INFO: task syz.4.1381:9601 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.4.1381      state:D stack:25968 pid: 9601 ppid:  4189 flags:0x00004002
Call Trace:
 <TASK>
 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:5127
 _free_event+0x34/0xe30 kernel/events/core.c:5133
 put_event kernel/events/core.c:5258 [inline]
 perf_event_release_kernel+0x7c4/0x850 kernel/events/core.c:5383
 perf_release+0x37/0x40 kernel/events/core.c:5393
 __fput+0x212/0x8c0 fs/file_table.c:311
 task_work_run+0x125/0x1a0 kernel/task_work.c:188
 exit_task_work include/linux/task_work.h:33 [inline]
 do_exit+0x635/0x2110 kernel/exit.c:884
 do_group_exit+0x12c/0x2f0 kernel/exit.c:998
 get_signal+0x7eb/0x12e0 kernel/signal.c:2901
 arch_do_signal_or_restart+0xe6/0x12a0 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: 0033:0x7fc06cc90e99
RSP: 002b:00007fc06aee9028 EFLAGS: 00000246 ORIG_RAX: 0000000000000029
RAX: 000000000000000a RBX: 00007fc06cf18fa0 RCX: 00007fc06cc90e99
RDX: 0000000000000000 RSI: 0000000000000002 RDI: 000000000000000a
RBP: 00007fc06cd26eaf R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fc06cf19038 R14: 00007fc06cf18fa0 R15: 00007ffd9f925ac8
 </TASK>

Showing all locks held in the system:
3 locks held by kworker/0:0/7:
 #0: ffff888016c70938 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x75c/0xff0 kernel/workqueue.c:-1
 #1: ffffc90000cc7d00 ((work_completion)(&(&nsim_dev->trap_data->trap_report_dw)->work)){+.+.}-{0:0}, at: process_one_work+0x79e/0xff0 kernel/workqueue.c:2285
 #2: ffff888020840400 (&nsim_dev->port_list_lock){+.+.}-{3:3}, at: nsim_dev_trap_report_work+0x56/0xab0 drivers/net/netdevsim/dev.c:757
1 lock held by khungtaskd/27:
 #0: ffffffff8c31ef20 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x0/0x30
2 locks held by getty/3949:
 #0: ffff88802cc3c098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:252
 #1: ffffc900026562e8 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x594/0x1a50 drivers/tty/n_tty.c:2158
8 locks held by kworker/u4:6/4268:
 #0: ffff888016dcd938 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work+0x75c/0xff0 kernel/workqueue.c:-1
 #1: ffffc9000327fd00 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work+0x79e/0xff0 kernel/workqueue.c:2285
 #2: ffffffff8d43f210 (pernet_ops_rwsem){++++}-{3:3}, at: cleanup_net+0x148/0xba0 net/core/net_namespace.c:589
 #3: ffffffff8d470728 (devlink_mutex){+.+.}-{3:3}, at: devlink_pernet_pre_exit+0xa4/0x310 net/core/devlink.c:11534
 #4: ffff88802097f660 (&nsim_bus_dev->nsim_bus_reload_lock){+.+.}-{3:3}, at: nsim_dev_reload_down+0x57/0x160 drivers/net/netdevsim/dev.c:870
 #5: ffff888020840400 (&nsim_dev->port_list_lock){+.+.}-{3:3}, at: nsim_dev_port_del_all drivers/net/netdevsim/dev.c:1359 [inline]
 #5: ffff888020840400 (&nsim_dev->port_list_lock){+.+.}-{3:3}, at: nsim_dev_reload_destroy+0x109/0x230 drivers/net/netdevsim/dev.c:1561
 #6: ffffffff8d44b148 (rtnl_mutex){+.+.}-{3:3}, at: nsim_destroy+0x3b/0x150 drivers/net/netdevsim/netdev.c:381
 #7: ffffffff8c3239a8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:322 [inline]
 #7: ffffffff8c3239a8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x3a5/0x750 kernel/rcu/tree_exp.h:845
2 locks held by kworker/0:7/5402:
 #0: ffff888016c72138 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_one_work+0x75c/0xff0 kernel/workqueue.c:-1
 #1: ffffc900032dfd00 ((work_completion)(&rew.rew_work)){+.+.}-{0:0}, at: process_one_work+0x79e/0xff0 kernel/workqueue.c:2285
1 lock held by syz.2.2811/15013:
1 lock held by syz-executor/15265:
 #0: ffffffff8d44b148 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:72 [inline]
 #0: ffffffff8d44b148 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x7d6/0xf00 net/core/rtnetlink.c:5685
2 locks held by syz.5.2893/15322:
 #0: ffffffff8c36c5e8 (event_mutex){+.+.}-{3:3}, at: perf_trace_destroy+0x2a/0x140 kernel/trace/trace_event_perf.c:239
 #1: ffffffff8c3239a8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:290 [inline]
 #1: ffffffff8c3239a8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x2d1/0x750 kernel/rcu/tree_exp.h:845
1 lock held by syz.3.2894/15327:
 #0: ffffffff8c36c5e8 (event_mutex){+.+.}-{3:3}, at: perf_trace_destroy+0x2a/0x140 kernel/trace/trace_event_perf.c:239

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

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 06/25/2026
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+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
 </TASK>
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 15013 Comm: syz.2.2811 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/25/2026
RIP: 0010:on_stack arch/x86/include/asm/stacktrace.h:55 [inline]
RIP: 0010:unwind_next_frame+0x110f/0x1cf0 arch/x86/kernel/unwind_orc.c:609
Code: 48 8d 7b 38 48 8b 44 24 28 0f 85 ee 00 00 00 42 80 3c 28 00 74 05 e8 e0 f1 88 00 4c 8b 7b 38 48 8d 7b 08 48 89 f8 48 c1 e8 03 <42> 80 3c 28 00 74 05 e8 c5 f1 88 00 4c 8b 63 08 4c 8d 73 10 4c 89
RSP: 0018:ffffc9000360ec58 EFLAGS: 00000a02
RAX: 1ffff920006c1db5 RBX: ffffc9000360eda0 RCX: 0000000000000001
RDX: ffffc9000360ede0 RSI: ffffc9000360ef48 RDI: ffffc9000360eda8
RBP: dffffc0000000000 R08: ffffc9000360ef48 R09: ffffc9000360edf0
R10: dffffc0000000000 R11: fffff520006c1dc0 R12: ffffffff8e0cbfa9
R13: dffffc0000000000 R14: ffffc9000360edd5 R15: ffffc9000360ef58
FS:  00007f7a389e76c0(0000) GS:ffff8880b9100000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f9aed98dd58 CR3: 000000005dbdc000 CR4: 00000000003506e0
DR0: 0000000000000004 DR1: 0000200000000300 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600
Call Trace:
 <TASK>
 __unwind_start+0x51a/0x650 arch/x86/kernel/unwind_orc.c:704
 unwind_start arch/x86/include/asm/unwind.h:60 [inline]
 perf_callchain_kernel+0x2f4/0x760 arch/x86/events/core.c:2780
 get_perf_callchain+0x356/0x460 kernel/events/callchain.c:200
 perf_callchain kernel/events/core.c:7606 [inline]
 perf_prepare_sample+0x352/0x1cb0 kernel/events/core.c:7633
 __perf_event_output kernel/events/core.c:7802 [inline]
 perf_event_output_forward+0x185/0x2e0 kernel/events/core.c:7822
 __perf_event_overflow+0x35f/0x550 kernel/events/core.c:9515
 perf_swevent_overflow kernel/events/core.c:9591 [inline]
 perf_swevent_event+0x4b8/0x540 kernel/events/core.c:9629
 perf_tp_event+0x324/0xbe0 kernel/events/core.c:10047
 perf_trace_run_bpf_submit+0xf3/0x1c0 kernel/events/core.c:10021
 perf_trace_lock_acquire+0x341/0x3f0 include/trace/events/lock.h:13
 trace_lock_acquire include/trace/events/lock.h:13 [inline]
 lock_acquire+0x3d7/0x400 kernel/locking/lockdep.c:5594
 rcu_lock_acquire+0x2a/0x30 include/linux/rcupdate.h:313
 rcu_read_lock include/linux/rcupdate.h:740 [inline]
 inet_twsk_purge+0x10d/0x820 net/ipv4/inet_timewait_sock.c:268
 ops_exit_list net/core/net_namespace.c:177 [inline]
 setup_net+0x842/0xa10 net/core/net_namespace.c:365
 copy_net_ns+0x33e/0x5b0 net/core/net_namespace.c:503
 create_new_namespaces+0x3ce/0x700 kernel/nsproxy.c:110
 copy_namespaces+0x378/0x3d0 kernel/nsproxy.c:178
 copy_process+0x1844/0x3ec0 kernel/fork.c:2294
 kernel_clone+0x23f/0x990 kernel/fork.c:2681
 __do_sys_clone kernel/fork.c:2798 [inline]
 __se_sys_clone kernel/fork.c:2782 [inline]
 __x64_sys_clone+0x19a/0x210 kernel/fork.c:2782
 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: 0033:0x7f7a3a78ee99
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:00007f7a389e6fd8 EFLAGS: 00000206 ORIG_RAX: 0000000000000038
RAX: ffffffffffffffda RBX: 00007f7a3aa16fa0 RCX: 00007f7a3a78ee99
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000041064400
RBP: 00007f7a3a824eaf R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000000
R13: 00007f7a3aa17038 R14: 00007f7a3aa16fa0 R15: 00007ffd7693be48
 </TASK>