INFO: task syz.3.3196:16747 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.3.3196 state:D stack:23728 pid:16747 ppid: 16109 flags:0x00004006
Call Trace:
context_switch kernel/sched/core.c:5049 [inline]
__schedule+0x11c3/0x4350 kernel/sched/core.c:6395
schedule+0x11b/0x1e0 kernel/sched/core.c:6478
perf_pending_task_sync+0x13c/0x1c0 kernel/events/core.c:5137
_free_event+0x34/0xe30 kernel/events/core.c:5143
put_event kernel/events/core.c:5268 [inline]
perf_event_release_kernel+0x7c4/0x850 kernel/events/core.c:5393
perf_release+0x37/0x40 kernel/events/core.c:5403
__fput+0x212/0x8c0 fs/file_table.c:311
task_work_run+0x125/0x1a0 kernel/task_work.c:188
get_signal+0x123e/0x12e0 kernel/signal.c:2689
arch_do_signal_or_restart+0xe6/0x12a0 arch/x86/kernel/signal.c:867
handle_signal_work kernel/entry/common.c:157 [inline]
exit_to_user_mode_loop+0x9e/0x130 kernel/entry/common.c:181
exit_to_user_mode_prepare+0xee/0x180 kernel/entry/common.c:217
__syscall_exit_to_user_mode_work kernel/entry/common.c:299 [inline]
syscall_exit_to_user_mode+0x16/0x40 kernel/entry/common.c:310
do_syscall_64+0x58/0xa0 arch/x86/entry/common.c:86
entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7f60f4f5cb19
RSP: 002b:00007f60f3191fd8 EFLAGS: 00000206 ORIG_RAX: 0000000000000038
RAX: fffffffffffffff4 RBX: 00007f60f51e3090 RCX: 00007f60f4f5cb19
RDX: 0000200000000640 RSI: 0000200000000580 RDI: 0000000042040000
RBP: 00007f60f4ff4b70 R08: 0000200000000780 R09: 0000200000000780
R10: 0000200000000700 R11: 0000000000000206 R12: 0000000000000000
R13: 00007f60f51e3128 R14: 00007f60f51e3090 R15: 00007ffd152b9698
Showing all locks held in the system:
1 lock held by khungtaskd/27:
#0: ffffffff8d11efa0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x0/0x30
3 locks held by kworker/u4:2/155:
2 locks held by getty/3949:
#0: ffff88802cb59098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:252
#1: ffffc90002d032e8 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x594/0x1a50 drivers/tty/n_tty.c:2158
3 locks held by kworker/u4:7/5367:
2 locks held by kworker/0:62/10443:
#0: ffff888017872138 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_one_work+0x75c/0xff0 kernel/workqueue.c:-1
#1: ffffc9000435fd00 ((work_completion)(&rew.rew_work)){+.+.}-{0:0}, at: process_one_work+0x79e/0xff0 kernel/workqueue.c:2285
3 locks held by kworker/0:64/10445:
#0: ffff888017870938 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x75c/0xff0 kernel/workqueue.c:-1
#1: ffffc9000437fd00 ((work_completion)(&map->work)){+.+.}-{0:0}, at: process_one_work+0x79e/0xff0 kernel/workqueue.c:2285
#2: ffffffff8d123a28 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:290 [inline]
#2: ffffffff8d123a28 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x2d1/0x750 kernel/rcu/tree_exp.h:845
2 locks held by syz.9.3950/19717:
#0: ffffffff8d16c808 (event_mutex){+.+.}-{3:3}, at: perf_trace_destroy+0x2a/0x140 kernel/trace/trace_event_perf.c:239
#1: ffffffff8d123a28 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:322 [inline]
#1: ffffffff8d123a28 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x3a5/0x750 kernel/rcu/tree_exp.h:845
1 lock held by dhcpcd/19741:
#0: ffff88807c2e8120 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1744 [inline]
#0: ffff88807c2e8120 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: packet_do_bind+0x32/0xd60 net/packet/af_packet.c:3250
2 locks held by sed/19747:
=============================================
NMI backtrace for cpu 0
CPU: 0 PID: 27 Comm: khungtaskd Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/15/2026
Call Trace:
dump_stack_lvl+0x188/0x250 lib/dump_stack.c:106
nmi_cpu_backtrace+0x3a2/0x3d0 lib/nmi_backtrace.c:111
nmi_trigger_cpumask_backtrace+0x163/0x280 lib/nmi_backtrace.c:62
trigger_all_cpu_backtrace include/linux/nmi.h:148 [inline]
check_hung_uninterruptible_tasks kernel/hung_task.c:212 [inline]
watchdog+0xe1b/0xe60 kernel/hung_task.c:369
kthread+0x42e/0x520 kernel/kthread.c:334
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 15 Comm: rcu_preempt Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/15/2026
RIP: 0010:pv_queued_spin_unlock arch/x86/include/asm/paravirt.h:590 [inline]
RIP: 0010:queued_spin_unlock arch/x86/include/asm/qspinlock.h:56 [inline]
RIP: 0010:do_raw_spin_unlock+0x10f/0x230 kernel/locking/spinlock_debug.c:141
Code: ff ff ff ff 48 c7 c0 18 30 f9 8c 48 c1 e8 03 42 80 3c 20 00 74 0c 48 c7 c7 18 30 f9 8c e8 19 1c 60 00 48 83 3d 69 d6 9a 0b 00 <0f> 84 10 01 00 00 48 89 df e8 83 dd ff ff 66 90 5b 41 5c 41 5d 41
RSP: 0018:ffffc90000d47968 EFLAGS: 00000082
RAX: 1ffffffff19f2603 RBX: ffffffff9732f380 RCX: 0000000000000001
RDX: 0000000000000000 RSI: 0000000000000004 RDI: ffffffff9732f380
RBP: 1ffffffff2e65e71 R08: ffffffff9732f383 R09: 1ffffffff2e65e70
R10: dffffc0000000000 R11: fffffbfff2e65e71 R12: dffffc0000000000
R13: 1ffffffff2e65e72 R14: ffffffff9732f390 R15: ffffffff9732f388
FS: 0000000000000000(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fbc8f4352f8 CR3: 0000000025c16000 CR4: 00000000003506e0
DR0: 0000200000002640 DR1: 0000200000000300 DR2: 00002000000000c0
DR3: 00002000000000c0 DR6: 00000000ffff0ff0 DR7: 0000000000000600
Call Trace:
__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:159 [inline]
_raw_spin_unlock_irqrestore+0x75/0x120 kernel/locking/spinlock.c:194
__debug_object_init+0x253/0xc80 lib/debugobjects.c:633
init_timer_on_stack_key kernel/time/timer.c:752 [inline]
schedule_timeout+0x12d/0x2d0 kernel/time/timer.c:2115
rcu_gp_fqs_loop+0x2be/0x11f0 kernel/rcu/tree.c:1972
rcu_gp_kthread+0x9a/0x370 kernel/rcu/tree.c:2145
kthread+0x42e/0x520 kernel/kthread.c:334
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287