INFO: task syz.1.2689:16093 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.1.2689 state:D stack:22352 pid:16093 ppid:4277 flags:0x00004006
Call Trace:
context_switch kernel/sched/core.c:5246 [inline]
__schedule+0x107f/0x4030 kernel/sched/core.c:6563
schedule+0xb9/0x180 kernel/sched/core.c:6639
perf_pending_task_sync kernel/events/core.c:5041 [inline]
_free_event+0x176/0x1050 kernel/events/core.c:5047
put_event kernel/events/core.c:5172 [inline]
perf_event_release_kernel+0x7c4/0x850 kernel/events/core.c:5297
perf_release+0x37/0x40 kernel/events/core.c:5307
__fput+0x20a/0x8b0 fs/file_table.c:320
task_work_run+0x1d0/0x260 kernel/task_work.c:203
get_signal+0x118d/0x1340 kernel/signal.c:2657
arch_do_signal_or_restart+0xc4/0x1310 arch/x86/kernel/signal.c:871
exit_to_user_mode_loop+0x70/0x110 kernel/entry/common.c:174
exit_to_user_mode_prepare+0xee/0x180 kernel/entry/common.c:210
__syscall_exit_to_user_mode_work kernel/entry/common.c:292 [inline]
syscall_exit_to_user_mode+0x16/0x40 kernel/entry/common.c:303
do_syscall_64+0x58/0xa0 arch/x86/entry/common.c:82
entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f4860d9e159
RSP: 002b:00007f4861c2afd8 EFLAGS: 00000206 ORIG_RAX: 0000000000000038
RAX: fffffffffffffffc RBX: 00007f4861025fa0 RCX: 00007f4860d9e159
RDX: 0000200000000500 RSI: 0000200000000380 RDI: 0000000040008000
RBP: 00007f4860e3503b R08: 0000200000000580 R09: 0000200000000580
R10: 0000200000000540 R11: 0000000000000206 R12: 0000000000000000
R13: 00007f4861026038 R14: 00007f4861025fa0 R15: 00007ffd5e578468
Showing all locks held in the system:
1 lock held by rcu_tasks_kthre/12:
#0: ffffffff8cb2e5b0 (rcu_tasks.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x33/0xef0 kernel/rcu/tasks.h:517
1 lock held by rcu_tasks_trace/13:
#0: ffffffff8cb2edd0 (rcu_tasks_trace.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x33/0xef0 kernel/rcu/tasks.h:517
1 lock held by khungtaskd/28:
#0: ffffffff8cb2dc20 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:350 [inline]
#0: ffffffff8cb2dc20 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:791 [inline]
#0: ffffffff8cb2dc20 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x51/0x290 kernel/locking/lockdep.c:6527
1 lock held by udevd/3638:
2 locks held by getty/4025:
#0: ffff88802fd26098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:244
#1: ffffc9000327b2f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x41e/0x1360 drivers/tty/n_tty.c:2198
2 locks held by kworker/u4:54/14968:
2 locks held by syz.0.3355/19015:
2 locks held by syz.0.3355/19025:
2 locks held by syz.0.3387/19147:
1 lock held by syz.0.3391/19169:
=============================================
NMI backtrace for cpu 0
CPU: 0 PID: 28 Comm: khungtaskd Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
Call Trace:
dump_stack_lvl+0x188/0x24e lib/dump_stack.c:106
nmi_cpu_backtrace+0x3e6/0x460 lib/nmi_backtrace.c:111
nmi_trigger_cpumask_backtrace+0x1d4/0x450 lib/nmi_backtrace.c:62
trigger_all_cpu_backtrace include/linux/nmi.h:148 [inline]
check_hung_uninterruptible_tasks kernel/hung_task.c:220 [inline]
watchdog+0xf0e/0xf50 kernel/hung_task.c:377
kthread+0x29d/0x330 kernel/kthread.c:376
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 6148 Comm: kworker/u4:13 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
Workqueue: events_unbound nsim_dev_trap_report_work
RIP: 0010:ct_dynticks_nmi_nesting include/linux/context_tracking_state.h:92 [inline]
RIP: 0010:ct_nmi_enter+0xc1/0x170 kernel/context_tracking.c:299
Code: bf 01 00 00 00 eb 0f 41 bf 02 00 00 00 a9 00 00 f0 00 75 02 66 90 48 c7 c7 80 e4 94 8a e8 f7 08 00 00 65 48 8b 05 07 03 d2 75 <48> c7 c7 80 e4 94 8a e8 e3 08 00 00 65 48 8b 05 f3 02 d2 75 e8 b6
RSP: 0018:ffffc90004a17900 EFLAGS: 00000086
RAX: 4000000000000000 RBX: 0000000000000001 RCX: 826f0c0dc4b7a000
RDX: 0000000000000000 RSI: ffffffff8a94e480 RDI: ffffffff8adf6420
RBP: ffffc90004a179d8 R08: ffffffff8e2116af R09: 1ffffffff1c422d5
R10: dffffc0000000000 R11: fffffbfff1c422d6 R12: dffffc0000000000
R13: 0000000000000001 R14: ffff8880b8f357c0 R15: 0000000000000002
FS: 0000000000000000(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fc6107ef2f8 CR3: 000000007e03b000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600
Call Trace:
ct_irq_enter_irqson+0xaf/0x170 kernel/context_tracking.c:407
trace_irq_disable_rcuidle+0x9f/0x140 include/trace/events/preemptirq.h:36
___slab_alloc+0x1e3/0x1240 mm/slub.c:3055
__slab_alloc mm/slub.c:3240 [inline]
slab_alloc_node mm/slub.c:3325 [inline]
kmem_cache_alloc_node+0x134/0x310 mm/slub.c:3404
__alloc_skb+0xf9/0x7d0 net/core/skbuff.c:505
alloc_skb include/linux/skbuff.h:1303 [inline]
nsim_dev_trap_skb_build drivers/net/netdevsim/dev.c:748 [inline]
nsim_dev_trap_report drivers/net/netdevsim/dev.c:805 [inline]
nsim_dev_trap_report_work+0x24f/0xa80 drivers/net/netdevsim/dev.c:851
process_one_work+0x8ab/0x1160 kernel/workqueue.c:2292
worker_thread+0xaf5/0x12a0 kernel/workqueue.c:2439
kthread+0x29d/0x330 kernel/kthread.c:376
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295