[v6.6] INFO: task hung in queue_log_writer

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: 5fa4793a2d2d Linux 6.6.119
git tree: linux-6.6.y
console output: https://syzkaller.appspot.com/x/log.txt?x=1054631a580000
kernel config: https://syzkaller.appspot.com/x/.config?x=691a6769a86ac817
dashboard link: https://syzkaller.appspot.com/bug?extid=28a7d93d7179659c8737
compiler: Debian clang version 20.1.8 (++20250708063551+0c9f909b7976-1~exp1~20250708183702.136), Debian LLD 20.1.8

Unfortunately, I don't have any reproducer for this issue yet.

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/63699875f1dd/disk-5fa4793a.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/8506652fcb6f/vmlinux-5fa4793a.xz
kernel image: https://storage.googleapis.com/syzbot-assets/1b30ceed1710/bzImage-5fa4793a.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+28a7d9...@syzkaller.appspotmail.com

INFO: task kworker/0:0:8 blocked for more than 144 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/0:0 state:D stack:22960 pid:8 ppid:2 flags:0x00004000
Workqueue: events_long flush_old_commits
Call Trace:
<TASK>
context_switch kernel/sched/core.c:5380 [inline]
__schedule+0x14d2/0x44d0 kernel/sched/core.c:6699
schedule+0xbd/0x170 kernel/sched/core.c:6773
queue_log_writer+0x1e8/0x2b0 fs/reiserfs/journal.c:2987
check_journal_end fs/reiserfs/journal.c:3681 [inline]
do_journal_end+0xa37/0x4860 fs/reiserfs/journal.c:4047
reiserfs_sync_fs fs/reiserfs/super.c:78 [inline]
flush_old_commits+0x213/0x2f0 fs/reiserfs/super.c:111
process_one_work kernel/workqueue.c:2634 [inline]
process_scheduled_works+0xa45/0x15b0 kernel/workqueue.c:2711
worker_thread+0xa55/0xfc0 kernel/workqueue.c:2792
kthread+0x2fa/0x390 kernel/kthread.c:388
ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152
ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293
</TASK>
INFO: task kworker/0:5:5852 blocked for more than 145 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/0:5 state:D stack:21656 pid:5852 ppid:2 flags:0x00004000
Workqueue: reiserfs/loop1 flush_async_commits
Call Trace:
<TASK>
context_switch kernel/sched/core.c:5380 [inline]
__schedule+0x14d2/0x44d0 kernel/sched/core.c:6699
schedule+0xbd/0x170 kernel/sched/core.c:6773
schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:6832
__mutex_lock_common kernel/locking/mutex.c:679 [inline]
__mutex_lock+0x6b7/0xcc0 kernel/locking/mutex.c:747
reiserfs_write_lock+0x79/0xd0 fs/reiserfs/lock.c:27
flush_async_commits+0x46/0xc0 fs/reiserfs/journal.c:3554
process_one_work kernel/workqueue.c:2634 [inline]
process_scheduled_works+0xa45/0x15b0 kernel/workqueue.c:2711
worker_thread+0xa55/0xfc0 kernel/workqueue.c:2792
kthread+0x2fa/0x390 kernel/kthread.c:388
ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152
ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293
</TASK>
INFO: task syz.2.216:6951 blocked for more than 145 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.2.216 state:D
stack:26000 pid:6951 ppid:5768 flags:0x00004006
Call Trace:
<TASK>
context_switch kernel/sched/core.c:5380 [inline]
__schedule+0x14d2/0x44d0 kernel/sched/core.c:6699
schedule+0xbd/0x170 kernel/sched/core.c:6773
schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:6832
__mutex_lock_common kernel/locking/mutex.c:679 [inline]
__mutex_lock+0x6b7/0xcc0 kernel/locking/mutex.c:747
reiserfs_write_lock_nested+0x60/0xd0 fs/reiserfs/lock.c:78
flush_commit_list+0x1253/0x1d80 fs/reiserfs/journal.c:1116
flush_older_commits fs/reiserfs/journal.c:919 [inline]
flush_commit_list+0x436/0x1d80 fs/reiserfs/journal.c:997
do_journal_end+0x3c8c/0x4860 fs/reiserfs/journal.c:4379
reiserfs_sync_fs+0xd0/0x150 fs/reiserfs/super.c:78
iterate_supers+0xb2/0x170 fs/super.c:979
ksys_sync+0xa4/0x150 fs/sync.c:103
__ia32_sys_sync+0xe/0x20 fs/sync.c:113
do_syscall_x64 arch/x86/entry/common.c:51 [inline]
do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:81
entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f442158f749
RSP: 002b:00007f4422387038 EFLAGS: 00000246
ORIG_RAX: 00000000000000a2
RAX: ffffffffffffffda RBX: 00007f44217e6090 RCX: 00007f442158f749
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007f44217e6090 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f44217e6128 R14: 00007f44217e6090 R15: 00007ffe40435858
</TASK>

Showing all locks held in the system:
1 lock held by pool_workqueue_/3:
#0: ffffffff8cd358f8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:324 [inline]
#0: ffffffff8cd358f8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x360/0x830 kernel/rcu/tree_exp.h:1004
3 locks held by kworker/0:0/8:
#0: ffff888017871138 ((wq_completion)events_long){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline]
#0: ffff888017871138 ((wq_completion)events_long){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711
#1: ffffc900000d7d00 ((work_completion)(&(&sbi->old_work)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline]
#1: ffffc900000d7d00 ((work_completion)(&(&sbi->old_work)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711
#2: ffff888056ddc0e0 (&type->s_umount_key#25){++++}-{3:3}, at: flush_old_commits+0xcc/0x2f0 fs/reiserfs/super.c:97
1 lock held by khungtaskd/29:
#0: ffffffff8cd2ff20 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:334 [inline]
#0: ffffffff8cd2ff20 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:786 [inline]
#0: ffffffff8cd2ff20 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x55/0x290 kernel/locking/lockdep.c:6633
3 locks held by kworker/u4:12/3549:
#0: ffff888019e67938 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline]
#0: ffff888019e67938 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711
#1: ffffc9000d397d00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline]
#1: ffffc9000d397d00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711
#2: ffff888056ddc0e0 (&type->s_umount_key#25){++++}-{3:3}, at: super_trylock_shared+0x20/0xf0 fs/super.c:607
2 locks held by getty/5536:
#0: ffff888030b0a0a0 (&tty->ldisc_sem){++++}-{0:0}
, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
#1:
ffffc9000328b2f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x425/0x1380 drivers/tty/n_tty.c:2217
3 locks held by kworker/0:5/5852:
#0: ffff888053c52138 ((wq_completion)reiserfs/loop1
){+.+.}-{0:0}
, at: process_one_work kernel/workqueue.c:2609 [inline]
, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711
#1: ffffc900049dfd00 ((work_completion)(&(&journal->j_work)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline]
#1: ffffc900049dfd00 ((work_completion)(&(&journal->j_work)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711
#2: ffff888024c49090 (&sbi->lock){+.+.}-{3:3}, at: reiserfs_write_lock+0x79/0xd0 fs/reiserfs/lock.c:27
9 locks held by syz.1.85/6188:
3 locks held by syz.2.216/6951:
#0: ffff888056ddc0e0 (&type->s_umount_key#25){++++}-{3:3}, at: __super_lock fs/super.c:58 [inline]
#0: ffff888056ddc0e0 (&type->s_umount_key#25){++++}-{3:3}, at: super_lock+0x167/0x360 fs/super.c:117
#1: ffff88802dc3c090 (&jl->j_commit_mutex){+.+.}-{3:3}, at: reiserfs_mutex_lock_safe fs/reiserfs/reiserfs.h:813 [inline]
#1: ffff88802dc3c090 (&jl->j_commit_mutex){+.+.}-{3:3}, at: flush_commit_list+0x6c8/0x1d80 fs/reiserfs/journal.c:1007
#2: ffff888024c49090 (&sbi->lock){+.+.}-{3:3}, at: reiserfs_write_lock_nested+0x60/0xd0 fs/reiserfs/lock.c:78
2 locks held by kworker/0:8/7828:
#0: ffff888017872538 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline]
#0: ffff888017872538 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711
#1: ffffc90004dafd00 ((work_completion)(&rew->rew_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline]
#1: ffffc90004dafd00 ((work_completion)(&rew->rew_work)){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711
2 locks held by syz-executor/8067:
#0: ffffffff8dfb5448 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:78 [inline]
#0: ffffffff8dfb5448 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x76f/0xf10 net/core/rtnetlink.c:6469
#1: ffffffff8cd358f8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:324 [inline]
#1: ffffffff8cd358f8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x360/0x830 kernel/rcu/tree_exp.h:1004


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