INFO: task syz.8.3372:19085 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.8.3372 state:D stack:26416 pid:19085 ppid: 15519 flags:0x00004004
Call Trace:
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
tracehook_notify_resume include/linux/tracehook.h:189 [inline]
exit_to_user_mode_loop+0x10f/0x130 kernel/entry/common.c:181
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: 0033:0x7fe7ef336f79
RSP: 002b:00007fe7ed570028 EFLAGS: 00000246 ORIG_RAX: 0000000000000003
RAX: 0000000000000000 RBX: 00007fe7ef5b1090 RCX: 00007fe7ef336f79
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000008
RBP: 00007fe7ef3cd7e0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fe7ef5b1128 R14: 00007fe7ef5b1090 R15: 00007ffed9f4ad78
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
3 locks held by kworker/u4:1/144:
#0: ffff888016c79138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work+0x761/0x1010 kernel/workqueue.c:-1
#1: ffffc900016dfd00 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work+0x79f/0x1010 kernel/workqueue.c:2285
#2: ffffffff8d43c748 (rtnl_mutex){+.+.}-{3:3}, at: linkwatch_event+0xa/0x50 net/core/link_watch.c:251
2 locks held by getty/3945:
#0: ffff88807f0c9098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:252
#1: ffffc900025e62e8 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x5df/0x1a70 drivers/tty/n_tty.c:2158
4 locks held by kworker/u4:5/4266:
#0: ffff888016dcd938 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work+0x761/0x1010 kernel/workqueue.c:-1
#1: ffffc9000340fd00 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work+0x79f/0x1010 kernel/workqueue.c:2285
#2: ffffffff8d430850 (pernet_ops_rwsem){++++}-{3:3}, at: cleanup_net+0x148/0xba0 net/core/net_namespace.c:589
#3: ffffffff8d43c748 (rtnl_mutex){+.+.}-{3:3}, at: netdev_run_todo+0x88f/0xa70 net/core/dev.c:10709
3 locks held by kworker/1:22/5306:
#0: ffff888016c70938 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x761/0x1010 kernel/workqueue.c:-1
#1: ffffc90003a7fd00 ((work_completion)(&(&nsim_dev->trap_data->trap_report_dw)->work)){+.+.}-{0:0}, at: process_one_work+0x79f/0x1010 kernel/workqueue.c:2285
#2: ffff88806162a400 (&nsim_dev->port_list_lock){+.+.}-{3:3}, at: nsim_dev_trap_report_work+0x56/0xb40 drivers/net/netdevsim/dev.c:757
1 lock held by syz.2.2628/15566:
#0: ffffffff8d43c748 (rtnl_mutex){+.+.}-{3:3}, at: netdev_run_todo+0x88f/0xa70 net/core/dev.c:10709
2 locks held by syz.9.3916/22280:
#0: ffffffff8d430850 (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
8 locks held by syz-executor/22412:
#0: ffff88807f2d6460 (sb_writers#8){.+.+}-{0:0}, at: vfs_write+0x295/0xd60 fs/read_write.c:590
#1: ffff88805f857488 (&of->mutex){+.+.}-{3:3}, at: kernfs_fop_write_iter+0x1e5/0x4c0 fs/kernfs/file.c:287
#2: ffff888148007e88 (kn->active#284){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x208/0x4c0 fs/kernfs/file.c:288
#3: ffffffff8cd79c08 (nsim_bus_dev_list_lock){+.+.}-{3:3}, at: del_device_store+0xd3/0x3a0 drivers/net/netdevsim/bus.c:344
#4: ffff8880609dc178 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:764 [inline]
#4: ffff8880609dc178 (&dev->mutex){....}-{3:3}, at: __device_driver_lock drivers/base/dd.c:1044 [inline]
#4: ffff8880609dc178 (&dev->mutex){....}-{3:3}, at: device_release_driver_internal+0xb0/0x750 drivers/base/dd.c:1259
#5: ffff88806162a400 (&nsim_dev->port_list_lock){+.+.}-{3:3}, at: nsim_dev_port_del_all drivers/net/netdevsim/dev.c:1359 [inline]
#5: ffff88806162a400 (&nsim_dev->port_list_lock){+.+.}-{3:3}, at: nsim_dev_reload_destroy+0x115/0x240 drivers/net/netdevsim/dev.c:1561
#6: ffffffff8d43c748 (rtnl_mutex){+.+.}-{3:3}, at: nsim_destroy+0x3b/0x150 drivers/net/netdevsim/netdev.c:381
#7: ffffffff8c323528 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:290 [inline]
#7: ffffffff8c323528 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x2d1/0x750 kernel/rcu/tree_exp.h:845
1 lock held by syz.6.3962/22523:
#0: ffffffff8d43c748 (rtnl_mutex){+.+.}-{3:3}, at: lwtunnel_valid_encap_type+0x31c/0x550 net/core/lwtunnel.c:168
2 locks held by syz.7.3963/22531:
#0: ffffffff8d430850 (pernet_ops_rwsem){++++}-{3:3}, at: copy_net_ns+0x32e/0x5b0 net/core/net_namespace.c:499
#1: ffffffff8d43c748 (rtnl_mutex){+.+.}-{3:3}, at: register_nexthop_notifier+0x84/0x240 net/ipv4/nexthop.c:3620
=============================================
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 02/12/2026
Call Trace:
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
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 13374 Comm: kworker/0:9 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
Workqueue: events nsim_dev_trap_report_work
RIP: 0010:perf_trace_buf_alloc+0x19f/0x300 kernel/trace/trace_event_perf.c:420
Code: 2b 3b 08 89 c5 41 89 c6 bf 08 00 00 00 89 c6 e8 57 28 f8 ff 83 fd 07 0f 87 d0 00 00 00 e8 e9 24 f8 ff 4e 8d 34 f5 20 08 e3 8b <4c> 89 f0 48 c1 e8 03 42 80 3c 28 00 74 08 4c 89 f7 e8 ab 30 3d 00
RSP: 0018:ffffc90000006c60 EFLAGS: 00000046
RAX: ffffffff8180fd57 RBX: 0000000000000014 RCX: ffff88802a533b80
RDX: 0000000000000100 RSI: 0000000000000000 RDI: 0000000000000008
RBP: 0000000000000000 R08: ffff8880b903b30b R09: 1ffff11017207661
R10: dffffc0000000000 R11: ffffed1017207662 R12: ffffffff8be30820
R13: dffffc0000000000 R14: ffffffff8be30820 R15: 0000607f4680b000
FS: 0000000000000000(0000) GS:ffff8880b9000000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f55597c2d71 CR3: 000000005276d000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000200000000300 DR2: 0000200000000300
DR3: 0000200000000300 DR6: 00000000ffff0ff0 DR7: 0000000000000600
Call Trace:
perf_trace_preemptirq_template+0x180/0x360 include/trace/events/preemptirq.h:14
trace_irq_enable_rcuidle+0x108/0x180 include/trace/events/preemptirq.h:40
trace_hardirqs_on+0x57/0x80 kernel/trace/trace_preemptirq.c:44
__free_object+0x218/0xa70 lib/debugobjects.c:358
free_object lib/debugobjects.c:427 [inline]
debug_objects_oom+0x263/0x2f0 lib/debugobjects.c:483
debug_object_activate+0x436/0x4e0 lib/debugobjects.c:699
debug_rcu_head_queue kernel/rcu/rcu.h:176 [inline]
__call_rcu kernel/rcu/tree.c:2995 [inline]
call_rcu+0xa2/0x950 kernel/rcu/tree.c:3091
refdst_drop include/net/dst.h:255 [inline]
skb_dst_drop include/net/dst.h:267 [inline]
skb_release_head_state+0x6d/0x240 net/core/skbuff.c:726
skb_release_all net/core/skbuff.c:740 [inline]
__kfree_skb net/core/skbuff.c:756 [inline]
consume_skb+0x72/0x100 net/core/skbuff.c:914
arp_process+0x150a/0x1ab0 net/ipv4/arp.c:920
NF_HOOK+0x2fe/0x380 include/linux/netfilter.h:302
__netif_receive_skb_one_core net/core/dev.c:5538 [inline]
__netif_receive_skb+0xcc/0x290 net/core/dev.c:5652
netif_receive_skb_internal net/core/dev.c:5738 [inline]
netif_receive_skb+0x19e/0x700 net/core/dev.c:5797
NF_HOOK+0x9b/0x360 include/linux/netfilter.h:302
br_handle_frame_finish+0xfda/0x1270 net/bridge/br_input.c:-1
nf_hook_bridge_pre net/bridge/br_input.c:264 [inline]
br_handle_frame+0x71c/0x10e0 net/bridge/br_input.c:384
__netif_receive_skb_core+0xfef/0x3690 net/core/dev.c:5432
__netif_receive_skb_one_core net/core/dev.c:5536 [inline]
__netif_receive_skb+0x74/0x290 net/core/dev.c:5652
process_backlog+0x370/0x790 net/core/dev.c:6529
__napi_poll+0xc0/0x430 net/core/dev.c:7088
napi_poll net/core/dev.c:7155 [inline]
net_rx_action+0x4d4/0xa10 net/core/dev.c:7245
handle_softirqs+0x339/0x830 kernel/softirq.c:576
do_softirq+0x142/0x210 kernel/softirq.c:477
__local_bh_enable_ip+0x180/0x1c0 kernel/softirq.c:401
spin_unlock_bh include/linux/spinlock.h:409 [inline]
nsim_dev_trap_report drivers/net/netdevsim/dev.c:736 [inline]
nsim_dev_trap_report_work+0x7c0/0xb40 drivers/net/netdevsim/dev.c:762
process_one_work+0x85f/0x1010 kernel/workqueue.c:2310
worker_thread+0xaa6/0x1290 kernel/workqueue.c:2457
kthread+0x436/0x520 kernel/kthread.c:334
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287