INFO: task syz.0.16:4919 blocked for more than 143 seconds.
Not tainted 6.6.0-rc2-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.0.16 state:D stack:27840 pid:4919 ppid:3103 flags:0x00004000
Call Trace:
context_switch kernel/sched/core.c:5382 [inline]
__schedule+0x14df/0x2370 kernel/sched/core.c:6695
schedule+0xe8/0x1f0 kernel/sched/core.c:6771
schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6830
__mutex_lock_common kernel/locking/mutex.c:679 [inline]
__mutex_lock+0x68b/0xc90 kernel/locking/mutex.c:747
io_uring_del_tctx_node+0xe0/0x280 io_uring/tctx.c:169
io_uring_clean_tctx+0xb6/0x140 io_uring/tctx.c:185
io_uring_cancel_generic+0x595/0x5e0 io_uring/io_uring.c:3426
io_uring_files_cancel include/linux/io_uring.h:78 [inline]
do_exit+0x445/0x1e40 kernel/exit.c:831
do_group_exit+0x1b0/0x280 kernel/exit.c:1026
get_signal+0xe3e/0xf10 kernel/signal.c:2892
arch_do_signal_or_restart+0x80/0x590 arch/x86/kernel/signal.c:309
exit_to_user_mode_loop+0x70/0xf0 kernel/entry/common.c:168
exit_to_user_mode_prepare+0xac/0x130 kernel/entry/common.c:204
__syscall_exit_to_user_mode_work kernel/entry/common.c:285 [inline]
syscall_exit_to_user_mode+0x1b/0x60 kernel/entry/common.c:296
do_syscall_64+0x6a/0xb0 arch/x86/entry/common.c:86
entry_SYSCALL_64_after_hwframe+0x6f/0xd9
RIP: 0033:0x7f293538e969
RSP: 002b:00007f293612c0e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca
RAX: fffffffffffffe00 RBX: 00007f29355b5fa8 RCX: 00007f293538e969
RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007f29355b5fa8
RBP: 00007f29355b5fa0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007f29355b5fac
R13: 0000000000000000 R14: 00007ffc43dab1a0 R15: 00007ffc43dab288
Showing all locks held in the system:
2 locks held by kworker/u4:0/11:
#0: ffff888100079938 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2605 [inline]
#0: ffff888100079938 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0x7e3/0xfb0 kernel/workqueue.c:2703
#1: ffffc900000bfd00 ((work_completion)(&sub_info->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2605 [inline]
#1: ffffc900000bfd00 ((work_completion)(&sub_info->work)){+.+.}-{0:0}, at: process_scheduled_works+0x7e3/0xfb0 kernel/workqueue.c:2703
1 lock held by khungtaskd/27:
#0: ffffffff864ce200 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:303 [inline]
#0: ffffffff864ce200 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:749 [inline]
#0: ffffffff864ce200 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x55/0x290 kernel/locking/lockdep.c:6613
2 locks held by kworker/u4:5/418:
#0: ffff888100079938 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2605 [inline]
#0: ffff888100079938 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0x7e3/0xfb0 kernel/workqueue.c:2703
#1: ffffc90001e6fd00 ((work_completion)(&sub_info->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2605 [inline]
#1: ffffc90001e6fd00 ((work_completion)(&sub_info->work)){+.+.}-{0:0}, at: process_scheduled_works+0x7e3/0xfb0 kernel/workqueue.c:2703
2 locks held by kworker/u4:7/687:
#0: ffff888100079938 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2605 [inline]
#0: ffff888100079938 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0x7e3/0xfb0 kernel/workqueue.c:2703
#1: ffffc90002817d00 ((work_completion)(&sub_info->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2605 [inline]
#1: ffffc90002817d00 ((work_completion)(&sub_info->work)){+.+.}-{0:0}, at: process_scheduled_works+0x7e3/0xfb0 kernel/workqueue.c:2703
2 locks held by kworker/u4:12/916:
2 locks held by kworker/u4:17/1243:
#0: ffff888100079938 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2605 [inline]
#0: ffff888100079938 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0x7e3/0xfb0 kernel/workqueue.c:2703
#1: ffffc900043c7d00 ((work_completion)(&sub_info->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2605 [inline]
#1: ffffc900043c7d00 ((work_completion)(&sub_info->work)){+.+.}-{0:0}, at: process_scheduled_works+0x7e3/0xfb0 kernel/workqueue.c:2703
2 locks held by getty/1603:
#0: ffff88810bf560a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x20/0x60 drivers/tty/tty_ldisc.c:243
#1: ffffc900000532f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x36b/0xf30 drivers/tty/n_tty.c:2206
1 lock held by syz.4.20/4906:
1 lock held by syz.7.18/4914:
1 lock held by syz.0.16/4919:
#0: ffff88817ae120a8 (&ctx->uring_lock){+.+.}-{4:4}, at: io_uring_del_tctx_node+0xe0/0x280 io_uring/tctx.c:169
1 lock held by syz.0.16/4921:
1 lock held by syz.3.19/4930:
1 lock held by syz.8.27/5336:
1 lock held by syz.2.23/7114:
1 lock held by syz.9.29/7117:
#0: ffff88817e93e0a8 (&ctx->uring_lock){+.+.}-{4:4}, at: io_uring_del_tctx_node+0xe0/0x280 io_uring/tctx.c:169
1 lock held by syz.9.29/7119:
1 lock held by syz.1.24/7126:
1 lock held by syz.5.25/7130:
#0: ffff88817e3dc0a8 (&ctx->uring_lock){+.+.}-{4:4}, at: io_uring_del_tctx_node+0xe0/0x280 io_uring/tctx.c:169
1 lock held by syz.5.25/7131:
1 lock held by syz.6.42/7370:
#0: ffff88815b0160a8 (&ctx->uring_lock){+.+.}-{4:4}, at: io_uring_del_tctx_node+0xe0/0x280 io_uring/tctx.c:169
1 lock held by syz.6.42/7371:
1 lock held by modprobe/8704:
#0: ffff8881f6039cd8 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested kernel/sched/core.c:558 [inline]
#0: ffff8881f6039cd8 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock kernel/sched/sched.h:1372 [inline]
#0: ffff8881f6039cd8 (&rq->__lock){-.-.}-{2:2}, at: rq_lock kernel/sched/sched.h:1681 [inline]
#0: ffff8881f6039cd8 (&rq->__lock){-.-.}-{2:2}, at: __schedule+0x2df/0x2370 kernel/sched/core.c:6612
1 lock held by modprobe/8706:
=============================================
NMI backtrace for cpu 1
CPU: 1 PID: 27 Comm: khungtaskd Not tainted 6.6.0-rc2-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
Call Trace:
dump_stack_lvl+0xd6/0x150 lib/dump_stack.c:106
nmi_cpu_backtrace+0x209/0x2b0 lib/nmi_backtrace.c:113
nmi_trigger_cpumask_backtrace+0x102/0x210 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+0xb04/0xb40 kernel/hung_task.c:379
kthread+0x27d/0x300 kernel/kthread.c:388
ret_from_fork+0x32/0x70 arch/x86/kernel/process.c:147
ret_from_fork_asm+0x1b/0x30 arch/x86/entry/entry_64.S:304
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 970 Comm: kworker/u4:13 Not tainted 6.6.0-rc2-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
Workqueue: events_unbound toggle_allocation_gate
RIP: 0010:__raw_callee_save___pv_queued_spin_unlock+0x10/0x1a
Code: 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 52 b8 01 00 00 00 31 d2 f0 0f b0 17 <3c> 01 75 06 5a c3 cc cc cc cc 56 0f b6 f0 e8 9d ff ff ff 5e 5a c3
RSP: 0000:ffffc900035d7838 EFLAGS: 00000046
RAX: 0000000000000001 RBX: ffffffff8f3f9de8 RCX: 0000000000000000
RDX: 0000000000000000 RSI: 0000000000000004 RDI: ffffffff8f3f9de8
RBP: 1ffffffff1e7f3be R08: ffffffff8f3f9deb R09: 1ffffffff1e7f3bd
R10: dffffc0000000000 R11: fffffbfff1e7f3be R12: dffffc0000000000
R13: 1ffffffff1e7f3bf R14: ffffffff8f3f9df8 R15: ffffffff8f3f9df0
FS: 0000000000000000(0000) GS:ffff8881f6000000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f5b5b458f50 CR3: 00000000062e4000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
pv_queued_spin_unlock arch/x86/include/asm/paravirt.h:591 [inline]
queued_spin_unlock arch/x86/include/asm/qspinlock.h:57 [inline]
do_raw_spin_unlock+0x121/0x230 kernel/locking/spinlock_debug.c:141
__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:150 [inline]
_raw_spin_unlock_irqrestore+0x6b/0xf0 kernel/locking/spinlock.c:194
debug_object_assert_init+0x1ed/0x2d0 lib/debugobjects.c:930
debug_timer_assert_init kernel/time/timer.c:792 [inline]
debug_assert_init kernel/time/timer.c:837 [inline]
__mod_timer+0x3f/0xa70 kernel/time/timer.c:1020
queue_delayed_work_on+0xc7/0x140 kernel/workqueue.c:1986
queue_delayed_work include/linux/workqueue.h:569 [inline]
toggle_allocation_gate+0x17d/0x1c0 mm/kfence/core.c:837
process_one_work kernel/workqueue.c:2630 [inline]
process_scheduled_works+0x87f/0xfb0 kernel/workqueue.c:2703
worker_thread+0x883/0xd20 kernel/workqueue.c:2784
kthread+0x27d/0x300 kernel/kthread.c:388
ret_from_fork+0x32/0x70 arch/x86/kernel/process.c:147
ret_from_fork_asm+0x1b/0x30 arch/x86/entry/entry_64.S:304