Re: [syzbot] [f2fs?] INFO: task hung in f2fs_release_file (3)

syzbot
2025-12-06T08:44:05Z

INFO: task syz.0.17:6598 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.0.17 state:D stack:26840 pid:6598 tgid:6598 ppid:6488 task_flags:0x400040 flags:0x00080002
Call Trace:
<TASK>
context_switch kernel/sched/core.c:5256 [inline]
__schedule+0x1480/0x50a0 kernel/sched/core.c:6863
__schedule_loop kernel/sched/core.c:6945 [inline]
rt_mutex_schedule+0x77/0xf0 kernel/sched/core.c:7241
rt_mutex_slowlock_block kernel/locking/rtmutex.c:1647 [inline]
__rt_mutex_slowlock kernel/locking/rtmutex.c:1721 [inline]
__rt_mutex_slowlock_locked+0x1dfe/0x25e0 kernel/locking/rtmutex.c:1760
rt_mutex_slowlock+0xb5/0x160 kernel/locking/rtmutex.c:1800
__rt_mutex_lock kernel/locking/rtmutex.c:1815 [inline]
rwbase_write_lock+0x14f/0x750 kernel/locking/rwbase_rt.c:244
inode_lock include/linux/fs.h:1027 [inline]
f2fs_release_file+0xe3/0x150 fs/f2fs/file.c:2063
__fput+0x45b/0xa80 fs/file_table.c:468
task_work_run+0x1d4/0x260 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:44 [inline]
exit_to_user_mode_loop+0xff/0x4f0 kernel/entry/common.c:75
__exit_to_user_mode_prepare include/linux/irq-entry-common.h:226 [inline]
syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:256 [inline]
syscall_exit_to_user_mode_work include/linux/entry-common.h:159 [inline]
syscall_exit_to_user_mode include/linux/entry-common.h:194 [inline]
do_syscall_64+0x2e3/0xf80 arch/x86/entry/syscall_64.c:100
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f1dccfff749
RSP: 002b:00007fff9df4ebb8 EFLAGS: 00000246 ORIG_RAX: 00000000000001b4
RAX: 0000000000000000 RBX: 00007f1dcd257da0 RCX: 00007f1dccfff749
RDX: 0000000000000000 RSI: 000000000000001e RDI: 0000000000000003
RBP: 00007f1dcd257da0 R08: 0000000000000000 R09: 000000069df4eeaf
R10: 00007f1dcd257cb0 R11: 0000000000000246 R12: 0000000000027b0d
R13: 00007fff9df4ecb0 R14: ffffffffffffffff R15: 00007fff9df4ecd0
</TASK>
INFO: task syz.0.17:6599 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.0.17 state:D stack:24488 pid:6599 tgid:6598 ppid:6488 task_flags:0x400140 flags:0x00080002
Call Trace:
<TASK>
context_switch kernel/sched/core.c:5256 [inline]
__schedule+0x1480/0x50a0 kernel/sched/core.c:6863
__schedule_loop kernel/sched/core.c:6945 [inline]
schedule+0x165/0x360 kernel/sched/core.c:6960
schedule_timeout+0x9a/0x270 kernel/time/sleep_timeout.c:75
do_wait_for_common kernel/sched/completion.c:100 [inline]
__wait_for_common kernel/sched/completion.c:121 [inline]
wait_for_common kernel/sched/completion.c:132 [inline]
wait_for_completion+0x2bf/0x5d0 kernel/sched/completion.c:153
f2fs_issue_checkpoint+0x382/0x610 fs/f2fs/checkpoint.c:-1
f2fs_unlink+0x5cb/0xa80 fs/f2fs/namei.c:603
vfs_unlink+0x386/0x650 fs/namei.c:5369
do_unlinkat+0x2cf/0x570 fs/namei.c:5439
__do_sys_unlinkat fs/namei.c:5469 [inline]
__se_sys_unlinkat fs/namei.c:5462 [inline]
__x64_sys_unlinkat+0xd3/0xf0 fs/namei.c:5462
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xfa/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f1dccfff749
RSP: 002b:00007f1dcc666038 EFLAGS: 00000246 ORIG_RAX: 0000000000000107
RAX: ffffffffffffffda RBX: 00007f1dcd255fa0 RCX: 00007f1dccfff749
RDX: 0000000000000000 RSI: 0000200000000040 RDI: ffffffffffffff9c
RBP: 00007f1dcd083f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f1dcd256038 R14: 00007f1dcd255fa0 R15: 00007fff9df4ea58
</TASK>
INFO: task syz.1.18:6626 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.1.18 state:D stack:26840 pid:6626 tgid:6626 ppid:6605 task_flags:0x400040 flags:0x00080002
Call Trace:
<TASK>
context_switch kernel/sched/core.c:5256 [inline]
__schedule+0x1480/0x50a0 kernel/sched/core.c:6863
__schedule_loop kernel/sched/core.c:6945 [inline]
rt_mutex_schedule+0x77/0xf0 kernel/sched/core.c:7241
rt_mutex_slowlock_block kernel/locking/rtmutex.c:1647 [inline]
__rt_mutex_slowlock kernel/locking/rtmutex.c:1721 [inline]
__rt_mutex_slowlock_locked+0x1dfe/0x25e0 kernel/locking/rtmutex.c:1760
rt_mutex_slowlock+0xb5/0x160 kernel/locking/rtmutex.c:1800
__rt_mutex_lock kernel/locking/rtmutex.c:1815 [inline]
rwbase_write_lock+0x14f/0x750 kernel/locking/rwbase_rt.c:244
inode_lock include/linux/fs.h:1027 [inline]
f2fs_release_file+0xe3/0x150 fs/f2fs/file.c:2063
__fput+0x45b/0xa80 fs/file_table.c:468
task_work_run+0x1d4/0x260 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:44 [inline]
exit_to_user_mode_loop+0xff/0x4f0 kernel/entry/common.c:75
__exit_to_user_mode_prepare include/linux/irq-entry-common.h:226 [inline]
syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:256 [inline]
syscall_exit_to_user_mode_work include/linux/entry-common.h:159 [inline]
syscall_exit_to_user_mode include/linux/entry-common.h:194 [inline]
do_syscall_64+0x2e3/0xf80 arch/x86/entry/syscall_64.c:100
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fdf96d9f749
RSP: 002b:00007fff745008d8 EFLAGS: 00000246 ORIG_RAX: 00000000000001b4
RAX: 0000000000000000 RBX: 00007fdf96ff7da0 RCX: 00007fdf96d9f749
RDX: 0000000000000000 RSI: 000000000000001e RDI: 0000000000000003
RBP: 00007fdf96ff7da0 R08: 0000000000000000 R09: 0000000674500bcf
R10: 00007fdf96ff7cb0 R11: 0000000000000246 R12: 000000000002c3b7
R13: 00007fff745009d0 R14: ffffffffffffffff R15: 00007fff745009f0
</TASK>
INFO: task syz.1.18:6627 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.1.18 state:D stack:24488 pid:6627 tgid:6626 ppid:6605 task_flags:0x400140 flags:0x00080002
Call Trace:
<TASK>
context_switch kernel/sched/core.c:5256 [inline]
__schedule+0x1480/0x50a0 kernel/sched/core.c:6863
__schedule_loop kernel/sched/core.c:6945 [inline]
schedule+0x165/0x360 kernel/sched/core.c:6960
schedule_timeout+0x9a/0x270 kernel/time/sleep_timeout.c:75
do_wait_for_common kernel/sched/completion.c:100 [inline]
__wait_for_common kernel/sched/completion.c:121 [inline]
wait_for_common kernel/sched/completion.c:132 [inline]
wait_for_completion+0x2bf/0x5d0 kernel/sched/completion.c:153
f2fs_issue_checkpoint+0x382/0x610 fs/f2fs/checkpoint.c:-1
f2fs_unlink+0x5cb/0xa80 fs/f2fs/namei.c:603
vfs_unlink+0x386/0x650 fs/namei.c:5369
do_unlinkat+0x2cf/0x570 fs/namei.c:5439
__do_sys_unlinkat fs/namei.c:5469 [inline]
__se_sys_unlinkat fs/namei.c:5462 [inline]
__x64_sys_unlinkat+0xd3/0xf0 fs/namei.c:5462
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xfa/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fdf96d9f749
RSP: 002b:00007fdf96406038 EFLAGS: 00000246 ORIG_RAX: 0000000000000107
RAX: ffffffffffffffda RBX: 00007fdf96ff5fa0 RCX: 00007fdf96d9f749
RDX: 0000000000000000 RSI: 0000200000000040 RDI: ffffffffffffff9c
RBP: 00007fdf96e23f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fdf96ff6038 R14: 00007fdf96ff5fa0 R15: 00007fff74500778
</TASK>

Showing all locks held in the system:
3 locks held by kworker/u8:0/12:
#0: ffff888140464138 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3232 [inline]
#0: ffff888140464138 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x1770 kernel/workqueue.c:3340
#1: ffffc90000117b80 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3233 [inline]
#1: ffffc90000117b80 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x1770 kernel/workqueue.c:3340
#2: ffff8880306fc0d0 (&type->s_umount_key#55){++++}-{4:4}, at: super_trylock_shared+0x20/0xf0 fs/super.c:563
1 lock held by khungtaskd/38:
#0: ffffffff8d5aecc0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
#0: ffffffff8d5aecc0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline]
#0: ffffffff8d5aecc0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775
3 locks held by kworker/u8:5/81:
#0: ffff888140464138 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3232 [inline]
#0: ffff888140464138 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x1770 kernel/workqueue.c:3340
#1: ffffc9000159fb80 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3233 [inline]
#1: ffffc9000159fb80 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x1770 kernel/workqueue.c:3340
#2: ffff88801ead60d0 (&type->s_umount_key#55){++++}-{4:4}, at: super_trylock_shared+0x20/0xf0 fs/super.c:563
3 locks held by kworker/u8:6/808:
3 locks held by kworker/u8:10/1551:
#0: ffff888140464138 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3232 [inline]
#0: ffff888140464138 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x1770 kernel/workqueue.c:3340
#1: ffffc9000520fb80 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3233 [inline]
#1: ffffc9000520fb80 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x1770 kernel/workqueue.c:3340
#2: ffff88803bbc20d0 (&type->s_umount_key#55){++++}-{4:4}, at: super_trylock_shared+0x20/0xf0 fs/super.c:563
3 locks held by kworker/u8:14/3678:
#0: ffff888140464138 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3232 [inline]
#0: ffff888140464138 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x1770 kernel/workqueue.c:3340
#1: ffffc9000d187b80 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3233 [inline]
#1: ffffc9000d187b80 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x1770 kernel/workqueue.c:3340
#2: ffff8880276640d0 (&type->s_umount_key#55){++++}-{4:4}, at: super_trylock_shared+0x20/0xf0 fs/super.c:563
2 locks held by getty/5560:
#0: ffff8880268520a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
#1: ffffc90003e8b2e0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x444/0x1400 drivers/tty/n_tty.c:2222
1 lock held by syz.0.17/6598:
#0: ffff888051658178 (&sb->s_type->i_mutex_key#23){+.+.}-{4:4}, at: inode_lock include/linux/fs.h:1027 [inline]
#0: ffff888051658178 (&sb->s_type->i_mutex_key#23){+.+.}-{4:4}, at: f2fs_release_file+0xe3/0x150 fs/f2fs/file.c:2063
3 locks held by syz.0.17/6599:
#0: ffff88803bbc2480 (sb_writers#12){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:499
#1: ffff888051681478 (&type->i_mutex_dir_key#8/1){+.+.}-{4:4}, at: inode_lock_nested include/linux/fs.h:1072 [inline]
#1: ffff888051681478 (&type->i_mutex_dir_key#8/1){+.+.}-{4:4}, at: __start_dirop fs/namei.c:2864 [inline]
#1: ffff888051681478 (&type->i_mutex_dir_key#8/1){+.+.}-{4:4}, at: start_dirop fs/namei.c:2875 [inline]
#1: ffff888051681478 (&type->i_mutex_dir_key#8/1){+.+.}-{4:4}, at: do_unlinkat+0x1b2/0x570 fs/namei.c:5420
#2: ffff888051658178 (&sb->s_type->i_mutex_key#23){+.+.}-{4:4}, at: inode_lock include/linux/fs.h:1027 [inline]
#2: ffff888051658178 (&sb->s_type->i_mutex_key#23){+.+.}-{4:4}, at: vfs_unlink+0xef/0x650 fs/namei.c:5355
4 locks held by f2fs_ckpt-7:0/6603:
1 lock held by syz.1.18/6626:
#0: ffff888051659df8 (&sb->s_type->i_mutex_key#23){+.+.}-{4:4}, at: inode_lock include/linux/fs.h:1027 [inline]
#0: ffff888051659df8 (&sb->s_type->i_mutex_key#23){+.+.}-{4:4}, at: f2fs_release_file+0xe3/0x150 fs/f2fs/file.c:2063
3 locks held by syz.1.18/6627:
#0: ffff888027664480 (sb_writers#12){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:499
#1: ffff888051659478 (&type->i_mutex_dir_key#8/1){+.+.}-{4:4}, at: inode_lock_nested include/linux/fs.h:1072 [inline]
#1: ffff888051659478 (&type->i_mutex_dir_key#8/1){+.+.}-{4:4}, at: __start_dirop fs/namei.c:2864 [inline]
#1: ffff888051659478 (&type->i_mutex_dir_key#8/1){+.+.}-{4:4}, at: start_dirop fs/namei.c:2875 [inline]
#1: ffff888051659478 (&type->i_mutex_dir_key#8/1){+.+.}-{4:4}, at: do_unlinkat+0x1b2/0x570 fs/namei.c:5420
#2: ffff888051659df8 (&sb->s_type->i_mutex_key#23){+.+.}-{4:4}, at: inode_lock include/linux/fs.h:1027 [inline]
#2: ffff888051659df8 (&sb->s_type->i_mutex_key#23){+.+.}-{4:4}, at: vfs_unlink+0xef/0x650 fs/namei.c:5355
4 locks held by f2fs_ckpt-7:1/6631:
1 lock held by syz.2.19/6659:
#0: ffff8880516843f8 (&sb->s_type->i_mutex_key#23){+.+.}-{4:4}, at: inode_lock include/linux/fs.h:1027 [inline]
#0: ffff8880516843f8 (&sb->s_type->i_mutex_key#23){+.+.}-{4:4}, at: f2fs_release_file+0xe3/0x150 fs/f2fs/file.c:2063
3 locks held by syz.2.19/6660:
#0: ffff8880306fc480 (sb_writers#12){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:499
#1: ffff888051683a78 (&type->i_mutex_dir_key#8/1){+.+.}-{4:4}, at: inode_lock_nested include/linux/fs.h:1072 [inline]
#1: ffff888051683a78 (&type->i_mutex_dir_key#8/1){+.+.}-{4:4}, at: __start_dirop fs/namei.c:2864 [inline]
#1: ffff888051683a78 (&type->i_mutex_dir_key#8/1){+.+.}-{4:4}, at: start_dirop fs/namei.c:2875 [inline]
#1: ffff888051683a78 (&type->i_mutex_dir_key#8/1){+.+.}-{4:4}, at: do_unlinkat+0x1b2/0x570 fs/namei.c:5420
#2: ffff8880516843f8 (&sb->s_type->i_mutex_key#23){+.+.}-{4:4}, at: inode_lock include/linux/fs.h:1027 [inline]
#2: ffff8880516843f8 (&sb->s_type->i_mutex_key#23){+.+.}-{4:4}, at: vfs_unlink+0xef/0x650 fs/namei.c:5355
2 locks held by f2fs_ckpt-7:2/6664:
1 lock held by syz.3.20/6689:
#0: ffff8880516856f8 (&sb->s_type->i_mutex_key#23){+.+.}-{4:4}, at: inode_lock include/linux/fs.h:1027 [inline]
#0: ffff8880516856f8 (&sb->s_type->i_mutex_key#23){+.+.}-{4:4}, at: f2fs_release_file+0xe3/0x150 fs/f2fs/file.c:2063
3 locks held by syz.3.20/6690:
#0: ffff88801ef30480 (sb_writers#12){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:499
#1: ffff88805165b0f8 (&type->i_mutex_dir_key#8/1){+.+.}-{4:4}, at: inode_lock_nested include/linux/fs.h:1072 [inline]
#1: ffff88805165b0f8 (&type->i_mutex_dir_key#8/1){+.+.}-{4:4}, at: __start_dirop fs/namei.c:2864 [inline]
#1: ffff88805165b0f8 (&type->i_mutex_dir_key#8/1){+.+.}-{4:4}, at: start_dirop fs/namei.c:2875 [inline]
#1: ffff88805165b0f8 (&type->i_mutex_dir_key#8/1){+.+.}-{4:4}, at: do_unlinkat+0x1b2/0x570 fs/namei.c:5420
#2: ffff8880516856f8 (&sb->s_type->i_mutex_key#23){+.+.}-{4:4}, at: inode_lock include/linux/fs.h:1027 [inline]
#2: ffff8880516856f8 (&sb->s_type->i_mutex_key#23){+.+.}-{4:4}, at: vfs_unlink+0xef/0x650 fs/namei.c:5355
5 locks held by f2fs_ckpt-7:3/6694:
1 lock held by syz.4.21/6724:
#0: ffff88805165ba78 (&sb->s_type->i_mutex_key#23){+.+.}-{4:4}, at: inode_lock include/linux/fs.h:1027 [inline]
#0: ffff88805165ba78 (&sb->s_type->i_mutex_key#23){+.+.}-{4:4}, at: f2fs_release_file+0xe3/0x150 fs/f2fs/file.c:2063
3 locks held by syz.4.21/6725:
#0: ffff88801ead6480 (sb_writers#12){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:499
#1: ffff888051687378 (&type->i_mutex_dir_key#8/1){+.+.}-{4:4}, at: inode_lock_nested include/linux/fs.h:1072 [inline]
#1: ffff888051687378 (&type->i_mutex_dir_key#8/1){+.+.}-{4:4}, at: __start_dirop fs/namei.c:2864 [inline]
#1: ffff888051687378 (&type->i_mutex_dir_key#8/1){+.+.}-{4:4}, at: start_dirop fs/namei.c:2875 [inline]
#1: ffff888051687378 (&type->i_mutex_dir_key#8/1){+.+.}-{4:4}, at: do_unlinkat+0x1b2/0x570 fs/namei.c:5420
#2: ffff88805165ba78 (&sb->s_type->i_mutex_key#23){+.+.}-{4:4}, at: inode_lock include/linux/fs.h:1027 [inline]
#2: ffff88805165ba78 (&sb->s_type->i_mutex_key#23){+.+.}-{4:4}, at: vfs_unlink+0xef/0x650 fs/namei.c:5355
3 locks held by f2fs_ckpt-7:4/6732:
1 lock held by syz.5.22/6770:
#0: ffff88805165d6f8 (&sb->s_type->i_mutex_key#23){+.+.}-{4:4}, at: inode_lock include/linux/fs.h:1027 [inline]
#0: ffff88805165d6f8 (&sb->s_type->i_mutex_key#23){+.+.}-{4:4}, at: f2fs_release_file+0xe3/0x150 fs/f2fs/file.c:2063
3 locks held by syz.5.22/6771:
#0: ffff888028b5c480 (sb_writers#12){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:499
#1: ffff88805165cd78 (&type->i_mutex_dir_key#8/1){+.+.}-{4:4}, at: inode_lock_nested include/linux/fs.h:1072 [inline]
#1: ffff88805165cd78 (&type->i_mutex_dir_key#8/1){+.+.}-{4:4}, at: __start_dirop fs/namei.c:2864 [inline]
#1: ffff88805165cd78 (&type->i_mutex_dir_key#8/1){+.+.}-{4:4}, at: start_dirop fs/namei.c:2875 [inline]
#1: ffff88805165cd78 (&type->i_mutex_dir_key#8/1){+.+.}-{4:4}, at: do_unlinkat+0x1b2/0x570 fs/namei.c:5420
#2: ffff88805165d6f8 (&sb->s_type->i_mutex_key#23){+.+.}-{4:4}, at: inode_lock include/linux/fs.h:1027 [inline]
#2: ffff88805165d6f8 (&sb->s_type->i_mutex_key#23){+.+.}-{4:4}, at: vfs_unlink+0xef/0x650 fs/namei.c:5355
4 locks held by f2fs_ckpt-7:5/6775:
3 locks held by kworker/u8:20/6778:
#0: ffff888140464138 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3232 [inline]
#0: ffff888140464138 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x1770 kernel/workqueue.c:3340
#1: ffffc90004eafb80 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3233 [inline]
#1: ffffc90004eafb80 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x1770 kernel/workqueue.c:3340
#2: ffff88801ef300d0 (&type->s_umount_key#55){++++}-{4:4}, at: super_trylock_shared+0x20/0xf0 fs/super.c:563
1 lock held by syz.6.23/6814:
#0: ffff888058210178 (&sb->s_type->i_mutex_key#23){+.+.}-{4:4}, at: inode_lock include/linux/fs.h:1027 [inline]
#0: ffff888058210178 (&sb->s_type->i_mutex_key#23){+.+.}-{4:4}, at: f2fs_release_file+0xe3/0x150 fs/f2fs/file.c:2063
3 locks held by syz.6.23/6815:
#0: ffff8880397e0480 (sb_writers#12){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:499
#1: ffff88805165f378 (&type->i_mutex_dir_key#8/1){+.+.}-{4:4}, at: inode_lock_nested include/linux/fs.h:1072 [inline]
#1: ffff88805165f378 (&type->i_mutex_dir_key#8/1){+.+.}-{4:4}, at: __start_dirop fs/namei.c:2864 [inline]
#1: ffff88805165f378 (&type->i_mutex_dir_key#8/1){+.+.}-{4:4}, at: start_dirop fs/namei.c:2875 [inline]
#1: ffff88805165f378 (&type->i_mutex_dir_key#8/1){+.+.}-{4:4}, at: do_unlinkat+0x1b2/0x570 fs/namei.c:5420
#2: ffff888058210178 (&sb->s_type->i_mutex_key#23){+.+.}-{4:4}, at: inode_lock include/linux/fs.h:1027 [inline]
#2: ffff888058210178 (&sb->s_type->i_mutex_key#23){+.+.}-{4:4}, at: vfs_unlink+0xef/0x650 fs/namei.c:5355
4 locks held by f2fs_ckpt-7:6/6820:
6 locks held by syz-executor/6829:

=============================================

NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 38 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT_{RT,(full)}
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
Call Trace:
<TASK>
dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120
nmi_cpu_backtrace+0x39e/0x3d0 lib/nmi_backtrace.c:113
nmi_trigger_cpumask_backtrace+0x17a/0x300 lib/nmi_backtrace.c:62
trigger_all_cpu_backtrace include/linux/nmi.h:160 [inline]
check_hung_uninterruptible_tasks kernel/hung_task.c:332 [inline]
watchdog+0xf3c/0xf80 kernel/hung_task.c:495
kthread+0x711/0x8a0 kernel/kthread.c:463
ret_from_fork+0x599/0xb30 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246
</TASK>
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 808 Comm: kworker/u8:6 Not tainted syzkaller #0 PREEMPT_{RT,(full)}
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
Workqueue: events_unbound nsim_dev_trap_report_work
RIP: 0010:__bfs kernel/locking/lockdep.c:1815 [inline]
RIP: 0010:__bfs_backwards kernel/locking/lockdep.c:1860 [inline]
RIP: 0010:check_irq_usage kernel/locking/lockdep.c:2796 [inline]
RIP: 0010:check_prev_add kernel/locking/lockdep.c:3169 [inline]
RIP: 0010:check_prevs_add kernel/locking/lockdep.c:3284 [inline]
RIP: 0010:validate_chain kernel/locking/lockdep.c:3908 [inline]
RIP: 0010:__lock_acquire+0x197c/0x2cf0 kernel/locking/lockdep.c:5237
Code: 13 25 ff 0f 00 00 39 05 9e 87 17 11 73 06 89 05 96 87 17 11 48 8b 02 48 89 df 4c 39 e8 0f 84 2c fe ff ff 4c 89 60 30 48 8b 00 <4c> 39 e8 75 f4 48 89 df e9 18 fe ff ff 48 89 fb 48 c7 c7 10 e4 47
RSP: 0018:ffffc900042370b8 EFLAGS: 00000002
RAX: ffffffff95556ad8 RBX: 00000000000003cc RCX: 00000000000000a9
RDX: ffffffff953bcee8 RSI: ffff8880240d0ca8 RDI: 00000000000003cc
RBP: 233744c3de05d782 R08: ffffc90004237080 R09: 0000000000000020
R10: dffffc0000000000 R11: ffffffff819d54f0 R12: ffffffff9540f898
R13: ffffffff9257f330 R14: ffff8880240d0000 R15: 00000000000000a8
FS: 0000000000000000(0000) GS:ffff888126d52000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f1748c6f000 CR3: 0000000036390000 CR4: 00000000003526f0
Call Trace:
<TASK>
lock_acquire+0x117/0x340 kernel/locking/lockdep.c:5868
__raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
_raw_spin_lock_irqsave+0xa7/0xf0 kernel/locking/spinlock.c:162
rtlock_slowlock kernel/locking/rtmutex.c:1894 [inline]
rtlock_lock kernel/locking/spinlock_rt.c:43 [inline]
__rt_spin_lock kernel/locking/spinlock_rt.c:49 [inline]
rt_spin_lock+0x14a/0x3e0 kernel/locking/spinlock_rt.c:57
spin_lock include/linux/spinlock_rt.h:44 [inline]
__folio_end_writeback+0x157/0x760 mm/page-writeback.c:2990
folio_end_writeback_no_dropbehind+0x151/0x290 mm/filemap.c:1661
folio_end_writeback+0xea/0x220 mm/filemap.c:1687
f2fs_write_end_io+0x7ba/0xb60 fs/f2fs/data.c:362
blk_update_request+0x57e/0xe60 block/blk-mq.c:1006
blk_mq_end_request+0x3e/0x70 block/blk-mq.c:1168
blk_complete_reqs block/blk-mq.c:1243 [inline]
blk_done_softirq+0x10a/0x160 block/blk-mq.c:1248
handle_softirqs+0x226/0x6d0 kernel/softirq.c:622
__do_softirq kernel/softirq.c:656 [inline]
__local_bh_enable_ip+0x1a0/0x2e0 kernel/softirq.c:302
local_bh_enable include/linux/bottom_half.h:33 [inline]
__alloc_skb+0x224/0x430 net/core/skbuff.c:674
alloc_skb include/linux/skbuff.h:1383 [inline]
nsim_dev_trap_skb_build drivers/net/netdevsim/dev.c:818 [inline]
nsim_dev_trap_report drivers/net/netdevsim/dev.c:875 [inline]
nsim_dev_trap_report_work+0x29f/0xbc0 drivers/net/netdevsim/dev.c:921
process_one_work kernel/workqueue.c:3257 [inline]
process_scheduled_works+0xad1/0x1770 kernel/workqueue.c:3340
worker_thread+0x8a0/0xda0 kernel/workqueue.c:3421
kthread+0x711/0x8a0 kernel/kthread.c:463
ret_from_fork+0x599/0xb30 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246
</TASK>
F2FS-fs (loop7): inject read IO error in f2fs_read_end_io of blk_update_request+0x57e/0xe60 block/blk-mq.c:1006
F2FS-fs (loop7): inject read IO error in f2fs_read_end_io of blk_update_request+0x57e/0xe60 block/blk-mq.c:1006

Tested on:

commit: 416f99c3 Merge tag 'driver-core-6.19-rc1' of git://git..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=119b821a580000
kernel config: https://syzkaller.appspot.com/x/.config?x=8c04d4527fc98ffa
dashboard link: https://syzkaller.appspot.com/bug?extid=4235e4d7b6fd75704528
compiler: Debian clang version 20.1.8 (++20250708063551+0c9f909b7976-1~exp1~20250708183702.136), Debian LLD 20.1.8
patch: https://syzkaller.appspot.com/x/patch.diff?x=17000eb4580000