[v6.1] INFO: task hung in coredump_task_exit (2)

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: 8b4118fabd6e Linux 6.1.78
git tree: linux-6.1.y
console output: https://syzkaller.appspot.com/x/log.txt?x=11f2604a180000
kernel config: https://syzkaller.appspot.com/x/.config?x=88ef89f70d190671
dashboard link: https://syzkaller.appspot.com/bug?extid=508684b94dabb81b8dbe
compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40
userspace arch: arm64

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

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/081869225fc6/disk-8b4118fa.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/d2352caf51d2/vmlinux-8b4118fa.xz
kernel image: https://storage.googleapis.com/syzbot-assets/43ad130ed88b/Image-8b4118fa.gz.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+508684...@syzkaller.appspotmail.com

INFO: task syz-executor.4:23870 blocked for more than 143 seconds.
Not tainted 6.1.78-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor.4 state:D stack:0 pid:23870 ppid:4266 flags:0x0000000d
Call trace:
__switch_to+0x320/0x754 arch/arm64/kernel/process.c:553
context_switch kernel/sched/core.c:5245 [inline]
__schedule+0xee4/0x1c98 kernel/sched/core.c:6558
schedule+0xc4/0x170 kernel/sched/core.c:6634
coredump_task_exit+0x278/0x394 kernel/exit.c:432
do_exit+0x1b8/0x1a88 kernel/exit.c:819
do_group_exit+0x194/0x22c kernel/exit.c:1019
get_signal+0x14a0/0x158c kernel/signal.c:2862
do_signal arch/arm64/kernel/signal.c:1076 [inline]
do_notify_resume+0x3ac/0x3474 arch/arm64/kernel/signal.c:1129
prepare_exit_to_user_mode arch/arm64/kernel/entry-common.c:137 [inline]
exit_to_user_mode arch/arm64/kernel/entry-common.c:142 [inline]
el0_svc+0x9c/0x168 arch/arm64/kernel/entry-common.c:638
el0t_64_sync_handler+0x84/0xf0 arch/arm64/kernel/entry-common.c:655
el0t_64_sync+0x18c/0x190 arch/arm64/kernel/entry.S:585
INFO: task syz-executor.4:23871 blocked for more than 143 seconds.
Not tainted 6.1.78-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor.4 state:D stack:0 pid:23871 ppid:4266 flags:0x0000000d
Call trace:
__switch_to+0x320/0x754 arch/arm64/kernel/process.c:553
context_switch kernel/sched/core.c:5245 [inline]
__schedule+0xee4/0x1c98 kernel/sched/core.c:6558
schedule+0xc4/0x170 kernel/sched/core.c:6634
coredump_task_exit+0x278/0x394 kernel/exit.c:432
do_exit+0x1b8/0x1a88 kernel/exit.c:819
do_group_exit+0x194/0x22c kernel/exit.c:1019
get_signal+0x14a0/0x158c kernel/signal.c:2862
do_signal arch/arm64/kernel/signal.c:1076 [inline]
do_notify_resume+0x3ac/0x3474 arch/arm64/kernel/signal.c:1129
prepare_exit_to_user_mode arch/arm64/kernel/entry-common.c:137 [inline]
exit_to_user_mode arch/arm64/kernel/entry-common.c:142 [inline]
el0_svc+0x9c/0x168 arch/arm64/kernel/entry-common.c:638
el0t_64_sync_handler+0x84/0xf0 arch/arm64/kernel/entry-common.c:655
el0t_64_sync+0x18c/0x190 arch/arm64/kernel/entry.S:585
INFO: task syz-executor.4:23916 blocked for more than 143 seconds.
Not tainted 6.1.78-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor.4 state:D stack:0 pid:23916 ppid:4266 flags:0x0000000d
Call trace:
__switch_to+0x320/0x754 arch/arm64/kernel/process.c:553
context_switch kernel/sched/core.c:5245 [inline]
__schedule+0xee4/0x1c98 kernel/sched/core.c:6558
schedule+0xc4/0x170 kernel/sched/core.c:6634
schedule_timeout+0xb8/0x344 kernel/time/timer.c:1911
do_wait_for_common+0x30c/0x468 kernel/sched/completion.c:85
__wait_for_common kernel/sched/completion.c:106 [inline]
wait_for_common kernel/sched/completion.c:117 [inline]
wait_for_completion_state+0x50/0x7c kernel/sched/completion.c:254
coredump_wait fs/coredump.c:405 [inline]
do_coredump+0x7f4/0x2234 fs/coredump.c:562
get_signal+0xfd8/0x158c kernel/signal.c:2848
do_signal arch/arm64/kernel/signal.c:1076 [inline]
do_notify_resume+0x3ac/0x3474 arch/arm64/kernel/signal.c:1129
prepare_exit_to_user_mode arch/arm64/kernel/entry-common.c:137 [inline]
exit_to_user_mode arch/arm64/kernel/entry-common.c:142 [inline]
el0_svc+0x9c/0x168 arch/arm64/kernel/entry-common.c:638
el0t_64_sync_handler+0x84/0xf0 arch/arm64/kernel/entry-common.c:655
el0t_64_sync+0x18c/0x190 arch/arm64/kernel/entry.S:585

Showing all locks held in the system:
1 lock held by rcu_tasks_kthre/12:
#0: ffff800015a14ef0 (rcu_tasks.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x44/0xcf4 kernel/rcu/tasks.h:516
1 lock held by rcu_tasks_trace/13:
#0: ffff800015a156f0 (rcu_tasks_trace.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x44/0xcf4 kernel/rcu/tasks.h:516
1 lock held by khungtaskd/28:
#0: ffff800015a14d20 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0xc/0x44 include/linux/rcupdate.h:317
2 locks held by kworker/1:2/1510:
#0: ffff0000c0021d38 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_one_work+0x664/0x1404 kernel/workqueue.c:2265
#1: ffff8000220a7c20 ((work_completion)(&rew->rew_work)){+.+.}-{0:0}, at: process_one_work+0x6a8/0x1404 kernel/workqueue.c:2267
2 locks held by getty/3985:
#0: ffff0000d638b098 (&tty->ldisc_sem){++++}-{0:0}, at: ldsem_down_read+0x3c/0x4c drivers/tty/tty_ldsem.c:340
#1: ffff80001bcc02f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x414/0x1214 drivers/tty/n_tty.c:2188
1 lock held by syz-executor.2/4257:
#0: ffff800015a1a2f8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:291 [inline]
#0: ffff800015a1a2f8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x3e0/0x768 kernel/rcu/tree_exp.h:949
2 locks held by kworker/1:3/4277:
#0: ffff0000c0020d38 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x664/0x1404 kernel/workqueue.c:2265
#1: ffff80001ded7c20 ((work_completion)(&pwq->unbound_release_work)){+.+.}-{0:0}, at: process_one_work+0x6a8/0x1404 kernel/workqueue.c:2267
2 locks held by kworker/1:4/4306:
#0: ffff0000c0020d38 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x664/0x1404 kernel/workqueue.c:2265
#1: ffff80001e627c20 ((work_completion)(&pwq->unbound_release_work)){+.+.}-{0:0}, at: process_one_work+0x6a8/0x1404 kernel/workqueue.c:2267
2 locks held by kworker/1:8/4547:
#0: ffff0000c0020d38 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x664/0x1404 kernel/workqueue.c:2265
#1: ffff80001f947c20 ((work_completion)(&pwq->unbound_release_work)){+.+.}-{0:0}, at: process_one_work+0x6a8/0x1404 kernel/workqueue.c:2267
2 locks held by kworker/1:9/4548:
#0: ffff0000c0020d38 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x664/0x1404 kernel/workqueue.c:2265
#1: ffff80001f967c20 ((work_completion)(&pwq->unbound_release_work)){+.+.}-{0:0}, at: process_one_work+0x6a8/0x1404 kernel/workqueue.c:2267
2 locks held by kworker/1:10/4549:
#0: ffff0000c0020d38 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x664/0x1404 kernel/workqueue.c:2265
#1: ffff80001f977c20 ((work_completion)(&pwq->unbound_release_work)){+.+.}-{0:0}, at: process_one_work+0x6a8/0x1404 kernel/workqueue.c:2267
2 locks held by kworker/1:12/4551:
#0: ffff0000c0020d38 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x664/0x1404 kernel/workqueue.c:2265
#1: ffff80001f277c20 ((work_completion)(&pwq->unbound_release_work)){+.+.}-{0:0}, at: process_one_work+0x6a8/0x1404 kernel/workqueue.c:2267
2 locks held by kworker/1:13/4552:
#0: ffff0000c0020d38 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x664/0x1404 kernel/workqueue.c:2265
#1: ffff80001f287c20 ((work_completion)(&pwq->unbound_release_work)){+.+.}-{0:0}, at: process_one_work+0x6a8/0x1404 kernel/workqueue.c:2267
2 locks held by kworker/1:15/5114:
#0: ffff0000c0020d38 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x664/0x1404 kernel/workqueue.c:2265
#1: ffff8000208b7c20 ((work_completion)(&pwq->unbound_release_work)){+.+.}-{0:0}, at: process_one_work+0x6a8/0x1404 kernel/workqueue.c:2267
2 locks held by kworker/1:17/7720:
#0: ffff0000c0020d38 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x664/0x1404 kernel/workqueue.c:2265
#1: ffff800029637c20 ((work_completion)(&pwq->unbound_release_work)){+.+.}-{0:0}, at: process_one_work+0x6a8/0x1404 kernel/workqueue.c:2267
3 locks held by kworker/u4:29/20368:
1 lock held by kworker/u4:30/20369:
#0: ffff0001b4390598 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested kernel/sched/core.c:537 [inline]
#0: ffff0001b4390598 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock kernel/sched/sched.h:1354 [inline]
#0: ffff0001b4390598 (&rq->__lock){-.-.}-{2:2}, at: rq_lock kernel/sched/sched.h:1644 [inline]
#0: ffff0001b4390598 (&rq->__lock){-.-.}-{2:2}, at: __schedule+0x2c4/0x1c98 kernel/sched/core.c:6475
2 locks held by kworker/1:7/441:
#0: ffff0000c0020d38 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x664/0x1404 kernel/workqueue.c:2265
#1: ffff800024c57c20 ((work_completion)(&pwq->unbound_release_work)){+.+.}-{0:0}, at: process_one_work+0x6a8/0x1404 kernel/workqueue.c:2267
2 locks held by kworker/1:14/539:
#0: ffff0000c0020d38 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x664/0x1404 kernel/workqueue.c:2265
#1: ffff800025887c20 ((work_completion)(&pwq->unbound_release_work)){+.+.}-{0:0}, at: process_one_work+0x6a8/0x1404 kernel/workqueue.c:2267
2 locks held by kworker/1:21/541:
#0: ffff0000c0020d38 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x664/0x1404 kernel/workqueue.c:2265
#1: ffff800029667c20 ((work_completion)(&pwq->unbound_release_work)){+.+.}-{0:0}, at: process_one_work+0x6a8/0x1404 kernel/workqueue.c:2267
2 locks held by kworker/1:22/14003:
#0: ffff0000c0020d38 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x664/0x1404 kernel/workqueue.c:2265
#1: ffff800022627c20 ((work_completion)(&pwq->unbound_release_work)){+.+.}-{0:0}, at: process_one_work+0x6a8/0x1404 kernel/workqueue.c:2267
2 locks held by kworker/1:23/14004:
#0: ffff0000c0020d38 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x664/0x1404 kernel/workqueue.c:2265
#1: ffff800022667c20 ((work_completion)(&pwq->unbound_release_work)){+.+.}-{0:0}, at: process_one_work+0x6a8/0x1404 kernel/workqueue.c:2267
2 locks held by kworker/1:25/14007:
#0: ffff0000c0020d38 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x664/0x1404 kernel/workqueue.c:2265
#1: ffff800022347c20 ((work_completion)(&pwq->unbound_release_work)){+.+.}-{0:0}, at: process_one_work+0x6a8/0x1404 kernel/workqueue.c:2267
1 lock held by udevd/24284:
#0: ffff0000c049ebd8 (mapping.invalidate_lock#2){.+.+}-{3:3}, at: filemap_invalidate_lock_shared include/linux/fs.h:811 [inline]
#0: ffff0000c049ebd8 (mapping.invalidate_lock#2){.+.+}-{3:3}, at: page_cache_ra_unbounded+0xc8/0x58c mm/readahead.c:226
1 lock held by udevd/24346:
#0: ffff0000c049cad8 (mapping.invalidate_lock#2){.+.+}-{3:3}, at: filemap_invalidate_lock_shared include/linux/fs.h:811 [inline]
#0: ffff0000c049cad8 (mapping.invalidate_lock#2){.+.+}-{3:3}, at: page_cache_ra_unbounded+0xc8/0x58c mm/readahead.c:226
2 locks held by kworker/1:26/26540:
#0: ffff0000c0020d38 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x664/0x1404 kernel/workqueue.c:2265
#1: ffff80002d117c20 ((work_completion)(&pwq->unbound_release_work)){+.+.}-{0:0}, at: process_one_work+0x6a8/0x1404 kernel/workqueue.c:2267
1 lock held by syz-executor.4/29642:
#0: ffff800015a1a2f8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:323 [inline]
#0: ffff800015a1a2f8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x394/0x768 kernel/rcu/tree_exp.h:949
2 locks held by syz-executor.1/29665:

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