INFO: task syz.1.769:7381 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.1.769 state:D stack:23216 pid:7381 ppid:4276 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:2661
arch_do_signal_or_restart+0xc4/0x1310 arch/x86/kernel/signal.c:871
exit_to_user_mode_loop+0x70/0x110 kernel/entry/common.c:177
exit_to_user_mode_prepare+0xee/0x180 kernel/entry/common.c:213
__syscall_exit_to_user_mode_work kernel/entry/common.c:295 [inline]
syscall_exit_to_user_mode+0x16/0x40 kernel/entry/common.c:306
do_syscall_64+0x58/0xa0 arch/x86/entry/common.c:82
entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f9c98b9f559
RSP: 002b:00007f9c99abbfd8 EFLAGS: 00000202 ORIG_RAX: 0000000000000038
RAX: fffffffffffffffc RBX: 00007f9c98e25fa0 RCX: 00007f9c98b9f559
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 00000000c0126080
RBP: 00007f9c98c36b20 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000000
R13: 00007f9c98e26038 R14: 00007f9c98e25fa0 R15: 00007fff46321748
Showing all locks held in the system:
1 lock held by rcu_tasks_kthre/12:
#0: ffffffff8db2e230 (rcu_tasks.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x33/0xef0 kernel/rcu/tasks.h:517
1 lock held by khungtaskd/27:
#0: ffffffff8db2d8a0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:350 [inline]
#0: ffffffff8db2d8a0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:791 [inline]
#0: ffffffff8db2d8a0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x51/0x290 kernel/locking/lockdep.c:6669
3 locks held by kworker/u4:3/51:
#0: ffff888018479138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work+0x7b4/0x1160 kernel/workqueue.c:2267
#1: ffffc90000bc7d00 ((work_completion)(&map->work)){+.+.}-{0:0}, at: process_one_work+0x7b4/0x1160 kernel/workqueue.c:2267
#2: ffffffff8db33578 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:291 [inline]
#2: ffffffff8db33578 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x2ec/0x890 kernel/rcu/tree_exp.h:962
2 locks held by getty/4035:
#0: ffff88814d5c3098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:244
#1: ffffc9000327e2f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x41e/0x1360 drivers/tty/n_tty.c:2198
2 locks held by kworker/u4:13/7992:
#0: ffff8880b8c3acd8 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x25/0x130 kernel/sched/core.c:538
#1: ffffffff8db2d8a0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:350 [inline]
#1: ffffffff8db2d8a0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:791 [inline]
#1: ffffffff8db2d8a0 (rcu_read_lock){....}-{1:2}, at: do_perf_sw_event kernel/events/core.c:9746 [inline]
#1: ffffffff8db2d8a0 (rcu_read_lock){....}-{1:2}, at: ___perf_sw_event+0x184/0x6d0 kernel/events/core.c:9784
2 locks held by kworker/0:8/8765:
#0: ffff888018472138 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_one_work+0x7b4/0x1160 kernel/workqueue.c:2267
#1: ffffc90004687d00 ((work_completion)(&rew->rew_work)){+.+.}-{0:0}, at: process_one_work+0x7b4/0x1160 kernel/workqueue.c:2267
2 locks held by syz.4.1606/10710:
#0: ffffffff8ed69250 (pernet_ops_rwsem){++++}-{3:3}, at: copy_net_ns+0x324/0x5b0 net/core/net_namespace.c:504
#1: ffffffff8ed760e8 (rtnl_mutex){+.+.}-{3:3}, at: setup_net+0x7fd/0xbd0 net/core/net_namespace.c:358
1 lock held by syz.3.1610/10721:
#0: ffffffff8ed760e8 (rtnl_mutex){+.+.}-{3:3}, at: tun_detach drivers/net/tun.c:698 [inline]
#0: ffffffff8ed760e8 (rtnl_mutex){+.+.}-{3:3}, at: tun_chr_close+0x3d/0x1b0 drivers/net/tun.c:3506
1 lock held by syz.2.1611/10726:
#0: ffffffff8db82b68 (event_mutex){+.+.}-{3:3}, at: perf_trace_destroy+0x2a/0x140 kernel/trace/trace_event_perf.c:239
2 locks held by syz.0.1612/10727:
#0: ffffffff8ed760e8 (rtnl_mutex){+.+.}-{3:3}, at: tun_detach drivers/net/tun.c:698 [inline]
#0: ffffffff8ed760e8 (rtnl_mutex){+.+.}-{3:3}, at: tun_chr_close+0x3d/0x1b0 drivers/net/tun.c:3506
#1: ffffffff8db33578 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:323 [inline]
#1: ffffffff8db33578 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x3c0/0x890 kernel/rcu/tree_exp.h:962
=============================================
NMI backtrace for cpu 1
CPU: 1 PID: 27 Comm: khungtaskd Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/07/2026
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 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 7992 Comm: kworker/u4:13 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/07/2026
Workqueue: events_unbound nsim_dev_trap_report_work
RIP: 0010:__this_cpu_preempt_check+0x0/0x10 lib/smp_processor_id.c:65
Code: 48 89 da e8 82 a3 f4 ff 48 8b 74 24 30 48 c7 c7 60 72 ff 8a e8 71 a3 f4 ff e8 9a 8b ff ff eb a8 e8 c5 e9 ff ff 0f 1f 44 00 00 <48> 89 fe 48 c7 c7 e0 71 ff 8a e9 e1 fe ff ff 00 eb 1e 0f 1f 00 48
RSP: 0018:ffffc90004f877b8 EFLAGS: 00000046
RAX: 0000000000000004 RBX: ffff888024693c00 RCX: ffffffff8164beb4
RDX: dffffc0000000000 RSI: ffff8880246946d8 RDI: ffffffff8aac2b20
RBP: ffffc90004f87868 R08: ffffffff91b70337 R09: 1ffffffff236e066
R10: dffffc0000000000 R11: fffffbfff236e067 R12: ffff8880246947a0
R13: 0000000000000004 R14: 1ffff110048d28db R15: ffff888024694780
FS: 0000000000000000(0000) GS:ffff8880b8c00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007ffdd2c07d90 CR3: 0000000028be1000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600
Call Trace:
lockdep_recursion_finish kernel/locking/lockdep.c:467 [inline]
lockdep_hardirqs_on_prepare+0x448/0x7c0 kernel/locking/lockdep.c:4388
trace_hardirqs_on+0x34/0x40 kernel/trace/trace_preemptirq.c:49
crng_make_state+0x4ee/0xb00 drivers/char/random.c:353
_get_random_bytes+0xfc/0x250 drivers/char/random.c:366
nsim_dev_trap_skb_build drivers/net/netdevsim/dev.c:776 [inline]
nsim_dev_trap_report drivers/net/netdevsim/dev.c:805 [inline]
nsim_dev_trap_report_work+0x608/0xa80 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