INFO: task kworker/u8:5:9458 blocked for more than 122 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/u8:5 state:D stack:0 pid:9458 tgid:9458 ppid:2 flags:0x00004000
Workqueue: events_unbound linkwatch_event
Call Trace:
context_switch kernel/sched/core.c:5945 [inline]
__schedule+0x1322/0x1df0 kernel/sched/core.c:7791
__schedule_loop kernel/sched/core.c:7872 [inline]
schedule+0xc6/0x240 kernel/sched/core.c:7887
schedule_preempt_disabled+0x14/0x30 kernel/sched/core.c:7944
__mutex_lock_common kernel/locking/mutex.c:707 [inline]
__mutex_lock+0x81e/0x1b50 kernel/locking/mutex.c:803
__mutex_lock_slowpath+0xe/0x20 kernel/locking/mutex.c:1134
mutex_lock+0x102/0x1c0 kernel/locking/mutex.c:285
rtnl_lock+0x19/0x20 net/core/rtnetlink.c:79
linkwatch_event+0x12/0x60 net/core/link_watch.c:285
process_one_work kernel/workqueue.c:3238 [inline]
process_scheduled_works+0x7d5/0x1020 kernel/workqueue.c:3319
worker_thread+0xc58/0x1250 kernel/workqueue.c:3400
kthread+0x2c7/0x370 kernel/kthread.c:389
ret_from_fork+0x67/0xa0 arch/x86/kernel/process.c:153
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 37 Comm: khungtaskd Not tainted syzkaller #0 530b3ddaa03db34d09c0fae50fba32de8d319ece
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
Call Trace:
__dump_stack+0x21/0x30 lib/dump_stack.c:94
dump_stack_lvl+0x10c/0x190 lib/dump_stack.c:120
dump_stack+0x19/0x20 lib/dump_stack.c:129
nmi_cpu_backtrace+0x2bf/0x2d0 lib/nmi_backtrace.c:113
nmi_trigger_cpumask_backtrace+0x142/0x2c0 lib/nmi_backtrace.c:62
arch_trigger_cpumask_backtrace+0x14/0x20 arch/x86/kernel/apic/hw_nmi.c:41
trigger_all_cpu_backtrace include/linux/nmi.h:158 [inline]
check_hung_uninterruptible_tasks kernel/hung_task.c:267 [inline]
watchdog+0xd8f/0xed0 kernel/hung_task.c:423
kthread+0x2c7/0x370 kernel/kthread.c:389
ret_from_fork+0x67/0xa0 arch/x86/kernel/process.c:153
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 201 Comm: sshd Not tainted syzkaller #0 530b3ddaa03db34d09c0fae50fba32de8d319ece
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
RIP: 0010:update_stack_state+0x41e/0x4b0 arch/x86/kernel/unwind_frame.c:257
Code: 80 3c 20 00 74 08 48 89 df e8 1e e5 97 00 4c 89 33 43 80 3c 27 00 4c 8b 75 b8 74 08 4c 89 f7 e8 e8 e3 97 00 b3 01 49 83 3e 00 <0f> 85 80 fe ff ff 43 80 3c 27 00 74 08 4c 89 f7 e8 ed e4 97 00 48
RSP: 0018:ffffc900002300f8 EFLAGS: 00000282
RAX: 1ffff92000046052 RBX: ffffc90000230201 RCX: ffffc90000f4ff01
RDX: ffffc90000f4ff20 RSI: 1ffff9200004604a RDI: ffffc900002302a0
RBP: ffffc900002301b8 R08: ffffc90000230310 R09: ffffc90000230308
R10: 0000000000000014 R11: ffffffff81744340 R12: dffffc0000000000
R13: ffffc90000230270 R14: ffffc90000230288 R15: 1ffff92000046051
FS: 00007f372b55b300(0000) GS:ffff8881f6f00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055d585c4db90 CR3: 0000000120884000 CR4: 00000000003526b0
Call Trace:
unwind_next_frame+0x3c2/0x750 arch/x86/kernel/unwind_frame.c:315
arch_stack_walk+0x139/0x170 arch/x86/kernel/stacktrace.c:25
stack_trace_save+0x9d/0xe0 kernel/stacktrace.c:122
kasan_save_stack mm/kasan/common.c:47 [inline]
kasan_save_track+0x3e/0x80 mm/kasan/common.c:68
kasan_save_alloc_info+0x40/0x50 mm/kasan/generic.c:565
unpoison_slab_object mm/kasan/common.c:319 [inline]
__kasan_slab_alloc+0x73/0x90 mm/kasan/common.c:345
kasan_slab_alloc include/linux/kasan.h:250 [inline]
slab_post_alloc_hook mm/slub.c:4169 [inline]
slab_alloc_node mm/slub.c:4218 [inline]
kmem_cache_alloc_noprof+0x131/0x3a0 mm/slub.c:4227
skb_clone+0x229/0x460 net/core/skbuff.c:2082
deliver_clone net/bridge/br_forward.c:125 [inline]
maybe_deliver net/bridge/br_forward.c:190 [inline]
br_flood+0x4ed/0x730 net/bridge/br_forward.c:236
br_handle_frame_finish+0x12bb/0x1720 net/bridge/br_input.c:215
nf_hook_bridge_pre net/bridge/br_input.c:301 [inline]
br_handle_frame+0x5a6/0xba0 net/bridge/br_input.c:424
__netif_receive_skb_core+0xf48/0x3940 net/core/dev.c:5651
__netif_receive_skb_one_core net/core/dev.c:5755 [inline]
__netif_receive_skb net/core/dev.c:5870 [inline]
process_backlog+0x3e5/0xae0 net/core/dev.c:6206
__napi_poll+0xd0/0x610 net/core/dev.c:6857
napi_poll net/core/dev.c:6926 [inline]
net_rx_action+0x584/0xce0 net/core/dev.c:7048
handle_softirqs+0x1ab/0x630 kernel/softirq.c:621
__do_softirq+0xf/0x16 kernel/softirq.c:659
do_softirq+0xa6/0x100 kernel/softirq.c:503
__local_bh_enable_ip+0x74/0x80 kernel/softirq.c:430
local_bh_enable include/linux/bottom_half.h:33 [inline]
fpregs_unlock arch/x86/include/asm/fpu/api.h:80 [inline]
copy_fpstate_to_sigframe+0x487/0xb80 arch/x86/kernel/fpu/signal.c:225
get_sigframe+0x58e/0x7d0 arch/x86/kernel/signal.c:163
x64_setup_rt_frame+0x15d/0xcc0 arch/x86/kernel/signal_64.c:175
setup_rt_frame arch/x86/kernel/signal.c:250 [inline]
handle_signal arch/x86/kernel/signal.c:294 [inline]
arch_do_signal_or_restart+0x31d/0x720 arch/x86/kernel/signal.c:339
exit_to_user_mode_loop kernel/entry/common.c:111 [inline]
exit_to_user_mode_prepare include/linux/entry-common.h:328 [inline]
__syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline]
syscall_exit_to_user_mode+0x58/0xb0 kernel/entry/common.c:218
do_syscall_64+0x64/0xf0 arch/x86/entry/common.c:89
entry_SYSCALL_64_after_hwframe+0x76/0x7e
RIP: 0033:0x7f372aea7407
Code: 48 89 fa 4c 89 df e8 38 aa 00 00 8b 93 08 03 00 00 59 5e 48 83 f8 fc 74 1a 5b c3 0f 1f 84 00 00 00 00 00 48 8b 44 24 10 0f 05 <5b> c3 0f 1f 80 00 00 00 00 83 e2 39 83 fa 08 75 de e8 23 ff ff ff
RSP: 002b:00007ffc6bfd74c0 EFLAGS: 00000202 ORIG_RAX: 000000000000010f
RAX: fffffffffffffffc RBX: 00007f372b55b300 RCX: 00007f372aea7407
RDX: 0000000000000000 RSI: 0000000000000002 RDI: 000055bc42645400
RBP: 0000000000000002 R08: 0000000000000008 R09: 0000000000000000
R10: 00007ffc6bfd7790 R11: 0000000000000202 R12: 0000000000000064
R13: 0000000000000000 R14: 000055bc293a9004 R15: 0000000000000002
net_ratelimit: 114119 callbacks suppressed
bridge0: received packet on veth0_to_bridge with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0)
bridge0: received packet on bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:1b, vlan:0)
bridge0: received packet on veth0_to_bridge with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0)
bridge0: received packet on bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:1b, vlan:0)
bridge0: received packet on bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0)
bridge0: received packet on bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:1b, vlan:0)
bridge0: received packet on veth0_to_bridge with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0)
bridge0: received packet on veth0_to_bridge with own address as source address (addr:1e:14:fb:b4:1a:32, vlan:0)
bridge0: received packet on bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0)
bridge0: received packet on veth0_to_bridge with own address as source address (addr:1e:14:fb:b4:1a:32, vlan:0)