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| Kernel | Title | Rank 🛈 | Repro | Cause bisect | Fix bisect | Count | Last | Reported | Patched | Status |
|---|---|---|---|---|---|---|---|---|---|---|
| upstream | possible deadlock in kernfs_fop_write_iter kernfs | 4 | 14 | 365d | 390d | 0/29 | auto-obsoleted due to no activity on 2024/10/05 00:05 | |||
| upstream | possible deadlock in kernfs_fop_write_iter (2) kernfs | 4 | 68 | 8d06h | 286d | 0/29 | upstream: reported on 2024/10/14 06:57 | |||
| linux-5.15 | possible deadlock in kernfs_fop_write_iter (2) | 4 | 1 | 56d | 56d | 0/3 | upstream: reported on 2025/06/01 09:33 |
loop7: detected capacity change from 0 to 512
EXT4-fs (loop7): mounted filesystem without journal. Opts: bsddf,,errors=continue. Quota mode: none.
======================================================
WARNING: possible circular locking dependency detected
5.15.178-syzkaller #0 Not tainted
------------------------------------------------------
syz.7.2124/14598 is trying to acquire lock:
ffff888061ae3488 (&of->mutex){+.+.}-{3:3}, at: kernfs_fop_write_iter+0x1e7/0x4f0 fs/kernfs/file.c:287
but task is already holding lock:
ffff8880619d3c68 (&pipe->mutex/1){+.+.}-{3:3}, at: iter_file_splice_write+0x2ab/0xfa0 fs/splice.c:635
which lock already depends on the new lock.
the existing dependency chain (in reverse order) is:
-> #7 (&pipe->mutex/1){+.+.}-{3:3}:
lock_acquire+0x1db/0x4f0 kernel/locking/lockdep.c:5623
__mutex_lock_common+0x1da/0x25a0 kernel/locking/mutex.c:596
__mutex_lock kernel/locking/mutex.c:729 [inline]
mutex_lock_nested+0x17/0x20 kernel/locking/mutex.c:743
iter_file_splice_write+0x2ab/0xfa0 fs/splice.c:635
do_splice_from fs/splice.c:767 [inline]
do_splice+0xfe6/0x1790 fs/splice.c:1079
__do_splice fs/splice.c:1144 [inline]
__do_sys_splice fs/splice.c:1350 [inline]
__se_sys_splice+0x340/0x420 fs/splice.c:1332
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x66/0xd0
-> #6 (sb_writers#3){.+.+}-{0:0}:
lock_acquire+0x1db/0x4f0 kernel/locking/lockdep.c:5623
percpu_down_read include/linux/percpu-rwsem.h:51 [inline]
__sb_start_write include/linux/fs.h:1813 [inline]
sb_start_write include/linux/fs.h:1883 [inline]
file_start_write include/linux/fs.h:3044 [inline]
lo_write_bvec+0x1a3/0x740 drivers/block/loop.c:315
lo_write_simple drivers/block/loop.c:338 [inline]
do_req_filebacked drivers/block/loop.c:656 [inline]
loop_handle_cmd drivers/block/loop.c:2234 [inline]
loop_process_work+0x2309/0x2af0 drivers/block/loop.c:2274
process_one_work+0x8a1/0x10c0 kernel/workqueue.c:2310
worker_thread+0xaca/0x1280 kernel/workqueue.c:2457
kthread+0x3f6/0x4f0 kernel/kthread.c:334
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287
-> #5 ((work_completion)(&worker->work)){+.+.}-{0:0}:
lock_acquire+0x1db/0x4f0 kernel/locking/lockdep.c:5623
process_one_work+0x7f1/0x10c0 kernel/workqueue.c:2286
worker_thread+0xaca/0x1280 kernel/workqueue.c:2457
kthread+0x3f6/0x4f0 kernel/kthread.c:334
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287
-> #4 ((wq_completion)loop8){+.+.}-{0:0}:
lock_acquire+0x1db/0x4f0 kernel/locking/lockdep.c:5623
flush_workqueue+0x170/0x1610 kernel/workqueue.c:2830
drain_workqueue+0xc5/0x390 kernel/workqueue.c:2995
destroy_workqueue+0x7b/0xae0 kernel/workqueue.c:4439
__loop_clr_fd+0x241/0xbe0 drivers/block/loop.c:1383
blkdev_put_whole block/bdev.c:692 [inline]
blkdev_put+0x455/0x790 block/bdev.c:954
deactivate_locked_super+0xa0/0x110 fs/super.c:335
cleanup_mnt+0x44e/0x500 fs/namespace.c:1143
task_work_run+0x129/0x1a0 kernel/task_work.c:188
tracehook_notify_resume include/linux/tracehook.h:189 [inline]
exit_to_user_mode_loop+0x106/0x130 kernel/entry/common.c:181
exit_to_user_mode_prepare+0xb1/0x140 kernel/entry/common.c:214
__syscall_exit_to_user_mode_work kernel/entry/common.c:296 [inline]
syscall_exit_to_user_mode+0x5d/0x240 kernel/entry/common.c:307
do_syscall_64+0x47/0xb0 arch/x86/entry/common.c:86
entry_SYSCALL_64_after_hwframe+0x66/0xd0
-> #3 (&lo->lo_mutex){+.+.}-{3:3}:
lock_acquire+0x1db/0x4f0 kernel/locking/lockdep.c:5623
__mutex_lock_common+0x1da/0x25a0 kernel/locking/mutex.c:596
__mutex_lock kernel/locking/mutex.c:729 [inline]
mutex_lock_killable_nested+0x17/0x20 kernel/locking/mutex.c:758
lo_open+0x68/0x100 drivers/block/loop.c:2055
blkdev_get_whole+0x94/0x390 block/bdev.c:669
blkdev_get_by_dev+0x2bc/0xa50 block/bdev.c:824
blkdev_open+0x138/0x2d0 block/fops.c:463
do_dentry_open+0x807/0xfb0 fs/open.c:826
do_open fs/namei.c:3608 [inline]
path_openat+0x2705/0x2f20 fs/namei.c:3742
do_filp_open+0x21c/0x460 fs/namei.c:3769
do_sys_openat2+0x13b/0x4f0 fs/open.c:1253
do_sys_open fs/open.c:1269 [inline]
__do_sys_openat fs/open.c:1285 [inline]
__se_sys_openat fs/open.c:1280 [inline]
__x64_sys_openat+0x243/0x290 fs/open.c:1280
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x66/0xd0
-> #2 (&disk->open_mutex){+.+.}-{3:3}:
lock_acquire+0x1db/0x4f0 kernel/locking/lockdep.c:5623
__mutex_lock_common+0x1da/0x25a0 kernel/locking/mutex.c:596
__mutex_lock kernel/locking/mutex.c:729 [inline]
mutex_lock_nested+0x17/0x20 kernel/locking/mutex.c:743
blkdev_get_by_dev+0x14d/0xa50 block/bdev.c:817
swsusp_check+0xb1/0x2c0 kernel/power/swap.c:1526
software_resume+0xc6/0x3c0 kernel/power/hibernate.c:977
resume_store+0xe3/0x130 kernel/power/hibernate.c:1179
kernfs_fop_write_iter+0x3a2/0x4f0 fs/kernfs/file.c:296
call_write_iter include/linux/fs.h:2174 [inline]
new_sync_write fs/read_write.c:507 [inline]
vfs_write+0xacd/0xe50 fs/read_write.c:594
ksys_write+0x1a2/0x2c0 fs/read_write.c:647
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x66/0xd0
-> #1 (system_transition_mutex/1){+.+.}-{3:3}:
lock_acquire+0x1db/0x4f0 kernel/locking/lockdep.c:5623
__mutex_lock_common+0x1da/0x25a0 kernel/locking/mutex.c:596
__mutex_lock kernel/locking/mutex.c:729 [inline]
mutex_lock_nested+0x17/0x20 kernel/locking/mutex.c:743
software_resume+0x7c/0x3c0 kernel/power/hibernate.c:932
resume_store+0xe3/0x130 kernel/power/hibernate.c:1179
kernfs_fop_write_iter+0x3a2/0x4f0 fs/kernfs/file.c:296
call_write_iter include/linux/fs.h:2174 [inline]
new_sync_write fs/read_write.c:507 [inline]
vfs_write+0xacd/0xe50 fs/read_write.c:594
ksys_write+0x1a2/0x2c0 fs/read_write.c:647
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x66/0xd0
-> #0 (&of->mutex){+.+.}-{3:3}:
check_prev_add kernel/locking/lockdep.c:3053 [inline]
check_prevs_add kernel/locking/lockdep.c:3172 [inline]
validate_chain+0x1649/0x5930 kernel/locking/lockdep.c:3788
__lock_acquire+0x1295/0x1ff0 kernel/locking/lockdep.c:5012
lock_acquire+0x1db/0x4f0 kernel/locking/lockdep.c:5623
__mutex_lock_common+0x1da/0x25a0 kernel/locking/mutex.c:596
__mutex_lock kernel/locking/mutex.c:729 [inline]
mutex_lock_nested+0x17/0x20 kernel/locking/mutex.c:743
kernfs_fop_write_iter+0x1e7/0x4f0 fs/kernfs/file.c:287
do_iter_readv_writev+0x594/0x7a0
do_iter_write+0x1e6/0x760 fs/read_write.c:855
iter_file_splice_write+0x806/0xfa0 fs/splice.c:689
do_splice_from fs/splice.c:767 [inline]
do_splice+0xfe6/0x1790 fs/splice.c:1079
__do_splice fs/splice.c:1144 [inline]
__do_sys_splice fs/splice.c:1350 [inline]
__se_sys_splice+0x340/0x420 fs/splice.c:1332
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x66/0xd0
other info that might help us debug this:
Chain exists of:
&of->mutex --> sb_writers#3 --> &pipe->mutex/1
Possible unsafe locking scenario:
CPU0 CPU1
---- ----
lock(&pipe->mutex/1);
lock(sb_writers#3);
lock(&pipe->mutex/1);
lock(&of->mutex);
*** DEADLOCK ***
2 locks held by syz.7.2124/14598:
#0: ffff88807efbe460 (sb_writers#8){.+.+}-{0:0}, at: __do_splice fs/splice.c:1144 [inline]
#0: ffff88807efbe460 (sb_writers#8){.+.+}-{0:0}, at: __do_sys_splice fs/splice.c:1350 [inline]
#0: ffff88807efbe460 (sb_writers#8){.+.+}-{0:0}, at: __se_sys_splice+0x340/0x420 fs/splice.c:1332
#1: ffff8880619d3c68 (&pipe->mutex/1){+.+.}-{3:3}, at: iter_file_splice_write+0x2ab/0xfa0 fs/splice.c:635
stack backtrace:
CPU: 1 PID: 14598 Comm: syz.7.2124 Not tainted 5.15.178-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 12/27/2024
Call Trace:
<TASK>
__dump_stack lib/dump_stack.c:88 [inline]
dump_stack_lvl+0x1e3/0x2d0 lib/dump_stack.c:106
check_noncircular+0x2f8/0x3b0 kernel/locking/lockdep.c:2133
check_prev_add kernel/locking/lockdep.c:3053 [inline]
check_prevs_add kernel/locking/lockdep.c:3172 [inline]
validate_chain+0x1649/0x5930 kernel/locking/lockdep.c:3788
__lock_acquire+0x1295/0x1ff0 kernel/locking/lockdep.c:5012
lock_acquire+0x1db/0x4f0 kernel/locking/lockdep.c:5623
__mutex_lock_common+0x1da/0x25a0 kernel/locking/mutex.c:596
__mutex_lock kernel/locking/mutex.c:729 [inline]
mutex_lock_nested+0x17/0x20 kernel/locking/mutex.c:743
kernfs_fop_write_iter+0x1e7/0x4f0 fs/kernfs/file.c:287
do_iter_readv_writev+0x594/0x7a0
do_iter_write+0x1e6/0x760 fs/read_write.c:855
iter_file_splice_write+0x806/0xfa0 fs/splice.c:689
do_splice_from fs/splice.c:767 [inline]
do_splice+0xfe6/0x1790 fs/splice.c:1079
__do_splice fs/splice.c:1144 [inline]
__do_sys_splice fs/splice.c:1350 [inline]
__se_sys_splice+0x340/0x420 fs/splice.c:1332
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7f0b2e5dcde9
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f0b2c446038 EFLAGS: 00000246 ORIG_RAX: 0000000000000113
RAX: ffffffffffffffda RBX: 00007f0b2e7f5fa0 RCX: 00007f0b2e5dcde9
RDX: 0000000000000007 RSI: 0000000000000000 RDI: 0000000000000004
RBP: 00007f0b2e65e2a0 R08: 000000000000bfd1 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007f0b2e7f5fa0 R15: 00007fff8efe4d28
</TASK>
kernel profiling enabled (shift: 8)
| Time | Kernel | Commit | Syzkaller | Config | Log | Report | Syz repro | C repro | VM info | Assets (help?) | Manager | Title |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 2025/02/06 20:04 | linux-5.15.y | c16c81c81336 | 8002dd28 | .config | console log | report | info | [disk image] [vmlinux] [kernel image] | ci2-linux-5-15-kasan | possible deadlock in kernfs_fop_write_iter | ||
| 2024/11/02 01:46 | linux-5.15.y | 72244eab0dad | f00eed24 | .config | console log | report | info | [disk image] [vmlinux] [kernel image] | ci2-linux-5-15-kasan | possible deadlock in kernfs_fop_write_iter | ||
| 2024/11/02 01:45 | linux-5.15.y | 72244eab0dad | f00eed24 | .config | console log | report | info | [disk image] [vmlinux] [kernel image] | ci2-linux-5-15-kasan | possible deadlock in kernfs_fop_write_iter |