[v5.15] INFO: task hung in flush_old_commits

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: 8020ae3c051d Linux 5.15.103
git tree: linux-5.15.y
console output: https://syzkaller.appspot.com/x/log.txt?x=108069f6c80000
kernel config: https://syzkaller.appspot.com/x/.config?x=f95b212e0ccdd4d1
dashboard link: https://syzkaller.appspot.com/bug?extid=bd77ba23a65c1739f0b4
compiler: Debian clang version 15.0.7, GNU ld (GNU Binutils for Debian) 2.35.2
userspace arch: arm64

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

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/6153dfa8dcc0/disk-8020ae3c.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/2093d52db59f/vmlinux-8020ae3c.xz
kernel image: https://storage.googleapis.com/syzbot-assets/85041d0bd356/Image-8020ae3c.gz.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+bd77ba...@syzkaller.appspotmail.com

INFO: task kworker/1:0:21 blocked for more than 143 seconds.
Not tainted 5.15.103-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/1:0 state:D stack: 0 pid: 21 ppid: 2 flags:0x00000008
Workqueue: events_long flush_old_commits
Call trace:
__switch_to+0x308/0x5e8 arch/arm64/kernel/process.c:518
context_switch kernel/sched/core.c:5023 [inline]
__schedule+0xfcc/0x1f1c kernel/sched/core.c:6369
schedule+0x11c/0x1c8 kernel/sched/core.c:6452
schedule_preempt_disabled+0x18/0x2c kernel/sched/core.c:6511
__mutex_lock_common+0xba0/0x2154 kernel/locking/mutex.c:669
__mutex_lock kernel/locking/mutex.c:729 [inline]
mutex_lock_nested+0xa4/0xf8 kernel/locking/mutex.c:743
reiserfs_write_lock+0x7c/0xe8 fs/reiserfs/lock.c:27
reiserfs_sync_fs fs/reiserfs/super.c:76 [inline]
flush_old_commits+0x1b0/0x2b8 fs/reiserfs/super.c:111
process_one_work+0x84c/0x14b8 kernel/workqueue.c:2306
worker_thread+0x910/0x1034 kernel/workqueue.c:2453
kthread+0x37c/0x45c kernel/kthread.c:319
ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:870
INFO: task syz-executor.2:10647 blocked for more than 143 seconds.
Not tainted 5.15.103-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor.2 state:D stack: 0 pid:10647 ppid: 4098 flags:0x00000009
Call trace:
__switch_to+0x308/0x5e8 arch/arm64/kernel/process.c:518
context_switch kernel/sched/core.c:5023 [inline]
__schedule+0xfcc/0x1f1c kernel/sched/core.c:6369
schedule+0x11c/0x1c8 kernel/sched/core.c:6452
schedule_preempt_disabled+0x18/0x2c kernel/sched/core.c:6511
__mutex_lock_common+0xba0/0x2154 kernel/locking/mutex.c:669
__mutex_lock kernel/locking/mutex.c:729 [inline]
mutex_lock_nested+0xa4/0xf8 kernel/locking/mutex.c:743
reiserfs_write_lock+0x7c/0xe8 fs/reiserfs/lock.c:27
reiserfs_ioctl+0x74/0x4b8 fs/reiserfs/ioctl.c:81
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:874 [inline]
__se_sys_ioctl fs/ioctl.c:860 [inline]
__arm64_sys_ioctl+0x14c/0x1c8 fs/ioctl.c:860
__invoke_syscall arch/arm64/kernel/syscall.c:38 [inline]
invoke_syscall+0x98/0x2b8 arch/arm64/kernel/syscall.c:52
el0_svc_common+0x138/0x258 arch/arm64/kernel/syscall.c:142
do_el0_svc+0x58/0x14c arch/arm64/kernel/syscall.c:181
el0_svc+0x7c/0x1f0 arch/arm64/kernel/entry-common.c:596
el0t_64_sync_handler+0x84/0xe4 arch/arm64/kernel/entry-common.c:614
el0t_64_sync+0x1a0/0x1a4 arch/arm64/kernel/entry.S:584

Showing all locks held in the system:
2 locks held by kworker/u4:0/9:
#0: ffff0000c0029138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work+0x66c/0x14b8 kernel/workqueue.c:2279
#1: ffff8000189c7c00 ((work_completion)(&sub_info->work)){+.+.}-{0:0}, at: process_one_work+0x6ac/0x14b8 kernel/workqueue.c:2281
4 locks held by kworker/1:0/21:
#0: ffff0000c0021538 ((wq_completion)events_long){+.+.}-{0:0}, at: process_one_work+0x66c/0x14b8 kernel/workqueue.c:2279
#1: ffff800018a97c00 ((work_completion)(&(&sbi->old_work)->work)){+.+.}-{0:0}, at: process_one_work+0x6ac/0x14b8 kernel/workqueue.c:2281
#2: ffff0000c0fa80e0 (&type->s_umount_key#79){++++}-{3:3}, at: flush_old_commits+0xcc/0x2b8 fs/reiserfs/super.c:97
#3: ffff000116a93090 (&sbi->lock){+.+.}-{3:3}, at: reiserfs_write_lock+0x7c/0xe8 fs/reiserfs/lock.c:27
1 lock held by khungtaskd/27:
#0: ffff800014b92620 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0xc/0x44 include/linux/rcupdate.h:268
2 locks held by kworker/u4:3/292:
#0: ffff0000c0029138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work+0x66c/0x14b8 kernel/workqueue.c:2279
#1: ffff80001c727c00 ((work_completion)(&sub_info->work)){+.+.}-{0:0}, at: process_one_work+0x6ac/0x14b8 kernel/workqueue.c:2281
3 locks held by kworker/u4:6/442:
2 locks held by kworker/u4:7/455:
#0: ffff0000c0029138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work+0x66c/0x14b8 kernel/workqueue.c:2279
#1: ffff0001b4802c48 (&per_cpu_ptr(group->pcpu, cpu)->seq){-.-.}-{0:0}, at: psi_task_switch+0x438/0x66c kernel/sched/psi.c:891
1 lock held by udevd/3586:
2 locks held by getty/3740:
#0: ffff0000d10e7098 (&tty->ldisc_sem){++++}-{0:0}, at: ldsem_down_read+0x40/0x50 drivers/tty/tty_ldsem.c:340
#1: ffff800018ea02e8 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x414/0x1200 drivers/tty/n_tty.c:2147
2 locks held by syz-executor.3/4088:
1 lock held by syz-executor.1/4096:
2 locks held by kworker/u4:9/7844:
4 locks held by syz-executor.2/10614:
1 lock held by syz-executor.2/10647:
#0: ffff000116a93090 (&sbi->lock){+.+.}-{3:3}, at: reiserfs_write_lock+0x7c/0xe8 fs/reiserfs/lock.c:27
2 locks held by syz-executor.2/10679:
1 lock held by syz-executor.5/14446:
#0: ffff0000dfb40810 (&sb->s_type->i_mutex_key#11){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:787 [inline]
#0: ffff0000dfb40810 (&sb->s_type->i_mutex_key#11){+.+.}-{3:3}, at: __sock_release net/socket.c:648 [inline]
#0: ffff0000dfb40810 (&sb->s_type->i_mutex_key#11){+.+.}-{3:3}, at: sock_close+0x80/0x1fc net/socket.c:1317
1 lock held by syz-executor.1/14454:

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



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[syzbot]

syzbot has found a reproducer for the following issue on:

HEAD commit: 9d6bde853685 Linux 5.15.112
git tree: linux-5.15.y
console output: https://syzkaller.appspot.com/x/log.txt?x=17607e41280000
kernel config: https://syzkaller.appspot.com/x/.config?x=508f7a387ef8f82b

dashboard link: https://syzkaller.appspot.com/bug?extid=bd77ba23a65c1739f0b4
compiler: Debian clang version 15.0.7, GNU ld (GNU Binutils for Debian) 2.35.2
userspace arch: arm64

syz repro: https://syzkaller.appspot.com/x/repro.syz?x=156226ee280000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=11997af9280000

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/a8ab2bd416bb/disk-9d6bde85.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/c358e3d58bb2/vmlinux-9d6bde85.xz
kernel image: https://storage.googleapis.com/syzbot-assets/c82319bbaeb8/Image-9d6bde85.gz.xz
mounted in repro: https://storage.googleapis.com/syzbot-assets/60c308a4e085/mount_1.gz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+bd77ba...@syzkaller.appspotmail.com

INFO: task kworker/0:2:3763 blocked for more than 143 seconds.
Not tainted 5.15.112-syzkaller #0

"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.

task:kworker/0:2 state:D stack: 0 pid: 3763 ppid: 2 flags:0x00000008

Workqueue: events_long flush_old_commits

Call trace:
__switch_to+0x308/0x5e8 arch/arm64/kernel/process.c:518

context_switch kernel/sched/core.c:5026 [inline]
__schedule+0xf10/0x1e38 kernel/sched/core.c:6372
schedule+0x11c/0x1c8 kernel/sched/core.c:6455
schedule_preempt_disabled+0x18/0x2c kernel/sched/core.c:6514

__mutex_lock_common+0xba0/0x2154 kernel/locking/mutex.c:669
__mutex_lock kernel/locking/mutex.c:729 [inline]
mutex_lock_nested+0xa4/0xf8 kernel/locking/mutex.c:743
reiserfs_write_lock+0x7c/0xe8 fs/reiserfs/lock.c:27
reiserfs_sync_fs fs/reiserfs/super.c:76 [inline]
flush_old_commits+0x1b0/0x2b8 fs/reiserfs/super.c:111

process_one_work+0x790/0x11b8 kernel/workqueue.c:2307
worker_thread+0x910/0x1034 kernel/workqueue.c:2454

kthread+0x37c/0x45c kernel/kthread.c:319
ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:870

Showing all locks held in the system:

1 lock held by khungtaskd/27:
#0:

ffff800014aa19e0
(
rcu_read_lock

){....}-{1:2}
, at: rcu_lock_acquire+0xc/0x44 include/linux/rcupdate.h:268

2 locks held by getty/3724:
#0: ffff0000d2f5e098 (&tty->ldisc_sem){++++}-{0:0}, at: ldsem_down_read+0x40/0x50 drivers/tty/tty_ldsem.c:340
#1:
ffff80001a27b2e8
(
&ldata->atomic_read_lock

){+.+.}-{3:3}
, at: n_tty_read+0x414/0x1200 drivers/tty/n_tty.c:2147

4 locks held by kworker/0:2/3763:
#0:
ffff0000c0021538
(
(wq_completion)events_long

){+.+.}-{0:0}

, at: process_one_work+0x66c/0x11b8 kernel/workqueue.c:2280
#1:
ffff80001c9c7c00
(
(work_completion)(&(&sbi->old_work)->work)

){+.+.}-{0:0}

, at: process_one_work+0x6ac/0x11b8 kernel/workqueue.c:2282
#2:
ffff0000cb2c60e0 (&type->s_umount_key#40){++++}-{3:3}, at: flush_old_commits+0xcc/0x2b8 fs/reiserfs/super.c:97
#3: ffff0000dd602090 (&sbi->lock){+.+.}-{3:3}, at: reiserfs_write_lock+0x7c/0xe8 fs/reiserfs/lock.c:27
6 locks held by syz-executor238/3999:

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



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