INFO: task syz.8.805:7644 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.8.805 state:D stack:24256 pid:7644 ppid:6728 flags:0x00004006
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+0xb7/0x1240 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: 0033:0x7f44853b7e80
RSP: 002b:00007f448629dc78 EFLAGS: 00000283
RAX: 0000000000000000 RBX: 00007f448629ed30 RCX: 00007f44855ab120
RDX: 00007f448629dc80 RSI: 00007f448629ddb0 RDI: 0000000000000021
RBP: 000000000000000b R08: 0000000000000000 R09: 0000000000000000
R10: 00000000ffffffff R11: 0000000000000000 R12: 0000000000000073
R13: 00007f448629eeb0 R14: 9999999999999999 R15: 0000000000000000
Showing all locks held in the system:
1 lock held by rcu_tasks_kthre/12:
#0: ffffffff8c92bab0 (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: ffffffff8c92c2d0 (rcu_tasks_trace.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x33/0xf00 kernel/rcu/tasks.h:517
2 locks held by kworker/1:0/22:
#0: ffff888017472138 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267
#1: ffffc900001c7d00 ((work_completion)(&rew->rew_work)){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267
1 lock held by khungtaskd/28:
#0: ffffffff8c92b120 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:350 [inline]
#0: ffffffff8c92b120 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:791 [inline]
#0: ffffffff8c92b120 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x51/0x290 kernel/locking/lockdep.c:6513
2 locks held by getty/4023:
#0: ffff8880303ea098 (&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
4 locks held by kworker/u4:29/10721:
#0: ffff888017616938 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267
#1: ffffc9000c85fd00 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267
#2: ffffffff8db2e6d0 (pernet_ops_rwsem){++++}-{3:3}, at: cleanup_net+0x132/0xb80 net/core/net_namespace.c:594
#3: ffffffff8c930cc0 (rcu_state.barrier_mutex){+.+.}-{3:3}, at: rcu_barrier+0x48/0x600 kernel/rcu/tree.c:4023
2 locks held by syz.6.1738/11397:
#0: ffffffff8db3b3a8 (rtnl_mutex){+.+.}-{3:3}, at: tun_detach drivers/net/tun.c:698 [inline]
#0: ffffffff8db3b3a8 (rtnl_mutex){+.+.}-{3:3}, at: tun_chr_close+0x3d/0x1b0 drivers/net/tun.c:3492
#1: ffffffff8c930df8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:291 [inline]
#1: ffffffff8c930df8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x455/0x830 kernel/rcu/tree_exp.h:962
2 locks held by syz.2.1743/11417:
#0: ffffffff8db2e6d0 (pernet_ops_rwsem){++++}-{3:3}, at: copy_net_ns+0x32e/0x5b0 net/core/net_namespace.c:504
#1: ffffffff8c930df8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:323 [inline]
#1: ffffffff8c930df8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x346/0x830 kernel/rcu/tree_exp.h:962
6 locks held by syz.7.1744/11414:
=============================================
NMI backtrace for cpu 1
CPU: 1 PID: 28 Comm: khungtaskd Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
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 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 11417 Comm: syz.2.1743 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
RIP: 0010:debug_object_assert_init+0x1da/0x2f0 lib/debugobjects.c:-1
Code: 42 80 3c 38 00 74 08 48 89 ef e8 31 7d c5 fd 48 8b 55 00 48 39 d3 0f 92 c0 48 8d 8a 00 80 00 00 48 39 cb 0f 93 c1 08 c1 74 44 <4c> 8b 34 24 48 8b 7c 24 10 48 8b 74 24 08 e8 d3 e8 0e 06 4d 85 ed
RSP: 0018:ffffc900044b7678 EFLAGS: 00000046
RAX: 1ffff11005f51eb9 RBX: ffff88807c4cee08 RCX: dffffc0000000000
RDX: 0000000000000001 RSI: 0000000000000004 RDI: ffffc900044b7560
RBP: ffffffff96c7aab0 R08: 0000000000000004 R09: 0000000000000003
R10: fffff52000896eac R11: 1ffff92000896eac R12: ffff88802fa8f5c8
R13: ffff88802fa8f5b0 R14: 0000000000000001 R15: dffffc0000000000
FS: 00007f0d0fbe26c0(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f0d0fc03990 CR3: 0000000057893000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000200000000300 DR2: 0000200000000300
DR3: 0000200000000300 DR6: 00000000ffff0ff0 DR7: 0000000000000600
Call Trace:
debug_timer_assert_init kernel/time/timer.c:792 [inline]
debug_assert_init kernel/time/timer.c:837 [inline]
__try_to_del_timer_sync+0x47/0x1f0 kernel/time/timer.c:1412
__timer_delete_sync+0x1fb/0x2c0 kernel/time/timer.c:1574
del_timer_sync include/linux/timer.h:200 [inline]
can_pernet_exit+0x38/0xc0 net/can/af_can.c:827
ops_exit_list net/core/net_namespace.c:172 [inline]
setup_net+0x8f9/0xbb0 net/core/net_namespace.c:368
copy_net_ns+0x348/0x5b0 net/core/net_namespace.c:508
create_new_namespaces+0x3d3/0x6f0 kernel/nsproxy.c:110
copy_namespaces+0x3b0/0x410 kernel/nsproxy.c:178
copy_process+0x199c/0x4020 kernel/fork.c:2354
kernel_clone+0x225/0x8b0 kernel/fork.c:2757
__do_sys_clone kernel/fork.c:2898 [inline]
__se_sys_clone kernel/fork.c:2882 [inline]
__x64_sys_clone+0x17c/0x1d0 kernel/fork.c:2882
do_syscall_x64 arch/x86/entry/common.c:51 [inline]
do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:81
entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f0d0ed8f749
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f0d0fbe1fe8 EFLAGS: 00000206 ORIG_RAX: 0000000000000038
RAX: ffffffffffffffda RBX: 00007f0d0efe6090 RCX: 00007f0d0ed8f749
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 00000010eb22b000
RBP: 00007f0d0ee13f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000000
R13: 00007f0d0efe6128 R14: 00007f0d0efe6090 R15: 00007fff6699d1a8