INFO: task syz.7.8154:29671 blocked for more than 143 seconds.
Not tainted 6.6.93-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.7.8154 state:D stack:27016 pid:29671 ppid:23393 flags:0x00004000
Call Trace:
<TASK>
context_switch kernel/sched/core.c:5381 [inline]
__schedule+0x14e2/0x4580 kernel/sched/core.c:6700
schedule+0xbd/0x170 kernel/sched/core.c:6774
schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:6833
__mutex_lock_common kernel/locking/mutex.c:679 [inline]
__mutex_lock+0x6b7/0xcc0 kernel/locking/mutex.c:747
__pipe_lock fs/pipe.c:103 [inline]
pipe_release+0x51/0x330 fs/pipe.c:725
__fput+0x234/0x970 fs/file_table.c:384
task_work_run+0x1ce/0x250 kernel/task_work.c:239
resume_user_mode_work include/linux/resume_user_mode.h:49 [inline]
exit_to_user_mode_loop+0xe6/0x110 kernel/entry/common.c:177
exit_to_user_mode_prepare+0xb1/0x140 kernel/entry/common.c:210
__syscall_exit_to_user_mode_work kernel/entry/common.c:291 [inline]
syscall_exit_to_user_mode+0x1a/0x50 kernel/entry/common.c:302
do_syscall_64+0x61/0xb0 arch/x86/entry/common.c:87
entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7fea9ab8e929
RSP: 002b:00007ffc8b87ec48 EFLAGS: 00000246 ORIG_RAX: 00000000000001b4
RAX: 0000000000000000 RBX: 00007fea9adb7ba0 RCX: 00007fea9ab8e929
RDX: 0000000000000000 RSI: 000000000000001e RDI: 0000000000000003
RBP: 00007fea9adb7ba0 R08: 0000000000000384 R09: 000000088b87ef3f
R10: 00007fea9adb7ac0 R11: 0000000000000246 R12: 000000000012c332
R13: 00007ffc8b87ed40 R14: ffffffffffffffff R15: 00007ffc8b87ed60
</TASK>
Showing all locks held in the system:
4 locks held by kworker/u4:0/11:
1 lock held by khungtaskd/29:
#0: ffffffff8cd2f760 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:334 [inline]
#0: ffffffff8cd2f760 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:786 [inline]
#0: ffffffff8cd2f760 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x55/0x290 kernel/locking/lockdep.c:6633
2 locks held by getty/5533:
#0: ffff88802d2670a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
#1: ffffc9000326b2f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x425/0x1380 drivers/tty/n_tty.c:2217
1 lock held by syz-executor/26926:
1 lock held by syz.7.8154/29671:
#0: ffff88804c820c68 (&pipe->mutex/1){+.+.}-{3:3}, at: __pipe_lock fs/pipe.c:103 [inline]
#0: ffff88804c820c68 (&pipe->mutex/1){+.+.}-{3:3}, at: pipe_release+0x51/0x330 fs/pipe.c:725
1 lock held by syz.7.8154/29672:
#0: ffff88804c820c68 (&pipe->mutex/1){+.+.}-{3:3}, at: splice_file_to_pipe+0x2a/0x110 fs/splice.c:1230
=============================================
NMI backtrace for cpu 0
CPU: 0 PID: 29 Comm: khungtaskd Not tainted 6.6.93-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
Call Trace:
<TASK>
dump_stack_lvl+0x16c/0x230 lib/dump_stack.c:106
nmi_cpu_backtrace+0x39b/0x3d0 lib/nmi_backtrace.c:113
nmi_trigger_cpumask_backtrace+0x17a/0x2f0 lib/nmi_backtrace.c:62
trigger_all_cpu_backtrace include/linux/nmi.h:160 [inline]
check_hung_uninterruptible_tasks kernel/hung_task.c:222 [inline]
watchdog+0xf41/0xf80 kernel/hung_task.c:379
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>
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 29694 Comm: udevd Not tainted 6.6.93-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
RIP: 0010:check_kcov_mode kernel/kcov.c:193 [inline]
RIP: 0010:write_comp_data kernel/kcov.c:245 [inline]
RIP: 0010:__sanitizer_cov_trace_const_cmp1+0x36/0x90 kernel/kcov.c:299
Code: 80 20 7e 7e 65 8b 0d 81 20 7e 7e 81 e1 00 01 ff 00 74 11 81 f9 00 01 00 00 75 5b 83 ba 1c 16 00 00 00 74 52 8b 8a f8 15 00 00 <83> f9 03 75 47 48 8b 8a 00 16 00 00 44 8b 8a fc 15 00 00 49 c1 e1
RSP: 0018:ffffc900054f7bd8 EFLAGS: 00000246
RAX: ffffffff82013e98 RBX: ffff8880254a6780 RCX: 0000000000000000
RDX: ffff88807d2bbc00 RSI: 0000000000000001 RDI: 0000000000000002
RBP: ffffc900054f7e30 R08: ffff8880254a67df R09: 1ffff11004a94cfb
R10: dffffc0000000000 R11: ffffed1004a94cfc R12: ffff88801ef19f18
R13: 0000000000000001 R14: ffff8880254a67d8 R15: dffffc0000000001
FS: 00007f015ef88880(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007ffff01f1780 CR3: 000000001bfe4000 CR4: 00000000003506e0
Call Trace:
<TASK>
arch_atomic64_try_cmpxchg arch/x86/include/asm/atomic64_64.h:109 [inline]
raw_atomic64_try_cmpxchg include/linux/atomic/atomic-arch-fallback.h:4224 [inline]
raw_atomic64_fetch_add_unless include/linux/atomic/atomic-arch-fallback.h:4521 [inline]
raw_atomic64_add_unless include/linux/atomic/atomic-arch-fallback.h:4545 [inline]
raw_atomic64_inc_not_zero include/linux/atomic/atomic-arch-fallback.h:4565 [inline]
raw_atomic_long_inc_not_zero include/linux/atomic/atomic-long.h:1731 [inline]
atomic_long_inc_not_zero include/linux/atomic/atomic-instrumented.h:4654 [inline]
epi_fget fs/eventpoll.c:903 [inline]
ep_item_poll fs/eventpoll.c:916 [inline]
ep_send_events fs/eventpoll.c:1772 [inline]
ep_poll fs/eventpoll.c:1905 [inline]
do_epoll_wait+0xb78/0x1b70 fs/eventpoll.c:2359
__do_sys_epoll_wait fs/eventpoll.c:2371 [inline]
__se_sys_epoll_wait fs/eventpoll.c:2366 [inline]
__x64_sys_epoll_wait+0x1bf/0x210 fs/eventpoll.c:2366
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: 0033:0x7f015e8a7407
Code: 48 89 fa 4c 89 df e8 38 aa 00 00 8b 93 08 03 00 00 59 5e 48 83 f8 fc 74 1a 5b c3 0f 1f 84 00 00 00 00 00 48 8b 44 24 10 0f 05 <5b> c3 0f 1f 80 00 00 00 00 83 e2 39 83 fa 08 75 de e8 23 ff ff ff
RSP: 002b:00007ffcd3692330 EFLAGS: 00000202 ORIG_RAX: 00000000000000e8
RAX: ffffffffffffffda RBX: 00007f015ef88880 RCX: 00007f015e8a7407
RDX: 0000000000000004 RSI: 00007ffcd36923c0 RDI: 0000000000000004
RBP: 0000557b51dfc910 R08: 0000000000000000 R09: 0000000000000000
R10: ffffffffffffffff R11: 0000000000000202 R12: 00007ffcd36923cc
R13: 00007ffcd36923c0 R14: 0000000000000000 R15: 0000000000000001
</TASK>