INFO: task syz.7.3148:16858 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.7.3148      state:D stack:23832 pid:16858 ppid: 10801 flags:0x00004006
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5049 [inline]
 __schedule+0x11ef/0x43c0 kernel/sched/core.c:6395
 schedule+0x11b/0x1e0 kernel/sched/core.c:6478
 perf_pending_task_sync+0x13c/0x1c0 kernel/events/core.c:5127
 _free_event+0x34/0xe60 kernel/events/core.c:5133
 put_event kernel/events/core.c:5258 [inline]
 perf_event_release_kernel+0x83e/0x8d0 kernel/events/core.c:5383
 perf_release+0x37/0x40 kernel/events/core.c:5393
 __fput+0x234/0x930 fs/file_table.c:311
 task_work_run+0x125/0x1a0 kernel/task_work.c:188
 get_signal+0x1222/0x12c0 kernel/signal.c:2672
 arch_do_signal_or_restart+0xe7/0x12c0 arch/x86/kernel/signal.c:867
 handle_signal_work kernel/entry/common.c:154 [inline]
 exit_to_user_mode_loop+0x9e/0x130 kernel/entry/common.c:178
 exit_to_user_mode_prepare+0xee/0x180 kernel/entry/common.c:214
 __syscall_exit_to_user_mode_work kernel/entry/common.c:296 [inline]
 syscall_exit_to_user_mode+0x16/0x40 kernel/entry/common.c:307
 do_syscall_64+0x58/0xa0 arch/x86/entry/common.c:86
 entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7f1e0caffdd9
RSP: 002b:00007f1e0ad58fd8 EFLAGS: 00000202 ORIG_RAX: 0000000000000038
RAX: fffffffffffffffc RBX: 00007f1e0cd78fa0 RCX: 00007f1e0caffdd9
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 00000000c0126080
RBP: 00007f1e0cb95d69 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000000
R13: 00007f1e0cd79038 R14: 00007f1e0cd78fa0 R15: 00007ffd1dd1a278
 </TASK>

Showing all locks held in the system:
4 locks held by kworker/u4:0/9:
 #0: ffff888016dcd938 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work+0x761/0x1010 kernel/workqueue.c:-1
 #1: ffffc90000ce7d00 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work+0x79f/0x1010 kernel/workqueue.c:2285
 #2: ffffffff8d4314d0 (pernet_ops_rwsem){++++}-{3:3}, at: cleanup_net+0x148/0xba0 net/core/net_namespace.c:589
 #3: ffffffff8c3235a8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:290 [inline]
 #3: ffffffff8c3235a8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x2d1/0x750 kernel/rcu/tree_exp.h:845
1 lock held by khungtaskd/27:
 #0: ffffffff8c31eb20 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x0/0x30
2 locks held by getty/3948:
 #0: ffff88807f531098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:252
 #1: ffffc90002cf62e8 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x5df/0x1a70 drivers/tty/n_tty.c:2158
2 locks held by kworker/1:4/4228:
 #0: ffff888016c72138 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_one_work+0x761/0x1010 kernel/workqueue.c:-1
 #1: ffffc900030bfd00 ((work_completion)(&rew.rew_work)){+.+.}-{0:0}, at: process_one_work+0x79f/0x1010 kernel/workqueue.c:2285
3 locks held by kworker/0:19/15900:
 #0: ffff888016c70938 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x761/0x1010 kernel/workqueue.c:-1
 #1: ffffc9000342fd00 (fqdir_free_work){+.+.}-{0:0}, at: process_one_work+0x79f/0x1010 kernel/workqueue.c:2285
 #2: ffffffff8c3234b0 (rcu_state.barrier_mutex){+.+.}-{3:3}, at: rcu_barrier+0xa1/0x4c0 kernel/rcu/tree.c:4043
1 lock held by syz-executor/20026:
 #0: ffffffff8d43d3c8 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:72 [inline]
 #0: ffffffff8d43d3c8 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x7ee/0xf30 net/core/rtnetlink.c:5684
4 locks held by syz.8.3856/20166:
 #0: ffffffff8d4314d0 (pernet_ops_rwsem){++++}-{3:3}, at: copy_net_ns+0x32e/0x5b0 net/core/net_namespace.c:499
 #1: ffffffff8d43d3c8 (rtnl_mutex){+.+.}-{3:3}, at: caif_exit_net+0x66/0x480 net/caif/caif_dev.c:527
 #2: ffff888024f07780 (&caifn->caifdevs.lock){+.+.}-{3:3}, at: caif_exit_net+0x79/0x480 net/caif/caif_dev.c:528
 #3: ffffffff8c3235a8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:322 [inline]
 #3: ffffffff8c3235a8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x3a5/0x750 kernel/rcu/tree_exp.h:845
1 lock held by syz.0.3865/20193:
1 lock held by syz-executor/20258:
 #0: ffffffff8d43d3c8 (rtnl_mutex){+.+.}-{3:3}, at: __tun_chr_ioctl+0x3fc/0x1ec0 drivers/net/tun.c:3052
2 locks held by syz-executor/20283:
 #0: ffffffff8d4314d0 (pernet_ops_rwsem){++++}-{3:3}, at: copy_net_ns+0x32e/0x5b0 net/core/net_namespace.c:499
 #1: ffffffff8d43d3c8 (rtnl_mutex){+.+.}-{3:3}, at: register_nexthop_notifier+0x84/0x240 net/ipv4/nexthop.c:3620

=============================================

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 04/18/2026
Call Trace:
 <TASK>
 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+0xe0f/0xe50 kernel/hung_task.c:369
 kthread+0x436/0x520 kernel/kthread.c:334
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287
 </TASK>
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 20193 Comm: syz.0.3865 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026
RIP: 0010:__raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:117 [inline]
RIP: 0010:_raw_spin_lock_irqsave+0xb4/0x100 kernel/locking/spinlock.c:162
Code: f7 bf 01 00 00 00 e8 7b 3a 8c f7 48 8d 7b 18 31 f6 31 d2 31 c9 41 b8 01 00 00 00 45 31 c9 ff 75 08 e8 70 da 96 f7 48 83 c4 08 <48> 89 df e8 74 30 98 f7 48 c7 04 24 0e 36 e0 45 4b c7 04 27 00 00
RSP: 0018:ffffc90000dd0c40 EFLAGS: 00000092
RAX: 5e68b02d83a4c100 RBX: ffffffff96548bd0 RCX: 5e68b02d83a4c100
RDX: 0000000000000000 RSI: ffffffff8a2b3aa0 RDI: ffffffff8a79fe00
RBP: ffffc90000dd0cd8 R08: dffffc0000000000 R09: 1ffffffff203aa18
R10: dffffc0000000000 R11: fffffbfff203aa19 R12: dffffc0000000000
R13: ffff88807d653120 R14: 0000000000000806 R15: 1ffff920001ba188
FS:  00007f8e88dd26c0(0000) GS:ffff8880b9100000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007ffe67afce40 CR3: 0000000071f2c000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000200000000300 DR2: 0000200000000300
DR3: 0000200000000300 DR6: 00000000ffff0ff0 DR7: 0000000000000600
Call Trace:
 <IRQ>
 debug_object_deactivate+0x62/0x390 lib/debugobjects.c:749
 debug_hrtimer_deactivate kernel/time/hrtimer.c:415 [inline]
 __run_hrtimer kernel/time/hrtimer.c:1653 [inline]
 __hrtimer_run_queues+0x2b9/0xb70 kernel/time/hrtimer.c:1749
 hrtimer_interrupt+0x3bb/0x8d0 kernel/time/hrtimer.c:1811
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1097 [inline]
 __sysvec_apic_timer_interrupt+0x137/0x4a0 arch/x86/kernel/apic/apic.c:1114
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1108 [inline]
 sysvec_apic_timer_interrupt+0x9b/0xc0 arch/x86/kernel/apic/apic.c:1108
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:676
RIP: 0010:trace_lock_acquire include/trace/events/lock.h:13 [inline]
RIP: 0010:lock_acquire+0x3bf/0x400 kernel/locking/lockdep.c:5594
Code: 0c 4d 85 f6 74 40 49 83 c6 08 4c 89 f0 48 c1 e8 03 42 80 3c 38 00 74 08 4c 89 f7 e8 fb 3e 61 00 49 8b 3e 4c 89 e6 8b 54 24 1c <89> d9 4c 8b 44 24 28 4c 8b 4c 24 30 ff 75 10 ff 74 24 28 e8 a9 a7
RSP: 0018:ffffc90002dff620 EFLAGS: 00000246
RAX: 1ffff110040970d3 RBX: 0000000000000000 RCX: ffffffff815d1427
RDX: 0000000000000000 RSI: ffffffff8c31eb20 RDI: ffffffff8c1edac0
RBP: ffffc90002dff740 R08: ffffffff8d89f02f R09: 1ffffffff1b13e05
R10: dffffc0000000000 R11: fffffbfff1b13e06 R12: ffffffff8c31eb20
R13: 1ffff920005bfed0 R14: ffff8880204b8698 R15: dffffc0000000000
 rcu_lock_acquire+0x2a/0x30 include/linux/rcupdate.h:313
 rcu_read_lock include/linux/rcupdate.h:740 [inline]
 inet_twsk_purge+0x119/0x840 net/ipv4/inet_timewait_sock.c:268
 ops_exit_list net/core/net_namespace.c:177 [inline]
 setup_net+0x844/0xa10 net/core/net_namespace.c:365
 copy_net_ns+0x348/0x5b0 net/core/net_namespace.c:503
 create_new_namespaces+0x3d3/0x6f0 kernel/nsproxy.c:110
 copy_namespaces+0x37d/0x3e0 kernel/nsproxy.c:178
 copy_process+0x1834/0x3e20 kernel/fork.c:2293
 kernel_clone+0x23f/0x990 kernel/fork.c:2679
 __do_sys_clone kernel/fork.c:2796 [inline]
 __se_sys_clone kernel/fork.c:2780 [inline]
 __x64_sys_clone+0x19a/0x210 kernel/fork.c:2780
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7f8e8ab78dd9
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 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 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f8e88dd1fd8 EFLAGS: 00000206 ORIG_RAX: 0000000000000038
RAX: ffffffffffffffda RBX: 00007f8e8adf1fa0 RCX: 00007f8e8ab78dd9
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 00000000e50c1600
RBP: 00007f8e8ac0ed69 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000000
R13: 00007f8e8adf2038 R14: 00007f8e8adf1fa0 R15: 00007ffe17f46a08
 </TASK>