleep(1); pptr[0] = 1; usleep(1); free(pptr); usleep(1); nanosleep(&ts, NULL); } close(fd); return NULL; } int main(int argc, char *argv[]) { void *ptr; int i; pthread_t threads[THREAD_COUNT]; if (argc < 2) return 0; filename = argv[1]; for (i = 0; i < THREAD_COUNT; i++) { if (pthread_create(threads + i, NULL, worker, NULL)) { fprintf(stderr, "Error creating thread\n"); return 0; } } for (i = 0; i < THREAD_COUNT; i++) pthread_join(threads[i], NULL); return 0; } and the following command: 1. run `stress_test /bin/ls` in one windown 2. hack bcc trace.py with the following change: # --- a/tools/trace.py # +++ b/tools/trace.py @@ -513,6 +513,7 @@ BPF_PERF_OUTPUT(%s); __data.tgid = __tgid; __data.pid = __pid; bpf_get_current_comm(&__data.comm, sizeof(__data.comm)); + bpf_send_signal(10); %s %s %s.perf_submit(%s, &__data, sizeof(__data)); 3. in a different window run ./trace.py -p $(pidof stress_test) t:sched:sched_switch The deadlock can be reproduced in our production system. Similar to Song's fix, the fix is to delay sending signal if irqs is disabled to avoid deadlocks involving with rq_lock. With this change, my above stress-test in our production system won't cause deadlock any more. I also implemented a scale-down version of reproducer in the selftest (a subsequent commit). With latest bpf-next, it complains for the following potential deadlock. [ 32.832450] -> #1 (&p->pi_lock){-.-.}: [ 32.833100] _raw_spin_lock_irqsave+0x44/0x80 [ 32.833696] task_rq_lock+0x2c/0xa0 [ 32.834182] task_sched_runtime+0x59/0xd0 [ 32.834721] thread_group_cputime+0x250/0x270 [ 32.835304] thread_group_cputime_adjusted+0x2e/0x70 [ 32.835959] do_task_stat+0x8a7/0xb80 [ 32.836461] proc_single_show+0x51/0xb0 ... [ 32.839512] -> #0 (&(&sighand->siglock)->rlock){....}: [ 32.840275] __lock_acquire+0x1358/0x1a20 [ 32.840826] lock_acquire+0xc7/0x1d0 [ 32.841309] _raw_spin_lock_irqsave+0x44/0x80 [ 32.841916] __lock_task_sighand+0x79/0x160 [ 32.842465] do_send_sig_info+0x35/0x90 [ 32.842977] bpf_send_signal+0xa/0x10 [ 32.843464] bpf_prog_bc13ed9e4d3163e3_send_signal_tp_sched+0x465/0x1000 [ 32.844301] trace_call_bpf+0x115/0x270 [ 32.844809] perf_trace_run_bpf_submit+0x4a/0xc0 [ 32.845411] perf_trace_sched_switch+0x10f/0x180 [ 32.846014] __schedule+0x45d/0x880 [ 32.846483] schedule+0x5f/0xd0 ... [ 32.853148] Chain exists of: [ 32.853148] &(&sighand->siglock)->rlock --> &p->pi_lock --> &rq->lock [ 32.853148] [ 32.854451] Possible unsafe locking scenario: [ 32.854451] [ 32.855173] CPU0 CPU1 [ 32.855745] ---- ---- [ 32.856278] lock(&rq->lock); [ 32.856671] lock(&p->pi_lock); [ 32.857332] lock(&rq->lock); [ 32.857999] lock(&(&sighand->siglock)->rlock); Deadlock happens on CPU0 when it tries to acquire &sighand->siglock but it has been held by CPU1 and CPU1 tries to grab &rq->lock and cannot get it. This is not exactly the callstack in our production environment, but sympotom is similar and both locks are using spin_lock_irqsave() to acquire the lock, and both involves rq_lock. The fix to delay sending signal when irq is disabled also fixed this issue. Signed-off-by: Yonghong Song <yhs@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Cc: Song Liu <songliubraving@fb.com> Link: https://lore.kernel.org/bpf/20200304191104.2796501-1-yhs@fb.com Signed-off-by: Sasha Levin <sashal@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

[ no upstream commit ] Switch the comparison, so that is_branch_taken() will recognize that below branch is never taken: [...] 17: [...] R1_w=inv0 [...] R8_w=inv(id=0,smin_value=-2147483648,smax_value=-1,umin_value=18446744071562067968,var_off=(0xffffffff80000000; 0x7fffffff)) [...] 17: (67) r8 <<= 32 18: [...] R8_w=inv(id=0,smax_value=-4294967296,umin_value=9223372036854775808,umax_value=18446744069414584320,var_off=(0x8000000000000000; 0x7fffffff00000000)) [...] 18: (c7) r8 s>>= 32 19: [...] R8_w=inv(id=0,smin_value=-2147483648,smax_value=-1,umin_value=18446744071562067968,var_off=(0xffffffff80000000; 0x7fffffff)) [...] 19: (6d) if r1 s> r8 goto pc+16 [...] R1_w=inv0 [...] R8_w=inv(id=0,smin_value=-2147483648,smax_value=-1,umin_value=18446744071562067968,var_off=(0xffffffff80000000; 0x7fffffff)) [...] [...] Currently we check for is_branch_taken() only if either K is source, or source is a scalar value that is const. For upstream it would be good to extend this properly to check whether dst is const and src not. For the sake of the test_verifier, it is probably not needed here: # ./test_verifier 101 #101/p bpf_get_stack return R0 within range OK Summary: 1 PASSED, 0 SKIPPED, 0 FAILED I haven't seen this issue in test_progs* though, they are passing fine: # ./test_progs-no_alu32 -t get_stack Switching to flavor 'no_alu32' subdirectory... #20 get_stack_raw_tp:OK Summary: 1/0 PASSED, 0 SKIPPED, 0 FAILED # ./test_progs -t get_stack #20 get_stack_raw_tp:OK Summary: 1/0 PASSED, 0 SKIPPED, 0 FAILED Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Alexei Starovoitov <ast@kernel.org> Acked-by: John Fastabend <john.fastabend@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

[ Upstream commit e24c644 ] I compiled with AddressSanitizer and I had these memory leaks while I was using the tep_parse_format function: Direct leak of 28 byte(s) in 4 object(s) allocated from: #0 0x7fb07db49ffe in __interceptor_realloc (/lib/x86_64-linux-gnu/libasan.so.5+0x10dffe) #1 0x7fb07a724228 in extend_token /home/pduplessis/repo/linux/tools/lib/traceevent/event-parse.c:985 #2 0x7fb07a724c21 in __read_token /home/pduplessis/repo/linux/tools/lib/traceevent/event-parse.c:1140 #3 0x7fb07a724f78 in read_token /home/pduplessis/repo/linux/tools/lib/traceevent/event-parse.c:1206 #4 0x7fb07a725191 in __read_expect_type /home/pduplessis/repo/linux/tools/lib/traceevent/event-parse.c:1291 #5 0x7fb07a7251df in read_expect_type /home/pduplessis/repo/linux/tools/lib/traceevent/event-parse.c:1299 #6 0x7fb07a72e6c8 in process_dynamic_array_len /home/pduplessis/repo/linux/tools/lib/traceevent/event-parse.c:2849 #7 0x7fb07a7304b8 in process_function /home/pduplessis/repo/linux/tools/lib/traceevent/event-parse.c:3161 #8 0x7fb07a730900 in process_arg_token /home/pduplessis/repo/linux/tools/lib/traceevent/event-parse.c:3207 #9 0x7fb07a727c0b in process_arg /home/pduplessis/repo/linux/tools/lib/traceevent/event-parse.c:1786 #10 0x7fb07a731080 in event_read_print_args /home/pduplessis/repo/linux/tools/lib/traceevent/event-parse.c:3285 #11 0x7fb07a731722 in event_read_print /home/pduplessis/repo/linux/tools/lib/traceevent/event-parse.c:3369 #12 0x7fb07a740054 in __tep_parse_format /home/pduplessis/repo/linux/tools/lib/traceevent/event-parse.c:6335 #13 0x7fb07a74047a in __parse_event /home/pduplessis/repo/linux/tools/lib/traceevent/event-parse.c:6389 #14 0x7fb07a740536 in tep_parse_format /home/pduplessis/repo/linux/tools/lib/traceevent/event-parse.c:6431 #15 0x7fb07a785acf in parse_event ../../../src/fs-src/fs.c:251 #16 0x7fb07a785ccd in parse_systems ../../../src/fs-src/fs.c:284 #17 0x7fb07a786fb3 in read_metadata ../../../src/fs-src/fs.c:593 #18 0x7fb07a78760e in ftrace_fs_source_init ../../../src/fs-src/fs.c:727 #19 0x7fb07d90c19c in add_component_with_init_method_data ../../../../src/lib/graph/graph.c:1048 #20 0x7fb07d90c87b in add_source_component_with_initialize_method_data ../../../../src/lib/graph/graph.c:1127 #21 0x7fb07d90c92a in bt_graph_add_source_component ../../../../src/lib/graph/graph.c:1152 #22 0x55db11aa632e in cmd_run_ctx_create_components_from_config_components ../../../src/cli/babeltrace2.c:2252 #23 0x55db11aa6fda in cmd_run_ctx_create_components ../../../src/cli/babeltrace2.c:2347 #24 0x55db11aa780c in cmd_run ../../../src/cli/babeltrace2.c:2461 #25 0x55db11aa8a7d in main ../../../src/cli/babeltrace2.c:2673 #26 0x7fb07d5460b2 in __libc_start_main (/lib/x86_64-linux-gnu/libc.so.6+0x270b2) The token variable in the process_dynamic_array_len function is allocated in the read_expect_type function, but is not freed before calling the read_token function. Free the token variable before calling read_token in order to plug the leak. Signed-off-by: Philippe Duplessis-Guindon <pduplessis@efficios.com> Reviewed-by: Steven Rostedt (VMware) <rostedt@goodmis.org> Link: https://lore.kernel.org/linux-trace-devel/20200730150236.5392-1-pduplessis@efficios.com Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com> Signed-off-by: Sasha Levin <sashal@kernel.org>

[ Upstream commit ab0db04 ] When running with -o enospc_debug you can get the following splat if one of the dump_space_info's trip ====================================================== WARNING: possible circular locking dependency detected 5.8.0-rc5+ #20 Tainted: G OE ------------------------------------------------------ dd/563090 is trying to acquire lock: ffff9e7dbf4f1e18 (&ctl->tree_lock){+.+.}-{2:2}, at: btrfs_dump_free_space+0x2b/0xa0 [btrfs] but task is already holding lock: ffff9e7e2284d428 (&cache->lock){+.+.}-{2:2}, at: btrfs_dump_space_info+0xaa/0x120 [btrfs] which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #3 (&cache->lock){+.+.}-{2:2}: _raw_spin_lock+0x25/0x30 btrfs_add_reserved_bytes+0x3c/0x3c0 [btrfs] find_free_extent+0x7ef/0x13b0 [btrfs] btrfs_reserve_extent+0x9b/0x180 [btrfs] btrfs_alloc_tree_block+0xc1/0x340 [btrfs] alloc_tree_block_no_bg_flush+0x4a/0x60 [btrfs] __btrfs_cow_block+0x122/0x530 [btrfs] btrfs_cow_block+0x106/0x210 [btrfs] commit_cowonly_roots+0x55/0x300 [btrfs] btrfs_commit_transaction+0x4ed/0xac0 [btrfs] sync_filesystem+0x74/0x90 generic_shutdown_super+0x22/0x100 kill_anon_super+0x14/0x30 btrfs_kill_super+0x12/0x20 [btrfs] deactivate_locked_super+0x36/0x70 cleanup_mnt+0x104/0x160 task_work_run+0x5f/0x90 __prepare_exit_to_usermode+0x1bd/0x1c0 do_syscall_64+0x5e/0xb0 entry_SYSCALL_64_after_hwframe+0x44/0xa9 -> #2 (&space_info->lock){+.+.}-{2:2}: _raw_spin_lock+0x25/0x30 btrfs_block_rsv_release+0x1a6/0x3f0 [btrfs] btrfs_inode_rsv_release+0x4f/0x170 [btrfs] btrfs_clear_delalloc_extent+0x155/0x480 [btrfs] clear_state_bit+0x81/0x1a0 [btrfs] __clear_extent_bit+0x25c/0x5d0 [btrfs] clear_extent_bit+0x15/0x20 [btrfs] btrfs_invalidatepage+0x2b7/0x3c0 [btrfs] truncate_cleanup_page+0x47/0xe0 truncate_inode_pages_range+0x238/0x840 truncate_pagecache+0x44/0x60 btrfs_setattr+0x202/0x5e0 [btrfs] notify_change+0x33b/0x490 do_truncate+0x76/0xd0 path_openat+0x687/0xa10 do_filp_open+0x91/0x100 do_sys_openat2+0x215/0x2d0 do_sys_open+0x44/0x80 do_syscall_64+0x52/0xb0 entry_SYSCALL_64_after_hwframe+0x44/0xa9 -> #1 (&tree->lock#2){+.+.}-{2:2}: _raw_spin_lock+0x25/0x30 find_first_extent_bit+0x32/0x150 [btrfs] write_pinned_extent_entries.isra.0+0xc5/0x100 [btrfs] __btrfs_write_out_cache+0x172/0x480 [btrfs] btrfs_write_out_cache+0x7a/0xf0 [btrfs] btrfs_write_dirty_block_groups+0x286/0x3b0 [btrfs] commit_cowonly_roots+0x245/0x300 [btrfs] btrfs_commit_transaction+0x4ed/0xac0 [btrfs] close_ctree+0xf9/0x2f5 [btrfs] generic_shutdown_super+0x6c/0x100 kill_anon_super+0x14/0x30 btrfs_kill_super+0x12/0x20 [btrfs] deactivate_locked_super+0x36/0x70 cleanup_mnt+0x104/0x160 task_work_run+0x5f/0x90 __prepare_exit_to_usermode+0x1bd/0x1c0 do_syscall_64+0x5e/0xb0 entry_SYSCALL_64_after_hwframe+0x44/0xa9 -> #0 (&ctl->tree_lock){+.+.}-{2:2}: __lock_acquire+0x1240/0x2460 lock_acquire+0xab/0x360 _raw_spin_lock+0x25/0x30 btrfs_dump_free_space+0x2b/0xa0 [btrfs] btrfs_dump_space_info+0xf4/0x120 [btrfs] btrfs_reserve_extent+0x176/0x180 [btrfs] __btrfs_prealloc_file_range+0x145/0x550 [btrfs] cache_save_setup+0x28d/0x3b0 [btrfs] btrfs_start_dirty_block_groups+0x1fc/0x4f0 [btrfs] btrfs_commit_transaction+0xcc/0xac0 [btrfs] btrfs_alloc_data_chunk_ondemand+0x162/0x4c0 [btrfs] btrfs_check_data_free_space+0x4c/0xa0 [btrfs] btrfs_buffered_write.isra.0+0x19b/0x740 [btrfs] btrfs_file_write_iter+0x3cf/0x610 [btrfs] new_sync_write+0x11e/0x1b0 vfs_write+0x1c9/0x200 ksys_write+0x68/0xe0 do_syscall_64+0x52/0xb0 entry_SYSCALL_64_after_hwframe+0x44/0xa9 other info that might help us debug this: Chain exists of: &ctl->tree_lock --> &space_info->lock --> &cache->lock Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&cache->lock); lock(&space_info->lock); lock(&cache->lock); lock(&ctl->tree_lock); *** DEADLOCK *** 6 locks held by dd/563090: #0: ffff9e7e21d18448 (sb_writers#14){.+.+}-{0:0}, at: vfs_write+0x195/0x200 #1: ffff9e7dd0410ed8 (&sb->s_type->i_mutex_key#19){++++}-{3:3}, at: btrfs_file_write_iter+0x86/0x610 [btrfs] #2: ffff9e7e21d18638 (sb_internal#2){.+.+}-{0:0}, at: start_transaction+0x40b/0x5b0 [btrfs] #3: ffff9e7e1f05d688 (&cur_trans->cache_write_mutex){+.+.}-{3:3}, at: btrfs_start_dirty_block_groups+0x158/0x4f0 [btrfs] #4: ffff9e7e2284ddb8 (&space_info->groups_sem){++++}-{3:3}, at: btrfs_dump_space_info+0x69/0x120 [btrfs] #5: ffff9e7e2284d428 (&cache->lock){+.+.}-{2:2}, at: btrfs_dump_space_info+0xaa/0x120 [btrfs] stack backtrace: CPU: 3 PID: 563090 Comm: dd Tainted: G OE 5.8.0-rc5+ #20 Hardware name: To Be Filled By O.E.M. To Be Filled By O.E.M./890FX Deluxe5, BIOS P1.40 05/03/2011 Call Trace: dump_stack+0x96/0xd0 check_noncircular+0x162/0x180 __lock_acquire+0x1240/0x2460 ? wake_up_klogd.part.0+0x30/0x40 lock_acquire+0xab/0x360 ? btrfs_dump_free_space+0x2b/0xa0 [btrfs] _raw_spin_lock+0x25/0x30 ? btrfs_dump_free_space+0x2b/0xa0 [btrfs] btrfs_dump_free_space+0x2b/0xa0 [btrfs] btrfs_dump_space_info+0xf4/0x120 [btrfs] btrfs_reserve_extent+0x176/0x180 [btrfs] __btrfs_prealloc_file_range+0x145/0x550 [btrfs] ? btrfs_qgroup_reserve_data+0x1d/0x60 [btrfs] cache_save_setup+0x28d/0x3b0 [btrfs] btrfs_start_dirty_block_groups+0x1fc/0x4f0 [btrfs] btrfs_commit_transaction+0xcc/0xac0 [btrfs] ? start_transaction+0xe0/0x5b0 [btrfs] btrfs_alloc_data_chunk_ondemand+0x162/0x4c0 [btrfs] btrfs_check_data_free_space+0x4c/0xa0 [btrfs] btrfs_buffered_write.isra.0+0x19b/0x740 [btrfs] ? ktime_get_coarse_real_ts64+0xa8/0xd0 ? trace_hardirqs_on+0x1c/0xe0 btrfs_file_write_iter+0x3cf/0x610 [btrfs] new_sync_write+0x11e/0x1b0 vfs_write+0x1c9/0x200 ksys_write+0x68/0xe0 do_syscall_64+0x52/0xb0 entry_SYSCALL_64_after_hwframe+0x44/0xa9 This is because we're holding the block_group->lock while trying to dump the free space cache. However we don't need this lock, we just need it to read the values for the printk, so move the free space cache dumping outside of the block group lock. Signed-off-by: Josef Bacik <josef@toxicpanda.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Sasha Levin <sashal@kernel.org>

[ Upstream commit e24c644 ] I compiled with AddressSanitizer and I had these memory leaks while I was using the tep_parse_format function: Direct leak of 28 byte(s) in 4 object(s) allocated from: #0 0x7fb07db49ffe in __interceptor_realloc (/lib/x86_64-linux-gnu/libasan.so.5+0x10dffe) #1 0x7fb07a724228 in extend_token /home/pduplessis/repo/linux/tools/lib/traceevent/event-parse.c:985 #2 0x7fb07a724c21 in __read_token /home/pduplessis/repo/linux/tools/lib/traceevent/event-parse.c:1140 #3 0x7fb07a724f78 in read_token /home/pduplessis/repo/linux/tools/lib/traceevent/event-parse.c:1206 #4 0x7fb07a725191 in __read_expect_type /home/pduplessis/repo/linux/tools/lib/traceevent/event-parse.c:1291 #5 0x7fb07a7251df in read_expect_type /home/pduplessis/repo/linux/tools/lib/traceevent/event-parse.c:1299 #6 0x7fb07a72e6c8 in process_dynamic_array_len /home/pduplessis/repo/linux/tools/lib/traceevent/event-parse.c:2849 #7 0x7fb07a7304b8 in process_function /home/pduplessis/repo/linux/tools/lib/traceevent/event-parse.c:3161 #8 0x7fb07a730900 in process_arg_token /home/pduplessis/repo/linux/tools/lib/traceevent/event-parse.c:3207 #9 0x7fb07a727c0b in process_arg /home/pduplessis/repo/linux/tools/lib/traceevent/event-parse.c:1786 #10 0x7fb07a731080 in event_read_print_args /home/pduplessis/repo/linux/tools/lib/traceevent/event-parse.c:3285 #11 0x7fb07a731722 in event_read_print /home/pduplessis/repo/linux/tools/lib/traceevent/event-parse.c:3369 #12 0x7fb07a740054 in __tep_parse_format /home/pduplessis/repo/linux/tools/lib/traceevent/event-parse.c:6335 #13 0x7fb07a74047a in __parse_event /home/pduplessis/repo/linux/tools/lib/traceevent/event-parse.c:6389 #14 0x7fb07a740536 in tep_parse_format /home/pduplessis/repo/linux/tools/lib/traceevent/event-parse.c:6431 #15 0x7fb07a785acf in parse_event ../../../src/fs-src/fs.c:251 #16 0x7fb07a785ccd in parse_systems ../../../src/fs-src/fs.c:284 #17 0x7fb07a786fb3 in read_metadata ../../../src/fs-src/fs.c:593 #18 0x7fb07a78760e in ftrace_fs_source_init ../../../src/fs-src/fs.c:727 #19 0x7fb07d90c19c in add_component_with_init_method_data ../../../../src/lib/graph/graph.c:1048 #20 0x7fb07d90c87b in add_source_component_with_initialize_method_data ../../../../src/lib/graph/graph.c:1127 #21 0x7fb07d90c92a in bt_graph_add_source_component ../../../../src/lib/graph/graph.c:1152 #22 0x55db11aa632e in cmd_run_ctx_create_components_from_config_components ../../../src/cli/babeltrace2.c:2252 #23 0x55db11aa6fda in cmd_run_ctx_create_components ../../../src/cli/babeltrace2.c:2347 #24 0x55db11aa780c in cmd_run ../../../src/cli/babeltrace2.c:2461 #25 0x55db11aa8a7d in main ../../../src/cli/babeltrace2.c:2673 #26 0x7fb07d5460b2 in __libc_start_main (/lib/x86_64-linux-gnu/libc.so.6+0x270b2) The token variable in the process_dynamic_array_len function is allocated in the read_expect_type function, but is not freed before calling the read_token function. Free the token variable before calling read_token in order to plug the leak. Signed-off-by: Philippe Duplessis-Guindon <pduplessis@efficios.com> Reviewed-by: Steven Rostedt (VMware) <rostedt@goodmis.org> Link: https://lore.kernel.org/linux-trace-devel/20200730150236.5392-1-pduplessis@efficios.com Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com> Signed-off-by: Sasha Levin <sashal@kernel.org>

commit 01d01ca upstream. We are currently getting this lockdep splat in btrfs/161: ====================================================== WARNING: possible circular locking dependency detected 5.8.0-rc5+ #20 Tainted: G E ------------------------------------------------------ mount/678048 is trying to acquire lock: ffff9b769f15b6e0 (&fs_devs->device_list_mutex){+.+.}-{3:3}, at: clone_fs_devices+0x4d/0x170 [btrfs] but task is already holding lock: ffff9b76abdb08d0 (&fs_info->chunk_mutex){+.+.}-{3:3}, at: btrfs_read_chunk_tree+0x6a/0x800 [btrfs] which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #1 (&fs_info->chunk_mutex){+.+.}-{3:3}: __mutex_lock+0x8b/0x8f0 btrfs_init_new_device+0x2d2/0x1240 [btrfs] btrfs_ioctl+0x1de/0x2d20 [btrfs] ksys_ioctl+0x87/0xc0 __x64_sys_ioctl+0x16/0x20 do_syscall_64+0x52/0xb0 entry_SYSCALL_64_after_hwframe+0x44/0xa9 -> #0 (&fs_devs->device_list_mutex){+.+.}-{3:3}: __lock_acquire+0x1240/0x2460 lock_acquire+0xab/0x360 __mutex_lock+0x8b/0x8f0 clone_fs_devices+0x4d/0x170 [btrfs] btrfs_read_chunk_tree+0x330/0x800 [btrfs] open_ctree+0xb7c/0x18ce [btrfs] btrfs_mount_root.cold+0x13/0xfa [btrfs] legacy_get_tree+0x30/0x50 vfs_get_tree+0x28/0xc0 fc_mount+0xe/0x40 vfs_kern_mount.part.0+0x71/0x90 btrfs_mount+0x13b/0x3e0 [btrfs] legacy_get_tree+0x30/0x50 vfs_get_tree+0x28/0xc0 do_mount+0x7de/0xb30 __x64_sys_mount+0x8e/0xd0 do_syscall_64+0x52/0xb0 entry_SYSCALL_64_after_hwframe+0x44/0xa9 other info that might help us debug this: Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&fs_info->chunk_mutex); lock(&fs_devs->device_list_mutex); lock(&fs_info->chunk_mutex); lock(&fs_devs->device_list_mutex); *** DEADLOCK *** 3 locks held by mount/678048: #0: ffff9b75ff5fb0e0 (&type->s_umount_key#63/1){+.+.}-{3:3}, at: alloc_super+0xb5/0x380 #1: ffffffffc0c2fbc8 (uuid_mutex){+.+.}-{3:3}, at: btrfs_read_chunk_tree+0x54/0x800 [btrfs] #2: ffff9b76abdb08d0 (&fs_info->chunk_mutex){+.+.}-{3:3}, at: btrfs_read_chunk_tree+0x6a/0x800 [btrfs] stack backtrace: CPU: 2 PID: 678048 Comm: mount Tainted: G E 5.8.0-rc5+ #20 Hardware name: To Be Filled By O.E.M. To Be Filled By O.E.M./890FX Deluxe5, BIOS P1.40 05/03/2011 Call Trace: dump_stack+0x96/0xd0 check_noncircular+0x162/0x180 __lock_acquire+0x1240/0x2460 ? asm_sysvec_apic_timer_interrupt+0x12/0x20 lock_acquire+0xab/0x360 ? clone_fs_devices+0x4d/0x170 [btrfs] __mutex_lock+0x8b/0x8f0 ? clone_fs_devices+0x4d/0x170 [btrfs] ? rcu_read_lock_sched_held+0x52/0x60 ? cpumask_next+0x16/0x20 ? module_assert_mutex_or_preempt+0x14/0x40 ? __module_address+0x28/0xf0 ? clone_fs_devices+0x4d/0x170 [btrfs] ? static_obj+0x4f/0x60 ? lockdep_init_map_waits+0x43/0x200 ? clone_fs_devices+0x4d/0x170 [btrfs] clone_fs_devices+0x4d/0x170 [btrfs] btrfs_read_chunk_tree+0x330/0x800 [btrfs] open_ctree+0xb7c/0x18ce [btrfs] ? super_setup_bdi_name+0x79/0xd0 btrfs_mount_root.cold+0x13/0xfa [btrfs] ? vfs_parse_fs_string+0x84/0xb0 ? rcu_read_lock_sched_held+0x52/0x60 ? kfree+0x2b5/0x310 legacy_get_tree+0x30/0x50 vfs_get_tree+0x28/0xc0 fc_mount+0xe/0x40 vfs_kern_mount.part.0+0x71/0x90 btrfs_mount+0x13b/0x3e0 [btrfs] ? cred_has_capability+0x7c/0x120 ? rcu_read_lock_sched_held+0x52/0x60 ? legacy_get_tree+0x30/0x50 legacy_get_tree+0x30/0x50 vfs_get_tree+0x28/0xc0 do_mount+0x7de/0xb30 ? memdup_user+0x4e/0x90 __x64_sys_mount+0x8e/0xd0 do_syscall_64+0x52/0xb0 entry_SYSCALL_64_after_hwframe+0x44/0xa9 This is because btrfs_read_chunk_tree() can come upon DEV_EXTENT's and then read the device, which takes the device_list_mutex. The device_list_mutex needs to be taken before the chunk_mutex, so this is a problem. We only really need the chunk mutex around adding the chunk, so move the mutex around read_one_chunk. An argument could be made that we don't even need the chunk_mutex here as it's during mount, and we are protected by various other locks. However we already have special rules for ->device_list_mutex, and I'd rather not have another special case for ->chunk_mutex. CC: stable@vger.kernel.org # 4.19+ Reviewed-by: Anand Jain <anand.jain@oracle.com> Signed-off-by: Josef Bacik <josef@toxicpanda.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

[ Upstream commit ab0db04 ] When running with -o enospc_debug you can get the following splat if one of the dump_space_info's trip ====================================================== WARNING: possible circular locking dependency detected 5.8.0-rc5+ #20 Tainted: G OE ------------------------------------------------------ dd/563090 is trying to acquire lock: ffff9e7dbf4f1e18 (&ctl->tree_lock){+.+.}-{2:2}, at: btrfs_dump_free_space+0x2b/0xa0 [btrfs] but task is already holding lock: ffff9e7e2284d428 (&cache->lock){+.+.}-{2:2}, at: btrfs_dump_space_info+0xaa/0x120 [btrfs] which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #3 (&cache->lock){+.+.}-{2:2}: _raw_spin_lock+0x25/0x30 btrfs_add_reserved_bytes+0x3c/0x3c0 [btrfs] find_free_extent+0x7ef/0x13b0 [btrfs] btrfs_reserve_extent+0x9b/0x180 [btrfs] btrfs_alloc_tree_block+0xc1/0x340 [btrfs] alloc_tree_block_no_bg_flush+0x4a/0x60 [btrfs] __btrfs_cow_block+0x122/0x530 [btrfs] btrfs_cow_block+0x106/0x210 [btrfs] commit_cowonly_roots+0x55/0x300 [btrfs] btrfs_commit_transaction+0x4ed/0xac0 [btrfs] sync_filesystem+0x74/0x90 generic_shutdown_super+0x22/0x100 kill_anon_super+0x14/0x30 btrfs_kill_super+0x12/0x20 [btrfs] deactivate_locked_super+0x36/0x70 cleanup_mnt+0x104/0x160 task_work_run+0x5f/0x90 __prepare_exit_to_usermode+0x1bd/0x1c0 do_syscall_64+0x5e/0xb0 entry_SYSCALL_64_after_hwframe+0x44/0xa9 -> #2 (&space_info->lock){+.+.}-{2:2}: _raw_spin_lock+0x25/0x30 btrfs_block_rsv_release+0x1a6/0x3f0 [btrfs] btrfs_inode_rsv_release+0x4f/0x170 [btrfs] btrfs_clear_delalloc_extent+0x155/0x480 [btrfs] clear_state_bit+0x81/0x1a0 [btrfs] __clear_extent_bit+0x25c/0x5d0 [btrfs] clear_extent_bit+0x15/0x20 [btrfs] btrfs_invalidatepage+0x2b7/0x3c0 [btrfs] truncate_cleanup_page+0x47/0xe0 truncate_inode_pages_range+0x238/0x840 truncate_pagecache+0x44/0x60 btrfs_setattr+0x202/0x5e0 [btrfs] notify_change+0x33b/0x490 do_truncate+0x76/0xd0 path_openat+0x687/0xa10 do_filp_open+0x91/0x100 do_sys_openat2+0x215/0x2d0 do_sys_open+0x44/0x80 do_syscall_64+0x52/0xb0 entry_SYSCALL_64_after_hwframe+0x44/0xa9 -> #1 (&tree->lock#2){+.+.}-{2:2}: _raw_spin_lock+0x25/0x30 find_first_extent_bit+0x32/0x150 [btrfs] write_pinned_extent_entries.isra.0+0xc5/0x100 [btrfs] __btrfs_write_out_cache+0x172/0x480 [btrfs] btrfs_write_out_cache+0x7a/0xf0 [btrfs] btrfs_write_dirty_block_groups+0x286/0x3b0 [btrfs] commit_cowonly_roots+0x245/0x300 [btrfs] btrfs_commit_transaction+0x4ed/0xac0 [btrfs] close_ctree+0xf9/0x2f5 [btrfs] generic_shutdown_super+0x6c/0x100 kill_anon_super+0x14/0x30 btrfs_kill_super+0x12/0x20 [btrfs] deactivate_locked_super+0x36/0x70 cleanup_mnt+0x104/0x160 task_work_run+0x5f/0x90 __prepare_exit_to_usermode+0x1bd/0x1c0 do_syscall_64+0x5e/0xb0 entry_SYSCALL_64_after_hwframe+0x44/0xa9 -> #0 (&ctl->tree_lock){+.+.}-{2:2}: __lock_acquire+0x1240/0x2460 lock_acquire+0xab/0x360 _raw_spin_lock+0x25/0x30 btrfs_dump_free_space+0x2b/0xa0 [btrfs] btrfs_dump_space_info+0xf4/0x120 [btrfs] btrfs_reserve_extent+0x176/0x180 [btrfs] __btrfs_prealloc_file_range+0x145/0x550 [btrfs] cache_save_setup+0x28d/0x3b0 [btrfs] btrfs_start_dirty_block_groups+0x1fc/0x4f0 [btrfs] btrfs_commit_transaction+0xcc/0xac0 [btrfs] btrfs_alloc_data_chunk_ondemand+0x162/0x4c0 [btrfs] btrfs_check_data_free_space+0x4c/0xa0 [btrfs] btrfs_buffered_write.isra.0+0x19b/0x740 [btrfs] btrfs_file_write_iter+0x3cf/0x610 [btrfs] new_sync_write+0x11e/0x1b0 vfs_write+0x1c9/0x200 ksys_write+0x68/0xe0 do_syscall_64+0x52/0xb0 entry_SYSCALL_64_after_hwframe+0x44/0xa9 other info that might help us debug this: Chain exists of: &ctl->tree_lock --> &space_info->lock --> &cache->lock Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&cache->lock); lock(&space_info->lock); lock(&cache->lock); lock(&ctl->tree_lock); *** DEADLOCK *** 6 locks held by dd/563090: #0: ffff9e7e21d18448 (sb_writers#14){.+.+}-{0:0}, at: vfs_write+0x195/0x200 #1: ffff9e7dd0410ed8 (&sb->s_type->i_mutex_key#19){++++}-{3:3}, at: btrfs_file_write_iter+0x86/0x610 [btrfs] #2: ffff9e7e21d18638 (sb_internal#2){.+.+}-{0:0}, at: start_transaction+0x40b/0x5b0 [btrfs] #3: ffff9e7e1f05d688 (&cur_trans->cache_write_mutex){+.+.}-{3:3}, at: btrfs_start_dirty_block_groups+0x158/0x4f0 [btrfs] #4: ffff9e7e2284ddb8 (&space_info->groups_sem){++++}-{3:3}, at: btrfs_dump_space_info+0x69/0x120 [btrfs] #5: ffff9e7e2284d428 (&cache->lock){+.+.}-{2:2}, at: btrfs_dump_space_info+0xaa/0x120 [btrfs] stack backtrace: CPU: 3 PID: 563090 Comm: dd Tainted: G OE 5.8.0-rc5+ #20 Hardware name: To Be Filled By O.E.M. To Be Filled By O.E.M./890FX Deluxe5, BIOS P1.40 05/03/2011 Call Trace: dump_stack+0x96/0xd0 check_noncircular+0x162/0x180 __lock_acquire+0x1240/0x2460 ? wake_up_klogd.part.0+0x30/0x40 lock_acquire+0xab/0x360 ? btrfs_dump_free_space+0x2b/0xa0 [btrfs] _raw_spin_lock+0x25/0x30 ? btrfs_dump_free_space+0x2b/0xa0 [btrfs] btrfs_dump_free_space+0x2b/0xa0 [btrfs] btrfs_dump_space_info+0xf4/0x120 [btrfs] btrfs_reserve_extent+0x176/0x180 [btrfs] __btrfs_prealloc_file_range+0x145/0x550 [btrfs] ? btrfs_qgroup_reserve_data+0x1d/0x60 [btrfs] cache_save_setup+0x28d/0x3b0 [btrfs] btrfs_start_dirty_block_groups+0x1fc/0x4f0 [btrfs] btrfs_commit_transaction+0xcc/0xac0 [btrfs] ? start_transaction+0xe0/0x5b0 [btrfs] btrfs_alloc_data_chunk_ondemand+0x162/0x4c0 [btrfs] btrfs_check_data_free_space+0x4c/0xa0 [btrfs] btrfs_buffered_write.isra.0+0x19b/0x740 [btrfs] ? ktime_get_coarse_real_ts64+0xa8/0xd0 ? trace_hardirqs_on+0x1c/0xe0 btrfs_file_write_iter+0x3cf/0x610 [btrfs] new_sync_write+0x11e/0x1b0 vfs_write+0x1c9/0x200 ksys_write+0x68/0xe0 do_syscall_64+0x52/0xb0 entry_SYSCALL_64_after_hwframe+0x44/0xa9 This is because we're holding the block_group->lock while trying to dump the free space cache. However we don't need this lock, we just need it to read the values for the printk, so move the free space cache dumping outside of the block group lock. Signed-off-by: Josef Bacik <josef@toxicpanda.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Sasha Levin <sashal@kernel.org>

commit 01d01ca upstream. We are currently getting this lockdep splat in btrfs/161: ====================================================== WARNING: possible circular locking dependency detected 5.8.0-rc5+ #20 Tainted: G E ------------------------------------------------------ mount/678048 is trying to acquire lock: ffff9b769f15b6e0 (&fs_devs->device_list_mutex){+.+.}-{3:3}, at: clone_fs_devices+0x4d/0x170 [btrfs] but task is already holding lock: ffff9b76abdb08d0 (&fs_info->chunk_mutex){+.+.}-{3:3}, at: btrfs_read_chunk_tree+0x6a/0x800 [btrfs] which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #1 (&fs_info->chunk_mutex){+.+.}-{3:3}: __mutex_lock+0x8b/0x8f0 btrfs_init_new_device+0x2d2/0x1240 [btrfs] btrfs_ioctl+0x1de/0x2d20 [btrfs] ksys_ioctl+0x87/0xc0 __x64_sys_ioctl+0x16/0x20 do_syscall_64+0x52/0xb0 entry_SYSCALL_64_after_hwframe+0x44/0xa9 -> #0 (&fs_devs->device_list_mutex){+.+.}-{3:3}: __lock_acquire+0x1240/0x2460 lock_acquire+0xab/0x360 __mutex_lock+0x8b/0x8f0 clone_fs_devices+0x4d/0x170 [btrfs] btrfs_read_chunk_tree+0x330/0x800 [btrfs] open_ctree+0xb7c/0x18ce [btrfs] btrfs_mount_root.cold+0x13/0xfa [btrfs] legacy_get_tree+0x30/0x50 vfs_get_tree+0x28/0xc0 fc_mount+0xe/0x40 vfs_kern_mount.part.0+0x71/0x90 btrfs_mount+0x13b/0x3e0 [btrfs] legacy_get_tree+0x30/0x50 vfs_get_tree+0x28/0xc0 do_mount+0x7de/0xb30 __x64_sys_mount+0x8e/0xd0 do_syscall_64+0x52/0xb0 entry_SYSCALL_64_after_hwframe+0x44/0xa9 other info that might help us debug this: Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&fs_info->chunk_mutex); lock(&fs_devs->device_list_mutex); lock(&fs_info->chunk_mutex); lock(&fs_devs->device_list_mutex); *** DEADLOCK *** 3 locks held by mount/678048: #0: ffff9b75ff5fb0e0 (&type->s_umount_key#63/1){+.+.}-{3:3}, at: alloc_super+0xb5/0x380 #1: ffffffffc0c2fbc8 (uuid_mutex){+.+.}-{3:3}, at: btrfs_read_chunk_tree+0x54/0x800 [btrfs] #2: ffff9b76abdb08d0 (&fs_info->chunk_mutex){+.+.}-{3:3}, at: btrfs_read_chunk_tree+0x6a/0x800 [btrfs] stack backtrace: CPU: 2 PID: 678048 Comm: mount Tainted: G E 5.8.0-rc5+ #20 Hardware name: To Be Filled By O.E.M. To Be Filled By O.E.M./890FX Deluxe5, BIOS P1.40 05/03/2011 Call Trace: dump_stack+0x96/0xd0 check_noncircular+0x162/0x180 __lock_acquire+0x1240/0x2460 ? asm_sysvec_apic_timer_interrupt+0x12/0x20 lock_acquire+0xab/0x360 ? clone_fs_devices+0x4d/0x170 [btrfs] __mutex_lock+0x8b/0x8f0 ? clone_fs_devices+0x4d/0x170 [btrfs] ? rcu_read_lock_sched_held+0x52/0x60 ? cpumask_next+0x16/0x20 ? module_assert_mutex_or_preempt+0x14/0x40 ? __module_address+0x28/0xf0 ? clone_fs_devices+0x4d/0x170 [btrfs] ? static_obj+0x4f/0x60 ? lockdep_init_map_waits+0x43/0x200 ? clone_fs_devices+0x4d/0x170 [btrfs] clone_fs_devices+0x4d/0x170 [btrfs] btrfs_read_chunk_tree+0x330/0x800 [btrfs] open_ctree+0xb7c/0x18ce [btrfs] ? super_setup_bdi_name+0x79/0xd0 btrfs_mount_root.cold+0x13/0xfa [btrfs] ? vfs_parse_fs_string+0x84/0xb0 ? rcu_read_lock_sched_held+0x52/0x60 ? kfree+0x2b5/0x310 legacy_get_tree+0x30/0x50 vfs_get_tree+0x28/0xc0 fc_mount+0xe/0x40 vfs_kern_mount.part.0+0x71/0x90 btrfs_mount+0x13b/0x3e0 [btrfs] ? cred_has_capability+0x7c/0x120 ? rcu_read_lock_sched_held+0x52/0x60 ? legacy_get_tree+0x30/0x50 legacy_get_tree+0x30/0x50 vfs_get_tree+0x28/0xc0 do_mount+0x7de/0xb30 ? memdup_user+0x4e/0x90 __x64_sys_mount+0x8e/0xd0 do_syscall_64+0x52/0xb0 entry_SYSCALL_64_after_hwframe+0x44/0xa9 This is because btrfs_read_chunk_tree() can come upon DEV_EXTENT's and then read the device, which takes the device_list_mutex. The device_list_mutex needs to be taken before the chunk_mutex, so this is a problem. We only really need the chunk mutex around adding the chunk, so move the mutex around read_one_chunk. An argument could be made that we don't even need the chunk_mutex here as it's during mount, and we are protected by various other locks. However we already have special rules for ->device_list_mutex, and I'd rather not have another special case for ->chunk_mutex. CC: stable@vger.kernel.org # 4.19+ Reviewed-by: Anand Jain <anand.jain@oracle.com> Signed-off-by: Josef Bacik <josef@toxicpanda.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

[ Upstream commit 00d6a28 ] Commit a5a9230 (fbdev: fbcon: Properly revert changes when vc_resize() failed) started restoring old font data upon failure (of vc_resize()). But it performs so only for user fonts. It means that the "system"/internal fonts are not restored at all. So in result, the very first call to fbcon_do_set_font() performs no restore at all upon failing vc_resize(). This can be reproduced by Syzkaller to crash the system on the next invocation of font_get(). It's rather hard to hit the allocation failure in vc_resize() on the first font_set(), but not impossible. Esp. if fault injection is used to aid the execution/failure. It was demonstrated by Sirius: BUG: unable to handle page fault for address: fffffffffffffff8 #PF: supervisor read access in kernel mode #PF: error_code(0x0000) - not-present page PGD cb7b067 P4D cb7b067 PUD cb7d067 PMD 0 Oops: 0000 [#1] PREEMPT SMP KASAN CPU: 1 PID: 8007 Comm: poc Not tainted 6.7.0-g9d1694dc91ce #20 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.15.0-1 04/01/2014 RIP: 0010:fbcon_get_font+0x229/0x800 drivers/video/fbdev/core/fbcon.c:2286 Call Trace: <TASK> con_font_get drivers/tty/vt/vt.c:4558 [inline] con_font_op+0x1fc/0xf20 drivers/tty/vt/vt.c:4673 vt_k_ioctl drivers/tty/vt/vt_ioctl.c:474 [inline] vt_ioctl+0x632/0x2ec0 drivers/tty/vt/vt_ioctl.c:752 tty_ioctl+0x6f8/0x1570 drivers/tty/tty_io.c:2803 vfs_ioctl fs/ioctl.c:51 [inline] ... So restore the font data in any case, not only for user fonts. Note the later 'if' is now protected by 'old_userfont' and not 'old_data' as the latter is always set now. (And it is supposed to be non-NULL. Otherwise we would see the bug above again.) Signed-off-by: Jiri Slaby (SUSE) <jirislaby@kernel.org> Fixes: a5a9230 ("fbdev: fbcon: Properly revert changes when vc_resize() failed") Reported-and-tested-by: Ubisectech Sirius <bugreport@ubisectech.com> Cc: Ubisectech Sirius <bugreport@ubisectech.com> Cc: Daniel Vetter <daniel@ffwll.ch> Cc: Helge Deller <deller@gmx.de> Cc: linux-fbdev@vger.kernel.org Cc: dri-devel@lists.freedesktop.org Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch> Link: https://patchwork.freedesktop.org/patch/msgid/20240208114411.14604-1-jirislaby@kernel.org Signed-off-by: Sasha Levin <sashal@kernel.org>

commit a5b862c upstream. l2cap_le_flowctl_init() can cause both div-by-zero and an integer overflow since hdev->le_mtu may not fall in the valid range. Move MTU from hci_dev to hci_conn to validate MTU and stop the connection process earlier if MTU is invalid. Also, add a missing validation in read_buffer_size() and make it return an error value if the validation fails. Now hci_conn_add() returns ERR_PTR() as it can fail due to the both a kzalloc failure and invalid MTU value. divide error: 0000 [#1] PREEMPT SMP KASAN NOPTI CPU: 0 PID: 67 Comm: kworker/u5:0 Tainted: G W 6.9.0-rc5+ #20 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.15.0-1 04/01/2014 Workqueue: hci0 hci_rx_work RIP: 0010:l2cap_le_flowctl_init+0x19e/0x3f0 net/bluetooth/l2cap_core.c:547 Code: e8 17 17 0c 00 66 41 89 9f 84 00 00 00 bf 01 00 00 00 41 b8 02 00 00 00 4c 89 fe 4c 89 e2 89 d9 e8 27 17 0c 00 44 89 f0 31 d2 <66> f7 f3 89 c3 ff c3 4d 8d b7 88 00 00 00 4c 89 f0 48 c1 e8 03 42 RSP: 0018:ffff88810bc0f858 EFLAGS: 00010246 RAX: 00000000000002a0 RBX: 0000000000000000 RCX: dffffc0000000000 RDX: 0000000000000000 RSI: ffff88810bc0f7c0 RDI: ffffc90002dcb66f RBP: ffff88810bc0f880 R08: aa69db2dda70ff01 R09: 0000ffaaaaaaaaaa R10: 0084000000ffaaaa R11: 0000000000000000 R12: ffff88810d65a084 R13: dffffc0000000000 R14: 00000000000002a0 R15: ffff88810d65a000 FS: 0000000000000000(0000) GS:ffff88811ac00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000020000100 CR3: 0000000103268003 CR4: 0000000000770ef0 PKRU: 55555554 Call Trace: <TASK> l2cap_le_connect_req net/bluetooth/l2cap_core.c:4902 [inline] l2cap_le_sig_cmd net/bluetooth/l2cap_core.c:5420 [inline] l2cap_le_sig_channel net/bluetooth/l2cap_core.c:5486 [inline] l2cap_recv_frame+0xe59d/0x11710 net/bluetooth/l2cap_core.c:6809 l2cap_recv_acldata+0x544/0x10a0 net/bluetooth/l2cap_core.c:7506 hci_acldata_packet net/bluetooth/hci_core.c:3939 [inline] hci_rx_work+0x5e5/0xb20 net/bluetooth/hci_core.c:4176 process_one_work kernel/workqueue.c:3254 [inline] process_scheduled_works+0x90f/0x1530 kernel/workqueue.c:3335 worker_thread+0x926/0xe70 kernel/workqueue.c:3416 kthread+0x2e3/0x380 kernel/kthread.c:388 ret_from_fork+0x5c/0x90 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 </TASK> Modules linked in: ---[ end trace 0000000000000000 ]--- Fixes: 6ed58ec ("Bluetooth: Use LE buffers for LE traffic") Suggested-by: Luiz Augusto von Dentz <luiz.dentz@gmail.com> Signed-off-by: Sungwoo Kim <iam@sung-woo.kim> Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

[ Upstream commit 769e6a1 ] ui_browser__show() is capturing the input title that is stack allocated memory in hist_browser__run(). Avoid a use after return by strdup-ing the string. Committer notes: Further explanation from Ian Rogers: My command line using tui is: $ sudo bash -c 'rm /tmp/asan.log*; export ASAN_OPTIONS="log_path=/tmp/asan.log"; /tmp/perf/perf mem record -a sleep 1; /tmp/perf/perf mem report' I then go to the perf annotate view and quit. This triggers the asan error (from the log file): ``` ==1254591==ERROR: AddressSanitizer: stack-use-after-return on address 0x7f2813331920 at pc 0x7f28180 65991 bp 0x7fff0a21c750 sp 0x7fff0a21bf10 READ of size 80 at 0x7f2813331920 thread T0 #0 0x7f2818065990 in __interceptor_strlen ../../../../src/libsanitizer/sanitizer_common/sanitizer_common_interceptors.inc:461 #1 0x7f2817698251 in SLsmg_write_wrapped_string (/lib/x86_64-linux-gnu/libslang.so.2+0x98251) #2 0x7f28176984b9 in SLsmg_write_nstring (/lib/x86_64-linux-gnu/libslang.so.2+0x984b9) #3 0x55c94045b365 in ui_browser__write_nstring ui/browser.c:60 #4 0x55c94045c558 in __ui_browser__show_title ui/browser.c:266 #5 0x55c94045c776 in ui_browser__show ui/browser.c:288 #6 0x55c94045c06d in ui_browser__handle_resize ui/browser.c:206 #7 0x55c94047979b in do_annotate ui/browsers/hists.c:2458 #8 0x55c94047fb17 in evsel__hists_browse ui/browsers/hists.c:3412 #9 0x55c940480a0c in perf_evsel_menu__run ui/browsers/hists.c:3527 #10 0x55c940481108 in __evlist__tui_browse_hists ui/browsers/hists.c:3613 #11 0x55c9404813f7 in evlist__tui_browse_hists ui/browsers/hists.c:3661 #12 0x55c93ffa253f in report__browse_hists tools/perf/builtin-report.c:671 #13 0x55c93ffa58ca in __cmd_report tools/perf/builtin-report.c:1141 #14 0x55c93ffaf159 in cmd_report tools/perf/builtin-report.c:1805 #15 0x55c94000c05c in report_events tools/perf/builtin-mem.c:374 #16 0x55c94000d96d in cmd_mem tools/perf/builtin-mem.c:516 #17 0x55c9400e44ee in run_builtin tools/perf/perf.c:350 #18 0x55c9400e4a5a in handle_internal_command tools/perf/perf.c:403 #19 0x55c9400e4e22 in run_argv tools/perf/perf.c:447 #20 0x55c9400e53ad in main tools/perf/perf.c:561 #21 0x7f28170456c9 in __libc_start_call_main ../sysdeps/nptl/libc_start_call_main.h:58 #22 0x7f2817045784 in __libc_start_main_impl ../csu/libc-start.c:360 #23 0x55c93ff544c0 in _start (/tmp/perf/perf+0x19a4c0) (BuildId: 84899b0e8c7d3a3eaa67b2eb35e3d8b2f8cd4c93) Address 0x7f2813331920 is located in stack of thread T0 at offset 32 in frame #0 0x55c94046e85e in hist_browser__run ui/browsers/hists.c:746 This frame has 1 object(s): [32, 192) 'title' (line 747) <== Memory access at offset 32 is inside this variable HINT: this may be a false positive if your program uses some custom stack unwind mechanism, swapcontext or vfork ``` hist_browser__run isn't on the stack so the asan error looks legit. There's no clean init/exit on struct ui_browser so I may be trading a use-after-return for a memory leak, but that seems look a good trade anyway. Fixes: 05e8b08 ("perf ui browser: Stop using 'self'") Signed-off-by: Ian Rogers <irogers@google.com> Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Andi Kleen <ak@linux.intel.com> Cc: Athira Rajeev <atrajeev@linux.vnet.ibm.com> Cc: Ben Gainey <ben.gainey@arm.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: James Clark <james.clark@arm.com> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Kajol Jain <kjain@linux.ibm.com> Cc: Kan Liang <kan.liang@linux.intel.com> Cc: K Prateek Nayak <kprateek.nayak@amd.com> Cc: Li Dong <lidong@vivo.com> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Oliver Upton <oliver.upton@linux.dev> Cc: Paran Lee <p4ranlee@gmail.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Ravi Bangoria <ravi.bangoria@amd.com> Cc: Sun Haiyong <sunhaiyong@loongson.cn> Cc: Tim Chen <tim.c.chen@linux.intel.com> Cc: Yanteng Si <siyanteng@loongson.cn> Cc: Yicong Yang <yangyicong@hisilicon.com> Link: https://lore.kernel.org/r/20240507183545.1236093-2-irogers@google.com Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com> Signed-off-by: Sasha Levin <sashal@kernel.org>

[ Upstream commit a5b862c ] l2cap_le_flowctl_init() can cause both div-by-zero and an integer overflow since hdev->le_mtu may not fall in the valid range. Move MTU from hci_dev to hci_conn to validate MTU and stop the connection process earlier if MTU is invalid. Also, add a missing validation in read_buffer_size() and make it return an error value if the validation fails. Now hci_conn_add() returns ERR_PTR() as it can fail due to the both a kzalloc failure and invalid MTU value. divide error: 0000 [#1] PREEMPT SMP KASAN NOPTI CPU: 0 PID: 67 Comm: kworker/u5:0 Tainted: G W 6.9.0-rc5+ #20 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.15.0-1 04/01/2014 Workqueue: hci0 hci_rx_work RIP: 0010:l2cap_le_flowctl_init+0x19e/0x3f0 net/bluetooth/l2cap_core.c:547 Code: e8 17 17 0c 00 66 41 89 9f 84 00 00 00 bf 01 00 00 00 41 b8 02 00 00 00 4c 89 fe 4c 89 e2 89 d9 e8 27 17 0c 00 44 89 f0 31 d2 <66> f7 f3 89 c3 ff c3 4d 8d b7 88 00 00 00 4c 89 f0 48 c1 e8 03 42 RSP: 0018:ffff88810bc0f858 EFLAGS: 00010246 RAX: 00000000000002a0 RBX: 0000000000000000 RCX: dffffc0000000000 RDX: 0000000000000000 RSI: ffff88810bc0f7c0 RDI: ffffc90002dcb66f RBP: ffff88810bc0f880 R08: aa69db2dda70ff01 R09: 0000ffaaaaaaaaaa R10: 0084000000ffaaaa R11: 0000000000000000 R12: ffff88810d65a084 R13: dffffc0000000000 R14: 00000000000002a0 R15: ffff88810d65a000 FS: 0000000000000000(0000) GS:ffff88811ac00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000020000100 CR3: 0000000103268003 CR4: 0000000000770ef0 PKRU: 55555554 Call Trace: <TASK> l2cap_le_connect_req net/bluetooth/l2cap_core.c:4902 [inline] l2cap_le_sig_cmd net/bluetooth/l2cap_core.c:5420 [inline] l2cap_le_sig_channel net/bluetooth/l2cap_core.c:5486 [inline] l2cap_recv_frame+0xe59d/0x11710 net/bluetooth/l2cap_core.c:6809 l2cap_recv_acldata+0x544/0x10a0 net/bluetooth/l2cap_core.c:7506 hci_acldata_packet net/bluetooth/hci_core.c:3939 [inline] hci_rx_work+0x5e5/0xb20 net/bluetooth/hci_core.c:4176 process_one_work kernel/workqueue.c:3254 [inline] process_scheduled_works+0x90f/0x1530 kernel/workqueue.c:3335 worker_thread+0x926/0xe70 kernel/workqueue.c:3416 kthread+0x2e3/0x380 kernel/kthread.c:388 ret_from_fork+0x5c/0x90 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 </TASK> Modules linked in: ---[ end trace 0000000000000000 ]--- Fixes: 6ed58ec ("Bluetooth: Use LE buffers for LE traffic") Suggested-by: Luiz Augusto von Dentz <luiz.dentz@gmail.com> Signed-off-by: Sungwoo Kim <iam@sung-woo.kim> Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com> Signed-off-by: Sasha Levin <sashal@kernel.org>

commit be346c1 upstream. The code in ocfs2_dio_end_io_write() estimates number of necessary transaction credits using ocfs2_calc_extend_credits(). This however does not take into account that the IO could be arbitrarily large and can contain arbitrary number of extents. Extent tree manipulations do often extend the current transaction but not in all of the cases. For example if we have only single block extents in the tree, ocfs2_mark_extent_written() will end up calling ocfs2_replace_extent_rec() all the time and we will never extend the current transaction and eventually exhaust all the transaction credits if the IO contains many single block extents. Once that happens a WARN_ON(jbd2_handle_buffer_credits(handle) <= 0) is triggered in jbd2_journal_dirty_metadata() and subsequently OCFS2 aborts in response to this error. This was actually triggered by one of our customers on a heavily fragmented OCFS2 filesystem. To fix the issue make sure the transaction always has enough credits for one extent insert before each call of ocfs2_mark_extent_written(). Heming Zhao said: ------ PANIC: "Kernel panic - not syncing: OCFS2: (device dm-1): panic forced after error" PID: xxx TASK: xxxx CPU: 5 COMMAND: "SubmitThread-CA" #0 machine_kexec at ffffffff8c069932 #1 __crash_kexec at ffffffff8c1338fa #2 panic at ffffffff8c1d69b9 #3 ocfs2_handle_error at ffffffffc0c86c0c [ocfs2] #4 __ocfs2_abort at ffffffffc0c88387 [ocfs2] #5 ocfs2_journal_dirty at ffffffffc0c51e98 [ocfs2] #6 ocfs2_split_extent at ffffffffc0c27ea3 [ocfs2] #7 ocfs2_change_extent_flag at ffffffffc0c28053 [ocfs2] #8 ocfs2_mark_extent_written at ffffffffc0c28347 [ocfs2] #9 ocfs2_dio_end_io_write at ffffffffc0c2bef9 [ocfs2] #10 ocfs2_dio_end_io at ffffffffc0c2c0f5 [ocfs2] #11 dio_complete at ffffffff8c2b9fa7 #12 do_blockdev_direct_IO at ffffffff8c2bc09f #13 ocfs2_direct_IO at ffffffffc0c2b653 [ocfs2] #14 generic_file_direct_write at ffffffff8c1dcf14 #15 __generic_file_write_iter at ffffffff8c1dd07b #16 ocfs2_file_write_iter at ffffffffc0c49f1f [ocfs2] #17 aio_write at ffffffff8c2cc72e #18 kmem_cache_alloc at ffffffff8c248dde #19 do_io_submit at ffffffff8c2ccada #20 do_syscall_64 at ffffffff8c004984 #21 entry_SYSCALL_64_after_hwframe at ffffffff8c8000ba Link: https://lkml.kernel.org/r/20240617095543.6971-1-jack@suse.cz Link: https://lkml.kernel.org/r/20240614145243.8837-1-jack@suse.cz Fixes: c15471f ("ocfs2: fix sparse file & data ordering issue in direct io") Signed-off-by: Jan Kara <jack@suse.cz> Reviewed-by: Joseph Qi <joseph.qi@linux.alibaba.com> Reviewed-by: Heming Zhao <heming.zhao@suse.com> Cc: Mark Fasheh <mark@fasheh.com> Cc: Joel Becker <jlbec@evilplan.org> Cc: Junxiao Bi <junxiao.bi@oracle.com> Cc: Changwei Ge <gechangwei@live.cn> Cc: Gang He <ghe@suse.com> Cc: Jun Piao <piaojun@huawei.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

commit bab4923 upstream. In the TRACE_EVENT(qdisc_reset) NULL dereference occurred from qdisc->dev_queue->dev <NULL> ->name This situation simulated from bunch of veths and Bluetooth disconnection and reconnection. During qdisc initialization, qdisc was being set to noop_queue. In veth_init_queue, the initial tx_num was reduced back to one, causing the qdisc reset to be called with noop, which led to the kernel panic. I've attached the GitHub gist link that C converted syz-execprogram source code and 3 log of reproduced vmcore-dmesg. https://gist.github.com/yskelg/cc64562873ce249cdd0d5a358b77d740 Yeoreum and I use two fuzzing tool simultaneously. One process with syz-executor : https://github.com/google/syzkaller $ ./syz-execprog -executor=./syz-executor -repeat=1 -sandbox=setuid \ -enable=none -collide=false log1 The other process with perf fuzzer: https://github.com/deater/perf_event_tests/tree/master/fuzzer $ perf_event_tests/fuzzer/perf_fuzzer I think this will happen on the kernel version. Linux kernel version +v6.7.10, +v6.8, +v6.9 and it could happen in v6.10. This occurred from 51270d5. I think this patch is absolutely necessary. Previously, It was showing not intended string value of name. I've reproduced 3 time from my fedora 40 Debug Kernel with any other module or patched. version: 6.10.0-0.rc2.20240608gitdc772f8237f9.29.fc41.aarch64+debug [ 5287.164555] veth0_vlan: left promiscuous mode [ 5287.164929] veth1_macvtap: left promiscuous mode [ 5287.164950] veth0_macvtap: left promiscuous mode [ 5287.164983] veth1_vlan: left promiscuous mode [ 5287.165008] veth0_vlan: left promiscuous mode [ 5287.165450] veth1_macvtap: left promiscuous mode [ 5287.165472] veth0_macvtap: left promiscuous mode [ 5287.165502] veth1_vlan: left promiscuous mode … [ 5297.598240] bridge0: port 2(bridge_slave_1) entered blocking state [ 5297.598262] bridge0: port 2(bridge_slave_1) entered forwarding state [ 5297.598296] bridge0: port 1(bridge_slave_0) entered blocking state [ 5297.598313] bridge0: port 1(bridge_slave_0) entered forwarding state [ 5297.616090] 8021q: adding VLAN 0 to HW filter on device bond0 [ 5297.620405] bridge0: port 1(bridge_slave_0) entered disabled state [ 5297.620730] bridge0: port 2(bridge_slave_1) entered disabled state [ 5297.627247] 8021q: adding VLAN 0 to HW filter on device team0 [ 5297.629636] bridge0: port 1(bridge_slave_0) entered blocking state … [ 5298.002798] bridge_slave_0: left promiscuous mode [ 5298.002869] bridge0: port 1(bridge_slave_0) entered disabled state [ 5298.309444] bond0 (unregistering): (slave bond_slave_0): Releasing backup interface [ 5298.315206] bond0 (unregistering): (slave bond_slave_1): Releasing backup interface [ 5298.320207] bond0 (unregistering): Released all slaves [ 5298.354296] hsr_slave_0: left promiscuous mode [ 5298.360750] hsr_slave_1: left promiscuous mode [ 5298.374889] veth1_macvtap: left promiscuous mode [ 5298.374931] veth0_macvtap: left promiscuous mode [ 5298.374988] veth1_vlan: left promiscuous mode [ 5298.375024] veth0_vlan: left promiscuous mode [ 5299.109741] team0 (unregistering): Port device team_slave_1 removed [ 5299.185870] team0 (unregistering): Port device team_slave_0 removed … [ 5300.155443] Bluetooth: hci3: unexpected cc 0x0c03 length: 249 > 1 [ 5300.155724] Bluetooth: hci3: unexpected cc 0x1003 length: 249 > 9 [ 5300.155988] Bluetooth: hci3: unexpected cc 0x1001 length: 249 > 9 …. [ 5301.075531] team0: Port device team_slave_1 added [ 5301.085515] bridge0: port 1(bridge_slave_0) entered blocking state [ 5301.085531] bridge0: port 1(bridge_slave_0) entered disabled state [ 5301.085588] bridge_slave_0: entered allmulticast mode [ 5301.085800] bridge_slave_0: entered promiscuous mode [ 5301.095617] bridge0: port 1(bridge_slave_0) entered blocking state [ 5301.095633] bridge0: port 1(bridge_slave_0) entered disabled state … [ 5301.149734] bond0: (slave bond_slave_0): Enslaving as an active interface with an up link [ 5301.173234] bond0: (slave bond_slave_0): Enslaving as an active interface with an up link [ 5301.180517] bond0: (slave bond_slave_1): Enslaving as an active interface with an up link [ 5301.193481] hsr_slave_0: entered promiscuous mode [ 5301.204425] hsr_slave_1: entered promiscuous mode [ 5301.210172] debugfs: Directory 'hsr0' with parent 'hsr' already present! [ 5301.210185] Cannot create hsr debugfs directory [ 5301.224061] bond0: (slave bond_slave_1): Enslaving as an active interface with an up link [ 5301.246901] bond0: (slave bond_slave_0): Enslaving as an active interface with an up link [ 5301.255934] team0: Port device team_slave_0 added [ 5301.256480] team0: Port device team_slave_1 added [ 5301.256948] team0: Port device team_slave_0 added … [ 5301.435928] hsr_slave_0: entered promiscuous mode [ 5301.446029] hsr_slave_1: entered promiscuous mode [ 5301.455872] debugfs: Directory 'hsr0' with parent 'hsr' already present! [ 5301.455884] Cannot create hsr debugfs directory [ 5301.502664] hsr_slave_0: entered promiscuous mode [ 5301.513675] hsr_slave_1: entered promiscuous mode [ 5301.526155] debugfs: Directory 'hsr0' with parent 'hsr' already present! [ 5301.526164] Cannot create hsr debugfs directory [ 5301.563662] hsr_slave_0: entered promiscuous mode [ 5301.576129] hsr_slave_1: entered promiscuous mode [ 5301.580259] debugfs: Directory 'hsr0' with parent 'hsr' already present! [ 5301.580270] Cannot create hsr debugfs directory [ 5301.590269] 8021q: adding VLAN 0 to HW filter on device bond0 [ 5301.595872] KASAN: null-ptr-deref in range [0x0000000000000130-0x0000000000000137] [ 5301.595877] Mem abort info: [ 5301.595881] ESR = 0x0000000096000006 [ 5301.595885] EC = 0x25: DABT (current EL), IL = 32 bits [ 5301.595889] SET = 0, FnV = 0 [ 5301.595893] EA = 0, S1PTW = 0 [ 5301.595896] FSC = 0x06: level 2 translation fault [ 5301.595900] Data abort info: [ 5301.595903] ISV = 0, ISS = 0x00000006, ISS2 = 0x00000000 [ 5301.595907] CM = 0, WnR = 0, TnD = 0, TagAccess = 0 [ 5301.595911] GCS = 0, Overlay = 0, DirtyBit = 0, Xs = 0 [ 5301.595915] [dfff800000000026] address between user and kernel address ranges [ 5301.595971] Internal error: Oops: 0000000096000006 [#1] SMP … [ 5301.596076] CPU: 2 PID: 102769 Comm: syz-executor.3 Kdump: loaded Tainted: G W ------- --- 6.10.0-0.rc2.20240608gitdc772f8237f9.29.fc41.aarch64+debug #1 [ 5301.596080] Hardware name: VMware, Inc. VMware20,1/VBSA, BIOS VMW201.00V.21805430.BA64.2305221830 05/22/2023 [ 5301.596082] pstate: 01400005 (nzcv daif +PAN -UAO -TCO +DIT -SSBS BTYPE=--) [ 5301.596085] pc : strnlen+0x40/0x88 [ 5301.596114] lr : trace_event_get_offsets_qdisc_reset+0x6c/0x2b0 [ 5301.596124] sp : ffff8000beef6b40 [ 5301.596126] x29: ffff8000beef6b40 x28: dfff800000000000 x27: 0000000000000001 [ 5301.596131] x26: 6de1800082c62bd0 x25: 1ffff000110aa9e0 x24: ffff800088554f00 [ 5301.596136] x23: ffff800088554ec0 x22: 0000000000000130 x21: 0000000000000140 [ 5301.596140] x20: dfff800000000000 x19: ffff8000beef6c60 x18: ffff7000115106d8 [ 5301.596143] x17: ffff800121bad000 x16: ffff800080020000 x15: 0000000000000006 [ 5301.596147] x14: 0000000000000002 x13: ffff0001f3ed8d14 x12: ffff700017ddeda5 [ 5301.596151] x11: 1ffff00017ddeda4 x10: ffff700017ddeda4 x9 : ffff800082cc5eec [ 5301.596155] x8 : 0000000000000004 x7 : 00000000f1f1f1f1 x6 : 00000000f2f2f200 [ 5301.596158] x5 : 00000000f3f3f3f3 x4 : ffff700017dded80 x3 : 00000000f204f1f1 [ 5301.596162] x2 : 0000000000000026 x1 : 0000000000000000 x0 : 0000000000000130 [ 5301.596166] Call trace: [ 5301.596175] strnlen+0x40/0x88 [ 5301.596179] trace_event_get_offsets_qdisc_reset+0x6c/0x2b0 [ 5301.596182] perf_trace_qdisc_reset+0xb0/0x538 [ 5301.596184] __traceiter_qdisc_reset+0x68/0xc0 [ 5301.596188] qdisc_reset+0x43c/0x5e8 [ 5301.596190] netif_set_real_num_tx_queues+0x288/0x770 [ 5301.596194] veth_init_queues+0xfc/0x130 [veth] [ 5301.596198] veth_newlink+0x45c/0x850 [veth] [ 5301.596202] rtnl_newlink_create+0x2c8/0x798 [ 5301.596205] __rtnl_newlink+0x92c/0xb60 [ 5301.596208] rtnl_newlink+0xd8/0x130 [ 5301.596211] rtnetlink_rcv_msg+0x2e0/0x890 [ 5301.596214] netlink_rcv_skb+0x1c4/0x380 [ 5301.596225] rtnetlink_rcv+0x20/0x38 [ 5301.596227] netlink_unicast+0x3c8/0x640 [ 5301.596231] netlink_sendmsg+0x658/0xa60 [ 5301.596234] __sock_sendmsg+0xd0/0x180 [ 5301.596243] __sys_sendto+0x1c0/0x280 [ 5301.596246] __arm64_sys_sendto+0xc8/0x150 [ 5301.596249] invoke_syscall+0xdc/0x268 [ 5301.596256] el0_svc_common.constprop.0+0x16c/0x240 [ 5301.596259] do_el0_svc+0x48/0x68 [ 5301.596261] el0_svc+0x50/0x188 [ 5301.596265] el0t_64_sync_handler+0x120/0x130 [ 5301.596268] el0t_64_sync+0x194/0x198 [ 5301.596272] Code: eb15001f 54000120 d343fc02 12000801 (38f46842) [ 5301.596285] SMP: stopping secondary CPUs [ 5301.597053] Starting crashdump kernel... [ 5301.597057] Bye! After applying our patch, I didn't find any kernel panic errors. We've found a simple reproducer # echo 1 > /sys/kernel/debug/tracing/events/qdisc/qdisc_reset/enable # ip link add veth0 type veth peer name veth1 Error: Unknown device type. However, without our patch applied, I tested upstream 6.10.0-rc3 kernel using the qdisc_reset event and the ip command on my qemu virtual machine. This 2 commands makes always kernel panic. Linux version: 6.10.0-rc3 [ 0.000000] Linux version 6.10.0-rc3-00164-g44ef20baed8e-dirty (paran@fedora) (gcc (GCC) 14.1.1 20240522 (Red Hat 14.1.1-4), GNU ld version 2.41-34.fc40) #20 SMP PREEMPT Sat Jun 15 16:51:25 KST 2024 Kernel panic message: [ 615.236484] Internal error: Oops: 0000000096000005 [#1] PREEMPT SMP [ 615.237250] Dumping ftrace buffer: [ 615.237679] (ftrace buffer empty) [ 615.238097] Modules linked in: veth crct10dif_ce virtio_gpu virtio_dma_buf drm_shmem_helper drm_kms_helper zynqmp_fpga xilinx_can xilinx_spi xilinx_selectmap xilinx_core xilinx_pr_decoupler versal_fpga uvcvideo uvc videobuf2_vmalloc videobuf2_memops videobuf2_v4l2 videodev videobuf2_common mc usbnet deflate zstd ubifs ubi rcar_canfd rcar_can omap_mailbox ntb_msi_test ntb_hw_epf lattice_sysconfig_spi lattice_sysconfig ice40_spi gpio_xilinx dwmac_altr_socfpga mdio_regmap stmmac_platform stmmac pcs_xpcs dfl_fme_region dfl_fme_mgr dfl_fme_br dfl_afu dfl fpga_region fpga_bridge can can_dev br_netfilter bridge stp llc atl1c ath11k_pci mhi ath11k_ahb ath11k qmi_helpers ath10k_sdio ath10k_pci ath10k_core ath mac80211 libarc4 cfg80211 drm fuse backlight ipv6 Jun 22 02:36:5[3 6k152.62-4sm98k4-0k]v kCePUr:n e1l :P IUDn:a b4le6 8t oC ohmma: nidpl eN oketr nteali nptaedg i6n.g1 0re.0q-urecs3t- 0at0 1v6i4r-tgu4a4le fa2d0dbraeeds0se-dir tyd f#f2f08 615.252376] Hardware name: linux,dummy-virt (DT) [ 615.253220] pstate: 80400005 (Nzcv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--) [ 615.254433] pc : strnlen+0x6c/0xe0 [ 615.255096] lr : trace_event_get_offsets_qdisc_reset+0x94/0x3d0 [ 615.256088] sp : ffff800080b269a0 [ 615.256615] x29: ffff800080b269a0 x28: ffffc070f3f98500 x27: 0000000000000001 [ 615.257831] x26: 0000000000000010 x25: ffffc070f3f98540 x24: ffffc070f619cf60 [ 615.259020] x23: 0000000000000128 x22: 0000000000000138 x21: dfff800000000000 [ 615.260241] x20: ffffc070f631ad00 x19: 0000000000000128 x18: ffffc070f448b800 [ 615.261454] x17: 0000000000000000 x16: 0000000000000001 x15: ffffc070f4ba2a90 [ 615.262635] x14: ffff700010164d73 x13: 1ffff80e1e8d5eb3 x12: 1ffff00010164d72 [ 615.263877] x11: ffff700010164d72 x10: dfff800000000000 x9 : ffffc070e85d6184 [ 615.265047] x8 : ffffc070e4402070 x7 : 000000000000f1f1 x6 : 000000001504a6d3 [ 615.266336] x5 : ffff28ca21122140 x4 : ffffc070f5043ea8 x3 : 0000000000000000 [ 615.267528] x2 : 0000000000000025 x1 : 0000000000000000 x0 : 0000000000000000 [ 615.268747] Call trace: [ 615.269180] strnlen+0x6c/0xe0 [ 615.269767] trace_event_get_offsets_qdisc_reset+0x94/0x3d0 [ 615.270716] trace_event_raw_event_qdisc_reset+0xe8/0x4e8 [ 615.271667] __traceiter_qdisc_reset+0xa0/0x140 [ 615.272499] qdisc_reset+0x554/0x848 [ 615.273134] netif_set_real_num_tx_queues+0x360/0x9a8 [ 615.274050] veth_init_queues+0x110/0x220 [veth] [ 615.275110] veth_newlink+0x538/0xa50 [veth] [ 615.276172] __rtnl_newlink+0x11e4/0x1bc8 [ 615.276944] rtnl_newlink+0xac/0x120 [ 615.277657] rtnetlink_rcv_msg+0x4e4/0x1370 [ 615.278409] netlink_rcv_skb+0x25c/0x4f0 [ 615.279122] rtnetlink_rcv+0x48/0x70 [ 615.279769] netlink_unicast+0x5a8/0x7b8 [ 615.280462] netlink_sendmsg+0xa70/0x1190 Yeoreum and I don't know if the patch we wrote will fix the underlying cause, but we think that priority is to prevent kernel panic happening. So, we're sending this patch. Fixes: 51270d5 ("tracing/net_sched: Fix tracepoints that save qdisc_dev() as a string") Link: https://lore.kernel.org/lkml/20240229143432.273b4871@gandalf.local.home/t/ Cc: netdev@vger.kernel.org Tested-by: Yunseong Kim <yskelg@gmail.com> Signed-off-by: Yunseong Kim <yskelg@gmail.com> Signed-off-by: Yeoreum Yun <yeoreum.yun@arm.com> Link: https://lore.kernel.org/r/20240624173320.24945-4-yskelg@gmail.com Signed-off-by: Paolo Abeni <pabeni@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>