| Title | Replies (including bot) | Last reply |
|---|---|---|
| [syzbot] [jfs?] possible deadlock in jfs_commit_inode | 0 (1) | 2026/04/02 05:31 |
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| [syzbot] [jfs?] possible deadlock in jfs_commit_inode | 0 (1) | 2026/04/02 05:31 |
======================================================
WARNING: possible circular locking dependency detected
syzkaller #0 Not tainted
------------------------------------------------------
syz-executor/5841 is trying to acquire lock:
ffff88806a156358 (&jfs_ip->commit_mutex){+.+.}-{4:4}, at: jfs_commit_inode+0x1ca/0x530 fs/jfs/inode.c:108
but task is already holding lock:
ffff888035025918 (&(log)->loglock){+.+.}-{4:4}, at: jfs_umount+0x17f/0x3d0 fs/jfs/jfs_umount.c:66
which lock already depends on the new lock.
the existing dependency chain (in reverse order) is:
-> #1 (&(log)->loglock){+.+.}-{4:4}:
__mutex_lock_common kernel/locking/mutex.c:632 [inline]
__mutex_lock+0x19e/0x1420 kernel/locking/mutex.c:794
lmLog+0x78/0xa40 fs/jfs/jfs_logmgr.c:234
diLog fs/jfs/jfs_txnmgr.c:1454 [inline]
txLog fs/jfs/jfs_txnmgr.c:1406 [inline]
txCommit+0x16fb/0x5410 fs/jfs/jfs_txnmgr.c:1266
jfs_commit_inode+0x2ef/0x530 fs/jfs/inode.c:114
jfs_write_inode+0x145/0x220 fs/jfs/inode.c:138
write_inode fs/fs-writeback.c:1582 [inline]
__writeback_single_inode+0x75a/0x10e0 fs/fs-writeback.c:1825
writeback_sb_inodes+0x979/0x19d0 fs/fs-writeback.c:2054
wb_writeback+0x445/0xb00 fs/fs-writeback.c:2239
wb_do_writeback fs/fs-writeback.c:2386 [inline]
wb_workfn+0x3f8/0xf10 fs/fs-writeback.c:2426
process_one_work kernel/workqueue.c:3302 [inline]
process_scheduled_works+0xb5d/0x1860 kernel/workqueue.c:3385
worker_thread+0xa53/0xfc0 kernel/workqueue.c:3466
kthread+0x388/0x470 kernel/kthread.c:436
ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
-> #0 (&jfs_ip->commit_mutex){+.+.}-{4:4}:
check_prev_add kernel/locking/lockdep.c:3165 [inline]
check_prevs_add kernel/locking/lockdep.c:3284 [inline]
validate_chain kernel/locking/lockdep.c:3908 [inline]
__lock_acquire+0x15a5/0x2cf0 kernel/locking/lockdep.c:5237
lock_acquire+0x106/0x350 kernel/locking/lockdep.c:5868
__mutex_lock_common kernel/locking/mutex.c:632 [inline]
__mutex_lock+0x19e/0x1420 kernel/locking/mutex.c:794
jfs_commit_inode+0x1ca/0x530 fs/jfs/inode.c:108
jfs_write_inode+0x145/0x220 fs/jfs/inode.c:138
write_inode fs/fs-writeback.c:1582 [inline]
__writeback_single_inode+0x75a/0x10e0 fs/fs-writeback.c:1825
writeback_single_inode+0x4ac/0xdc0 fs/fs-writeback.c:1881
write_inode_now+0x1c2/0x290 fs/fs-writeback.c:2972
iput_final fs/inode.c:1950 [inline]
iput+0x8c1/0xe80 fs/inode.c:2009
jfs_umount+0x198/0x3d0 fs/jfs/jfs_umount.c:72
jfs_put_super+0x8c/0x190 fs/jfs/super.c:194
generic_shutdown_super+0x13d/0x2d0 fs/super.c:646
kill_block_super+0x44/0x90 fs/super.c:1725
deactivate_locked_super+0xbc/0x130 fs/super.c:476
cleanup_mnt+0x437/0x4d0 fs/namespace.c:1312
task_work_run+0x1d9/0x270 kernel/task_work.c:233
resume_user_mode_work include/linux/resume_user_mode.h:50 [inline]
__exit_to_user_mode_loop kernel/entry/common.c:67 [inline]
exit_to_user_mode_loop+0xed/0x480 kernel/entry/common.c:98
__exit_to_user_mode_prepare include/linux/irq-entry-common.h:238 [inline]
syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:269 [inline]
syscall_exit_to_user_mode include/linux/entry-common.h:328 [inline]
do_syscall_64+0x33e/0xf80 arch/x86/entry/syscall_64.c:100
entry_SYSCALL_64_after_hwframe+0x77/0x7f
other info that might help us debug this:
Possible unsafe locking scenario:
CPU0 CPU1
---- ----
lock(&(log)->loglock);
lock(&jfs_ip->commit_mutex);
lock(&(log)->loglock);
lock(&jfs_ip->commit_mutex);
*** DEADLOCK ***
2 locks held by syz-executor/5841:
#0: ffff888050f2c0d8 (&type->s_umount_key#87){+.+.}-{4:4}, at: __super_lock fs/super.c:58 [inline]
#0: ffff888050f2c0d8 (&type->s_umount_key#87){+.+.}-{4:4}, at: __super_lock_excl fs/super.c:73 [inline]
#0: ffff888050f2c0d8 (&type->s_umount_key#87){+.+.}-{4:4}, at: deactivate_super+0xa9/0xe0 fs/super.c:508
#1: ffff888035025918 (&(log)->loglock){+.+.}-{4:4}, at: jfs_umount+0x17f/0x3d0 fs/jfs/jfs_umount.c:66
stack backtrace:
CPU: 0 UID: 0 PID: 5841 Comm: syz-executor Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026
Call Trace:
<TASK>
dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120
print_circular_bug+0x2e1/0x300 kernel/locking/lockdep.c:2043
check_noncircular+0x12e/0x150 kernel/locking/lockdep.c:2175
check_prev_add kernel/locking/lockdep.c:3165 [inline]
check_prevs_add kernel/locking/lockdep.c:3284 [inline]
validate_chain kernel/locking/lockdep.c:3908 [inline]
__lock_acquire+0x15a5/0x2cf0 kernel/locking/lockdep.c:5237
lock_acquire+0x106/0x350 kernel/locking/lockdep.c:5868
__mutex_lock_common kernel/locking/mutex.c:632 [inline]
__mutex_lock+0x19e/0x1420 kernel/locking/mutex.c:794
jfs_commit_inode+0x1ca/0x530 fs/jfs/inode.c:108
jfs_write_inode+0x145/0x220 fs/jfs/inode.c:138
write_inode fs/fs-writeback.c:1582 [inline]
__writeback_single_inode+0x75a/0x10e0 fs/fs-writeback.c:1825
writeback_single_inode+0x4ac/0xdc0 fs/fs-writeback.c:1881
write_inode_now+0x1c2/0x290 fs/fs-writeback.c:2972
iput_final fs/inode.c:1950 [inline]
iput+0x8c1/0xe80 fs/inode.c:2009
jfs_umount+0x198/0x3d0 fs/jfs/jfs_umount.c:72
jfs_put_super+0x8c/0x190 fs/jfs/super.c:194
generic_shutdown_super+0x13d/0x2d0 fs/super.c:646
kill_block_super+0x44/0x90 fs/super.c:1725
deactivate_locked_super+0xbc/0x130 fs/super.c:476
cleanup_mnt+0x437/0x4d0 fs/namespace.c:1312
task_work_run+0x1d9/0x270 kernel/task_work.c:233
resume_user_mode_work include/linux/resume_user_mode.h:50 [inline]
__exit_to_user_mode_loop kernel/entry/common.c:67 [inline]
exit_to_user_mode_loop+0xed/0x480 kernel/entry/common.c:98
__exit_to_user_mode_prepare include/linux/irq-entry-common.h:238 [inline]
syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:269 [inline]
syscall_exit_to_user_mode include/linux/entry-common.h:328 [inline]
do_syscall_64+0x33e/0xf80 arch/x86/entry/syscall_64.c:100
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f2f0179da57
Code: a2 c7 05 9c fc 24 00 00 00 00 00 eb 96 e8 e1 12 00 00 90 31 f6 e9 09 00 00 00 66 0f 1f 84 00 00 00 00 00 b8 a6 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 01 c3 48 c7 c2 e8 ff ff ff f7 d8 64 89 02 b8
RSP: 002b:00007ffd82ab3bb8 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6
RAX: 0000000000000000 RBX: 00007f2f01832048 RCX: 00007f2f0179da57
RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007ffd82ab3c70
RBP: 00007ffd82ab3c70 R08: 00007ffd82ab4c70 R09: 00000000ffffffff
R10: 0000000000000000 R11: 0000000000000246 R12: 00007ffd82ab4d00
R13: 00007f2f01832048 R14: 000000000002faa3 R15: 00007ffd82ab4d40
</TASK>
| Time | Kernel | Commit | Syzkaller | Config | Log | Report | Syz repro | C repro | VM info | Assets (help?) | Manager | Title |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 2026/04/06 11:25 | linux-next | cc13002a9f98 | 4440e7c2 | .config | console log | report | info | [disk image] [vmlinux] [kernel image] | ci-upstream-linux-next-kasan-gce-root | possible deadlock in jfs_commit_inode | ||
| 2026/03/29 05:20 | linux-next | 3b058d1aeeef | 356bdfc9 | .config | console log | report | info | [disk image] [vmlinux] [kernel image] | ci-upstream-linux-next-kasan-gce-root | possible deadlock in jfs_commit_inode |