INFO: task syz.2.719:6836 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.2.719 state:D stack:26320 pid:6836 ppid:4267 flags:0x00004002
Call Trace:
context_switch kernel/sched/core.c:5244 [inline]
__schedule+0x10ec/0x40b0 kernel/sched/core.c:6561
schedule+0xb9/0x180 kernel/sched/core.c:6637
perf_pending_task_sync kernel/events/core.c:5031 [inline]
_free_event+0x171/0x10a0 kernel/events/core.c:5037
put_event kernel/events/core.c:5162 [inline]
perf_event_release_kernel+0x832/0x8c0 kernel/events/core.c:5287
perf_release+0x37/0x40 kernel/events/core.c:5297
__fput+0x22c/0x920 fs/file_table.c:320
task_work_run+0x1ca/0x250 kernel/task_work.c:203
exit_task_work include/linux/task_work.h:39 [inline]
do_exit+0x93e/0x2400 kernel/exit.c:880
do_group_exit+0x217/0x2d0 kernel/exit.c:1022
get_signal+0x1272/0x1350 kernel/signal.c:2871
arch_do_signal_or_restart+0xb0/0x1230 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:87
entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f2b47f8eec9
RSP: 002b:00007f2b48dc0038 EFLAGS: 00000246 ORIG_RAX: 000000000000012a
RAX: 0000000000000007 RBX: 00007f2b481e5fa0 RCX: 00007f2b47f8eec9
RDX: ffffffffffffffff RSI: 0000000000000000 RDI: 0000200000000000
RBP: 00007f2b48011f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000006 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f2b481e6038 R14: 00007f2b481e5fa0 R15: 00007ffe75beda78
Showing all locks held in the system:
1 lock held by rcu_tasks_kthre/12:
#0: ffffffff8cb2b570 (rcu_tasks.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x33/0xf00 kernel/rcu/tasks.h:517
1 lock held by rcu_tasks_trace/13:
#0: ffffffff8cb2bd90 (rcu_tasks_trace.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x33/0xf00 kernel/rcu/tasks.h:517
1 lock held by khungtaskd/28:
#0: ffffffff8cb2abe0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:350 [inline]
#0: ffffffff8cb2abe0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:791 [inline]
#0: ffffffff8cb2abe0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x51/0x290 kernel/locking/lockdep.c:6513
2 locks held by kworker/u4:2/31:
2 locks held by kworker/u4:4/56:
2 locks held by getty/4030:
#0: ffff88814ceb3098 (&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+0x41b/0x1380 drivers/tty/n_tty.c:2198
3 locks held by kworker/u4:6/4357:
#0: ffff888017479138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267
#1: ffffc90004507d00 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267
#2: ffffffff8dd41268 (rtnl_mutex){+.+.}-{3:3}, at: linkwatch_event+0xa/0x50 net/core/link_watch.c:263
2 locks held by kworker/1:5/4385:
#0: ffff888017472138 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267
#1: ffffc90004527d00 ((work_completion)(&rew->rew_work)){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267
2 locks held by syz.7.1244/8693:
#0: ffffffff8dd41268 (rtnl_mutex){+.+.}-{3:3}, at: tun_detach drivers/net/tun.c:698 [inline]
#0: ffffffff8dd41268 (rtnl_mutex){+.+.}-{3:3}, at: tun_chr_close+0x3d/0x1b0 drivers/net/tun.c:3492
#1: ffffffff8cb308b8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:291 [inline]
#1: ffffffff8cb308b8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x455/0x830 kernel/rcu/tree_exp.h:962
2 locks held by syz.9.1247/8708:
#0: ffffffff8dd34590 (pernet_ops_rwsem){++++}-{3:3}, at: copy_net_ns+0x32e/0x5b0 net/core/net_namespace.c:504
#1: ffffffff8dd41268 (rtnl_mutex){+.+.}-{3:3}, at: ip_tunnel_init_net+0x281/0x740 net/ipv4/ip_tunnel.c:1117
1 lock held by syz.3.1249/8716:
#0: ffffffff8dd41268 (rtnl_mutex){+.+.}-{3:3}, at: __netlink_dump_start+0x11f/0x6f0 net/netlink/af_netlink.c:2305
2 locks held by syz.2.1248/8722:
1 lock held by syz.8.1251/8724:
#0: ffffffff8dd41268 (rtnl_mutex){+.+.}-{3:3}, at: tun_detach drivers/net/tun.c:698 [inline]
#0: ffffffff8dd41268 (rtnl_mutex){+.+.}-{3:3}, at: tun_chr_close+0x3d/0x1b0 drivers/net/tun.c:3492
2 locks held by syz.8.1251/8727:
#0: ffffffff8d5922e8 (ppp_mutex){+.+.}-{3:3}, at: ppp_ioctl+0xca/0x1940 drivers/net/ppp/ppp_generic.c:739
#1: ffffffff8dd41268 (rtnl_mutex){+.+.}-{3:3}, at: ppp_create_interface drivers/net/ppp/ppp_generic.c:3360 [inline]
#1: ffffffff8dd41268 (rtnl_mutex){+.+.}-{3:3}, at: ppp_unattached_ioctl drivers/net/ppp/ppp_generic.c:1070 [inline]
#1: ffffffff8dd41268 (rtnl_mutex){+.+.}-{3:3}, at: ppp_ioctl+0x64f/0x1940 drivers/net/ppp/ppp_generic.c:743
1 lock held by syz.8.1251/8729:
#0: ffffffff8d5922e8 (ppp_mutex){+.+.}-{3:3}, at: ppp_ioctl+0xca/0x1940 drivers/net/ppp/ppp_generic.c:739
2 locks held by syz.8.1251/8730:
#0: ffffffff8dd272a8 (br_ioctl_mutex){+.+.}-{3:3}, at: br_ioctl_call net/socket.c:1176 [inline]
#0: ffffffff8dd272a8 (br_ioctl_mutex){+.+.}-{3:3}, at: sock_ioctl+0x2ce/0x6e0 net/socket.c:1275
#1: ffffffff8dd41268 (rtnl_mutex){+.+.}-{3:3}, at: br_ioctl_stub+0x9f/0x9e0 net/bridge/br_ioctl.c:402
1 lock held by syz.8.1251/8731:
#0: ffffffff8dd41268 (rtnl_mutex){+.+.}-{3:3}, at: dev_ioctl+0x567/0xea0 net/core/dev_ioctl.c:587
1 lock held by syz.8.1251/8733:
#0: ffffffff8dd41268 (rtnl_mutex){+.+.}-{3:3}, at: dev_ioctl+0x567/0xea0 net/core/dev_ioctl.c:587
1 lock held by syz.2.1252/8726:
#0: ffffffff8dd41268 (rtnl_mutex){+.+.}-{3:3}, at: __tun_chr_ioctl+0x3ab/0x1e10 drivers/net/tun.c:3104
=============================================
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 08/18/2025
Call Trace:
dump_stack_lvl+0x168/0x22e lib/dump_stack.c:106
nmi_cpu_backtrace+0x3f4/0x470 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+0xeee/0xf30 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: 21 Comm: ksoftirqd/1 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025
RIP: 0010:__preempt_count_add kernel/rcu/tree.c:717 [inline]
RIP: 0010:rcu_is_watching+0x0/0xa0 kernel/rcu/tree.c:720
Code: ff ff eb 99 e8 81 84 ac 08 48 c7 c7 e0 16 b3 8c 4c 89 f6 e8 12 92 c3 02 e9 53 ff ff ff 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 00 <41> 57 41 56 53 65 ff 05 fc 60 97 7e e8 ff 98 ac 08 89 c3 83 f8 08
RSP: 0018:ffffc900001b7980 EFLAGS: 00000002
RAX: ffffffff81533081 RBX: 0000000000000001 RCX: 0000000000000100
RDX: ffff888017741dc0 RSI: 0000000000000001 RDI: 0000000000000000
RBP: 0000000000000000 R08: dffffc0000000000 R09: ffffed10171e7461
R10: ffffed10171e7461 R11: 1ffff110171e7460 R12: 0000000000000100
R13: ffff8880b8f3f800 R14: ffff8880b8f3a360 R15: ffff888026e39560
FS: 0000000000000000(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fa5fd044e9c CR3: 000000007bbac000 CR4: 00000000003506e0
DR0: 0000200000000300 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600
Call Trace:
rcu_read_unlock include/linux/rcupdate.h:820 [inline]
__queue_work+0xbda/0xfb0 kernel/workqueue.c:1524
call_timer_fn+0x1a0/0x670 kernel/time/timer.c:1504
expire_timers kernel/time/timer.c:1544 [inline]
__run_timers+0x550/0x7c0 kernel/time/timer.c:1820
run_timer_softirq+0x63/0xf0 kernel/time/timer.c:1833
handle_softirqs+0x2a1/0x920 kernel/softirq.c:596
run_ksoftirqd+0x98/0xf0 kernel/softirq.c:963
smpboot_thread_fn+0x64a/0xa40 kernel/smpboot.c:164
kthread+0x29d/0x330 kernel/kthread.c:376
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295