INFO: task kworker/0:2:16819 blocked for more than 145 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/0:2     state:D stack:25336 pid:16819 ppid:     2 flags:0x00004000
Workqueue: events nsim_dev_trap_report_work
Call Trace:
 <TASK>
 </TASK>

Showing all locks held in the system:
1 lock held by khungtaskd/27:
 #0: ffffffff8c31eaa0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x0/0x30
4 locks held by kworker/u4:1/144:
 #0: ffff888016dcd938 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work+0x761/0x1010 kernel/workqueue.c:-1
 #1: ffffc900016ffd00 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work+0x79f/0x1010 kernel/workqueue.c:2285
 #2: ffffffff8d4308d0 (pernet_ops_rwsem){++++}-{3:3}, at: cleanup_net+0x148/0xba0 net/core/net_namespace.c:589
 #3: ffffffff8d43c548 (rtnl_mutex){+.+.}-{3:3}, at: ieee80211_unregister_hw+0x4d/0x220 net/mac80211/main.c:1392
2 locks held by getty/3946:
 #0: ffff88814cbaf098 (&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+0x5df/0x1a70 drivers/tty/n_tty.c:2158
3 locks held by kworker/1:6/4248:
 #0: ffff888016c70938 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x761/0x1010 kernel/workqueue.c:-1
 #1: ffffc900032bfd00 ((work_completion)(&pwq->unbound_release_work)){+.+.}-{0:0}, at: process_one_work+0x79f/0x1010 kernel/workqueue.c:2285
 #2: ffffffff8c323528 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:322 [inline]
 #2: ffffffff8c323528 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x3a5/0x750 kernel/rcu/tree_exp.h:845
2 locks held by kworker/u4:7/5331:
2 locks held by kworker/1:1/17050:
 #0: ffff888016c72138 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_one_work+0x761/0x1010 kernel/workqueue.c:-1
 #1: ffffc9000329fd00 ((work_completion)(&rew.rew_work)){+.+.}-{0:0}, at: process_one_work+0x79f/0x1010 kernel/workqueue.c:2285
2 locks held by syz.1.4359/18022:
5 locks held by syz-executor/19036:
 #0: ffff88807ec52460 (sb_writers#8){.+.+}-{0:0}, at: vfs_write+0x295/0xd60 fs/read_write.c:590
 #1: ffff88805922d488 (&of->mutex){+.+.}-{3:3}, at: kernfs_fop_write_iter+0x1e5/0x4c0 fs/kernfs/file.c:287
 #2: ffff888023d8d748 (kn->active#284){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x208/0x4c0 fs/kernfs/file.c:288
 #3: ffffffff8cd79ca8 (nsim_bus_dev_list_lock){+.+.}-{3:3}, at: del_device_store+0xd3/0x3a0 drivers/net/netdevsim/bus.c:344
 #4: ffff88801a7e8178 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:764 [inline]
 #4: ffff88801a7e8178 (&dev->mutex){....}-{3:3}, at: __device_driver_lock drivers/base/dd.c:1044 [inline]
 #4: ffff88801a7e8178 (&dev->mutex){....}-{3:3}, at: device_release_driver_internal+0xb0/0x750 drivers/base/dd.c:1259
2 locks held by syz.4.4581/19191:
 #0: ffffffff8d4308d0 (pernet_ops_rwsem){++++}-{3:3}, at: copy_net_ns+0x32e/0x5b0 net/core/net_namespace.c:499
 #1: ffffffff8c323430 (rcu_state.barrier_mutex){+.+.}-{3:3}, at: rcu_barrier+0xa1/0x4c0 kernel/rcu/tree.c:4043
4 locks held by syz-executor/19265:
 #0: ffff88807ec52460 (sb_writers#8){.+.+}-{0:0}, at: vfs_write+0x295/0xd60 fs/read_write.c:590
 #1: ffff88814801f088 (&of->mutex){+.+.}-{3:3}, at: kernfs_fop_write_iter+0x1e5/0x4c0 fs/kernfs/file.c:287
 #2: ffff888023d8d748 (kn->active#284){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x208/0x4c0 fs/kernfs/file.c:288
 #3: ffffffff8cd79ca8 (nsim_bus_dev_list_lock){+.+.}-{3:3}, at: del_device_store+0xd3/0x3a0 drivers/net/netdevsim/bus.c:344
4 locks held by syz-executor/19299:
 #0: ffff88807ec52460 (sb_writers#8){.+.+}-{0:0}, at: vfs_write+0x295/0xd60 fs/read_write.c:590
 #1: ffff888059093088 (&of->mutex){+.+.}-{3:3}, at: kernfs_fop_write_iter+0x1e5/0x4c0 fs/kernfs/file.c:287
 #2: ffff888023d8d748 (kn->active#284){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x208/0x4c0 fs/kernfs/file.c:288
 #3: ffffffff8cd79ca8 (nsim_bus_dev_list_lock){+.+.}-{3:3}, at: del_device_store+0xd3/0x3a0 drivers/net/netdevsim/bus.c:344
4 locks held by syz-executor/19356:
 #0: ffff88807ec52460 (sb_writers#8){.+.+}-{0:0}, at: vfs_write+0x295/0xd60 fs/read_write.c:590
 #1: ffff888024566488 (&of->mutex){+.+.}-{3:3}, at: kernfs_fop_write_iter+0x1e5/0x4c0 fs/kernfs/file.c:287
 #2: ffff888023d8d748 (kn->active#284){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x208/0x4c0 fs/kernfs/file.c:288
 #3: ffffffff8cd79ca8 (nsim_bus_dev_list_lock){+.+.}-{3:3}, at: del_device_store+0xd3/0x3a0 drivers/net/netdevsim/bus.c:344
4 locks held by syz-executor/19400:
 #0: ffff88807ec52460 (sb_writers#8){.+.+}-{0:0}, at: vfs_write+0x295/0xd60 fs/read_write.c:590
 #1: ffff88807a6e5488 (&of->mutex){+.+.}-{3:3}, at: kernfs_fop_write_iter+0x1e5/0x4c0 fs/kernfs/file.c:287
 #2: ffff888023d8d748 (kn->active#284){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x208/0x4c0 fs/kernfs/file.c:288
 #3: ffffffff8cd79ca8 (nsim_bus_dev_list_lock){+.+.}-{3:3}, at: del_device_store+0xd3/0x3a0 drivers/net/netdevsim/bus.c:344
4 locks held by syz-executor/19461:
 #0: ffff88807ec52460 (sb_writers#8){.+.+}-{0:0}, at: vfs_write+0x295/0xd60 fs/read_write.c:590
 #1: ffff88805fcd1c88 (&of->mutex){+.+.}-{3:3}, at: kernfs_fop_write_iter+0x1e5/0x4c0 fs/kernfs/file.c:287
 #2: ffff888023d8d748 (kn->active#284){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x208/0x4c0 fs/kernfs/file.c:288
 #3: ffffffff8cd79ca8 (nsim_bus_dev_list_lock){+.+.}-{3:3}, at: del_device_store+0xd3/0x3a0 drivers/net/netdevsim/bus.c:344
4 locks held by syz-executor/19463:
 #0: ffff88807ec52460 (sb_writers#8){.+.+}-{0:0}, at: vfs_write+0x295/0xd60 fs/read_write.c:590
 #1: ffff88808f623c88 (&of->mutex){+.+.}-{3:3}, at: kernfs_fop_write_iter+0x1e5/0x4c0 fs/kernfs/file.c:287
 #2: ffff888023d8d748 (kn->active#284){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x208/0x4c0 fs/kernfs/file.c:288
 #3: ffffffff8cd79ca8 (nsim_bus_dev_list_lock){+.+.}-{3:3}, at: del_device_store+0xd3/0x3a0 drivers/net/netdevsim/bus.c:344
4 locks held by syz-executor/19501:
 #0: ffff88807ec52460 (sb_writers#8){.+.+}-{0:0}, at: vfs_write+0x295/0xd60 fs/read_write.c:590
 #1: ffff8880615d9c88 (&of->mutex){+.+.}-{3:3}, at: kernfs_fop_write_iter+0x1e5/0x4c0 fs/kernfs/file.c:287
 #2: ffff888023d8d748 (kn->active#284){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x208/0x4c0 fs/kernfs/file.c:288
 #3: ffffffff8cd79ca8 (nsim_bus_dev_list_lock){+.+.}-{3:3}, at: del_device_store+0xd3/0x3a0 drivers/net/netdevsim/bus.c:344
4 locks held by syz-executor/19544:
 #0: ffff88807ec52460 (sb_writers#8){.+.+}-{0:0}, at: vfs_write+0x295/0xd60 fs/read_write.c:590
 #1: ffff888031e9d488 (&of->mutex){+.+.}-{3:3}, at: kernfs_fop_write_iter+0x1e5/0x4c0 fs/kernfs/file.c:287
 #2: ffff888023d8d748 (kn->active#284){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x208/0x4c0 fs/kernfs/file.c:288
 #3: ffffffff8cd79ca8 (nsim_bus_dev_list_lock){+.+.}-{3:3}, at: del_device_store+0xd3/0x3a0 drivers/net/netdevsim/bus.c:344
2 locks held by rm/19640:

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

NMI backtrace for cpu 1
CPU: 1 PID: 27 Comm: khungtaskd Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
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 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 18022 Comm: syz.1.4359 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
RIP: 0010:lockdep_enabled kernel/locking/lockdep.c:91 [inline]
RIP: 0010:lock_release+0x10c/0x8a0 kernel/locking/lockdep.c:5636
Code: 65 8b 05 e7 f3 a4 7e 85 c0 0f 85 aa 04 00 00 65 48 8b 1d 57 ea a4 7e 4c 8d b3 ec 0a 00 00 4c 89 f0 48 c1 e8 03 42 0f b6 04 28 <84> c0 0f 85 47 05 00 00 41 83 3e 00 0f 85 7d 04 00 00 48 89 5c 24
RSP: 0018:ffffc90000006ce0 EFLAGS: 00000803
RAX: 0000000000000000 RBX: ffff88802c3bd940 RCX: 88728bb57a913a00
RDX: 0000000000000000 RSI: ffffffff8a79f760 RDI: ffffffff8a79f720
RBP: ffffc90000006df0 R08: ffffffff8d89d8af R09: 1ffffffff1b13b15
R10: dffffc0000000000 R11: fffffbfff1b13b16 R12: 1ffff92000000da8
R13: dffffc0000000000 R14: ffff88802c3be42c R15: 1ffff92000000da8
FS:  00007fd2f35d76c0(0000) GS:ffff8880b9000000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f86c527e368 CR3: 000000006389f000 CR4: 00000000003506f0
DR0: 0000200000000300 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff1 DR7: 0000000000000600
Call Trace:
 <IRQ>
 seqcount_lockdep_reader_access+0xe0/0x1d0 include/linux/seqlock.h:104
 timekeeping_get_delta kernel/time/timekeeping.c:254 [inline]
 timekeeping_get_ns kernel/time/timekeeping.c:388 [inline]
 ktime_get_update_offsets_now+0x95/0x3e0 kernel/time/timekeeping.c:2303
 hrtimer_update_base kernel/time/hrtimer.c:621 [inline]
 hrtimer_interrupt+0x130/0x8d0 kernel/time/hrtimer.c:1793
 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+0x4d/0xc0 arch/x86/kernel/apic/apic.c:1108
 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:676
RIP: 0010:get_stack_info+0x0/0xf0 arch/x86/kernel/dumpstack_64.c:193
Code: 73 0b 89 c0 48 8b 04 c5 68 75 25 8a c3 83 c7 fb 83 ff 05 77 0b 89 f8 48 8b 04 c5 c0 73 25 8a c3 31 c0 c3 0f 1f 80 00 00 00 00 <41> 57 41 56 41 55 41 54 53 48 89 cb 49 89 d6 49 89 f7 48 85 f6 74
RSP: 0018:ffffc90000007140 EFLAGS: 00000246
RAX: 1ffff92000000e46 RBX: ffffc90000007208 RCX: ffffc90000007228
RDX: ffffc90000007208 RSI: ffff88802c3bd940 RDI: ffffc900035ef190
RBP: ffffc90000007250 R08: 000000000000000f R09: 000000000000000e
R10: dffffc0000000000 R11: fffff52000000e4d R12: 1ffffffff1d2d174
R13: ffffc90000008000 R14: ffffc90000000000 R15: ffffc900035ef190
 stack_access_ok arch/x86/kernel/unwind_orc.c:348 [inline]
 deref_stack_reg arch/x86/kernel/unwind_orc.c:357 [inline]
 unwind_next_frame+0x9b4/0x1d90 arch/x86/kernel/unwind_orc.c:539
 arch_stack_walk+0x10c/0x140 arch/x86/kernel/stacktrace.c:25
 stack_trace_save+0xa6/0xf0 kernel/stacktrace.c:122
 kasan_save_stack mm/kasan/common.c:38 [inline]
 kasan_set_track mm/kasan/common.c:46 [inline]
 set_alloc_info mm/kasan/common.c:434 [inline]
 __kasan_slab_alloc+0x9c/0xd0 mm/kasan/common.c:467
 kasan_slab_alloc include/linux/kasan.h:254 [inline]
 slab_post_alloc_hook+0x4c/0x380 mm/slab.h:519
 slab_alloc_node mm/slub.c:3225 [inline]
 slab_alloc mm/slub.c:3233 [inline]
 kmem_cache_alloc+0x100/0x290 mm/slub.c:3238
 __skb_ext_alloc net/core/skbuff.c:6491 [inline]
 skb_ext_add+0x141/0x910 net/core/skbuff.c:6586
 nf_bridge_alloc include/net/netfilter/br_netfilter.h:12 [inline]
 br_nf_pre_routing_ipv6+0x12e/0x680 net/bridge/br_netfilter_ipv6.c:225
 nf_hook_entry_hookfn include/linux/netfilter.h:142 [inline]
 nf_hook_bridge_pre net/bridge/br_input.c:242 [inline]
 br_handle_frame+0x893/0x1190 net/bridge/br_input.c:384
 __netif_receive_skb_core+0xfef/0x3690 net/core/dev.c:5419
 __netif_receive_skb_one_core net/core/dev.c:5523 [inline]
 __netif_receive_skb+0x74/0x290 net/core/dev.c:5639
 process_backlog+0x370/0x790 net/core/dev.c:6516
 __napi_poll+0xc0/0x430 net/core/dev.c:7075
 napi_poll net/core/dev.c:7142 [inline]
 net_rx_action+0x4d4/0xa10 net/core/dev.c:7232
 handle_softirqs+0x339/0x830 kernel/softirq.c:576
 __do_softirq kernel/softirq.c:610 [inline]
 invoke_softirq kernel/softirq.c:450 [inline]
 __irq_exit_rcu+0x13b/0x230 kernel/softirq.c:659
 irq_exit_rcu+0x5/0x20 kernel/softirq.c:671
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1108 [inline]
 sysvec_apic_timer_interrupt+0xa0/0xc0 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:finish_lock_switch+0x134/0x280 kernel/sched/core.c:4804
Code: be ff ff ff ff e8 4c 80 67 08 85 c0 74 4a 4d 85 ff 75 66 0f 1f 44 00 00 48 89 df e8 b6 eb 70 08 e8 41 e0 2a 00 fb 48 83 c4 08 <5b> 41 5c 41 5d 41 5e 41 5f 5d c3 48 89 df e8 c9 09 fe ff 43 80 3c
RSP: 0018:ffffc900035ef248 EFLAGS: 00000286
RAX: 88728bb57a913a00 RBX: ffff8880b903a340 RCX: 88728bb57a913a00
RDX: dffffc0000000000 RSI: ffffffff8a2b2780 RDI: ffffffff8a79f780
RBP: 1ffff11017207613 R08: ffffffff901d10cf R09: 1ffffffff203a219
R10: dffffc0000000000 R11: fffffbfff203a21a R12: 1ffff110172075c1
R13: dffffc0000000000 R14: ffff8880b903ae08 R15: 0000000000000000
 finish_task_switch+0x12f/0x640 kernel/sched/core.c:4921
 context_switch kernel/sched/core.c:5052 [inline]
 __schedule+0x11f7/0x43c0 kernel/sched/core.c:6395
 preempt_schedule_irq+0xbb/0x160 kernel/sched/core.c:6799
 irqentry_exit+0x63/0x70 kernel/entry/common.c:432
 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:676
RIP: 0010:lock_acquire+0x208/0x400 kernel/locking/lockdep.c:5627
Code: f7 84 24 80 00 00 00 00 02 00 00 43 c6 44 3d 04 f8 0f 85 f1 00 00 00 41 f7 c6 00 02 00 00 74 01 fb 48 c7 44 24 60 0e 36 e0 45 <4b> c7 44 3d 00 00 00 00 00 43 c7 44 3d 08 00 00 00 00 65 48 8b 04
RSP: 0018:ffffc900035ef620 EFLAGS: 00000206
RAX: 0000000000000001 RBX: 0000000000000000 RCX: 88728bb57a913a00
RDX: 0000000000000000 RSI: ffffffff8a2b3a20 RDI: ffffffff8a79f780
RBP: ffffc900035ef740 R08: dffffc0000000000 R09: 1ffffffff203a218
R10: dffffc0000000000 R11: fffffbfff203a219 R12: ffffffff8c31eaa0
R13: 1ffff920006bded0 R14: 0000000000000246 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: 0033:0x7fd2f537beb9
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:00007fd2f35d6fd8 EFLAGS: 00000206 ORIG_RAX: 0000000000000038
RAX: ffffffffffffffda RBX: 00007fd2f55f6fa0 RCX: 00007fd2f537beb9
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 00000000400c0000
RBP: 00007fd2f53e9c1f R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000000
R13: 00007fd2f55f7038 R14: 00007fd2f55f6fa0 R15: 00007ffffba9b118
 </TASK>