INFO: task kworker/u8:4:330 blocked for more than 122 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/u8:4 state:D stack:0 pid:330 tgid:330 ppid:2 flags:0x00004000
Workqueue: netns cleanup_net
Call Trace:
context_switch kernel/sched/core.c:6016 [inline]
__schedule+0x134f/0x1ea0 kernel/sched/core.c:7864
__schedule_loop kernel/sched/core.c:7945 [inline]
schedule+0xc5/0x240 kernel/sched/core.c:7960
schedule_preempt_disabled+0x14/0x30 kernel/sched/core.c:8017
__mutex_lock_common kernel/locking/mutex.c:707 [inline]
__mutex_lock+0x960/0x1bb0 kernel/locking/mutex.c:803
__mutex_lock_slowpath+0xe/0x20 kernel/locking/mutex.c:1134
mutex_lock+0x113/0x1d0 kernel/locking/mutex.c:285
rcu_barrier+0x4d/0x540 kernel/rcu/tree.c:4589
netdev_run_todo+0x118/0xce0 net/core/dev.c:10887
rtnl_unlock+0x12/0x20 net/core/rtnetlink.c:152
cleanup_net+0x648/0xc90 net/core/net_namespace.c:638
process_one_work kernel/workqueue.c:3238 [inline]
process_scheduled_works+0x7d4/0x1020 kernel/workqueue.c:3319
worker_thread+0xc70/0x10b0 kernel/workqueue.c:3400
kthread+0x2c9/0x370 kernel/kthread.c:389
ret_from_fork+0x64/0xa0 arch/x86/kernel/process.c:153
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
INFO: task syz.3.316:1398 blocked for more than 128 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.3.316 state:D stack:0 pid:1398 tgid:1397 ppid:294 flags:0x00004002
Call Trace:
context_switch kernel/sched/core.c:6016 [inline]
__schedule+0x134f/0x1ea0 kernel/sched/core.c:7864
__schedule_loop kernel/sched/core.c:7945 [inline]
schedule+0xc5/0x240 kernel/sched/core.c:7960
schedule_preempt_disabled+0x14/0x30 kernel/sched/core.c:8017
__mutex_lock_common kernel/locking/mutex.c:707 [inline]
__mutex_lock+0x960/0x1bb0 kernel/locking/mutex.c:803
__mutex_lock_slowpath+0xe/0x20 kernel/locking/mutex.c:1134
mutex_lock+0x113/0x1d0 kernel/locking/mutex.c:285
exp_funnel_lock kernel/rcu/tree_exp.h:331 [inline]
synchronize_rcu_expedited+0x296/0x970 kernel/rcu/tree_exp.h:978
namespace_unlock+0x248/0x430 fs/namespace.c:1710
drop_collected_mounts fs/namespace.c:2238 [inline]
put_mnt_ns+0xad/0xf0 fs/namespace.c:5645
free_nsproxy+0x52/0x290 kernel/nsproxy.c:193
put_nsproxy include/linux/nsproxy.h:118 [inline]
switch_task_namespaces kernel/nsproxy.c:251 [inline]
exit_task_namespaces+0x99/0xe0 kernel/nsproxy.c:256
do_exit+0x9de/0x2650 kernel/exit.c:952
do_group_exit+0x229/0x2f0 kernel/exit.c:1095
get_signal+0x1398/0x14e0 kernel/signal.c:2933
arch_do_signal_or_restart+0xbc/0x760 arch/x86/kernel/signal.c:337
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+0x57/0xb0 kernel/entry/common.c:218
do_syscall_64+0x63/0xf0 arch/x86/entry/common.c:84
entry_SYSCALL_64_after_hwframe+0x76/0x7e
RIP: 0033:0x7ff33779c799
RSP: 002b:00007ff3385c00e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca
RAX: 0000000000000001 RBX: 00007ff337a15fa8 RCX: 00007ff33779c799
RDX: 00000000000f4240 RSI: 0000000000000081 RDI: 00007ff337a15fac
RBP: 00007ff337a15fa0 R08: 7fffffffffffffff R09: 0000000000000000
R10: ffffffffffffffff R11: 0000000000000246 R12: 0000000000000000
R13: 00007ff337a16038 R14: 00007ffee9c91ee0 R15: 00007ffee9c91fc8
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 37 Comm: khungtaskd Not tainted syzkaller #0 93fdfe3663caa6d824c2578ca6c3b1aacfeda3e9
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
Call Trace:
__dump_stack+0x21/0x30 lib/dump_stack.c:94
dump_stack_lvl+0x140/0x1c0 lib/dump_stack.c:120
dump_stack+0x19/0x20 lib/dump_stack.c:129
nmi_cpu_backtrace+0x2ba/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+0xdad/0xf00 kernel/hung_task.c:423
kthread+0x2c9/0x370 kernel/kthread.c:389
ret_from_fork+0x64/0xa0 arch/x86/kernel/process.c:153
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 9 Comm: kworker/0:0 Not tainted syzkaller #0 93fdfe3663caa6d824c2578ca6c3b1aacfeda3e9
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
Workqueue: wg-crypt-wg2 wg_packet_decrypt_worker
RIP: 0010:ipv6_addr_equal include/net/ipv6.h:664 [inline]
RIP: 0010:ipv6_chk_mcast_addr+0xd8/0x3e0 net/ipv6/mcast.c:1025
Code: 8b 3c 24 49 83 c4 08 4c 89 e0 48 c1 e8 03 48 b9 00 00 00 00 00 fc ff df 80 3c 08 00 74 08 4c 89 e7 e8 4c 0e e3 fc 4d 8b 24 24 <48> 89 d8 48 c1 e8 03 48 b9 00 00 00 00 00 fc ff df 80 3c 08 00 74
RSP: 0018:ffffc900000073d8 EFLAGS: 00000246
RAX: 1ffff11022cabe26 RBX: ffff888130b93c00 RCX: dffffc0000000000
RDX: 0000000000000100 RSI: ffff88811655f128 RDI: ffff888103b54000
RBP: ffffc90000007410 R08: 0000000000000000 R09: ffff888154821780
R10: 0000000000000000 R11: ffffffff84f13cd0 R12: 0200000000000000
R13: ffff88811655f128 R14: dffffc0000000000 R15: 00000000000002ff
FS: 0000000000000000(0000) GS:ffff8881f6e00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007ffe4cd89fbc CR3: 000000010afbe000 CR4: 00000000003526b0
Call Trace:
ip6_mc_input+0x255/0x6c0 net/ipv6/ip6_input.c:521
dst_input include/net/dst.h:469 [inline]
ip6_rcv_finish+0x360/0x3e0 net/ipv6/ip6_input.c:79
NF_HOOK include/linux/netfilter.h:317 [inline]
ipv6_rcv+0xf1/0x240 net/ipv6/ip6_input.c:309
__netif_receive_skb_one_core net/core/dev.c:5776 [inline]
__netif_receive_skb net/core/dev.c:5889 [inline]
netif_receive_skb_internal net/core/dev.c:5975 [inline]
netif_receive_skb+0x147/0x7b0 net/core/dev.c:6034
br_netif_receive_skb net/bridge/br_input.c:30 [inline]
NF_HOOK include/linux/netfilter.h:317 [inline]
br_pass_frame_up+0x126/0x1b0 net/bridge/br_input.c:70
br_handle_frame_finish+0x1317/0x1760 net/bridge/br_input.c:221
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+0xfae/0x3ab0 net/core/dev.c:5670
__netif_receive_skb_one_core net/core/dev.c:5774 [inline]
__netif_receive_skb net/core/dev.c:5889 [inline]
process_backlog+0x3e5/0xad0 net/core/dev.c:6225
__napi_poll+0xd0/0x610 net/core/dev.c:6876
napi_poll net/core/dev.c:6945 [inline]
net_rx_action+0x5ea/0xd80 net/core/dev.c:7067
handle_softirqs+0x1aa/0x630 kernel/softirq.c:621
__do_softirq+0xf/0x16 kernel/softirq.c:659
do_softirq+0xb8/0x110 kernel/softirq.c:503
__local_bh_enable_ip+0x74/0x80 kernel/softirq.c:430
__raw_spin_unlock_bh include/linux/spinlock_api_smp.h:167 [inline]
_raw_spin_unlock_bh+0x54/0x60 kernel/locking/spinlock.c:210
spin_unlock_bh include/linux/spinlock.h:396 [inline]
ptr_ring_consume_bh include/linux/ptr_ring.h:367 [inline]
wg_packet_decrypt_worker+0xcde/0xd50 drivers/net/wireguard/receive.c:499
process_one_work kernel/workqueue.c:3238 [inline]
process_scheduled_works+0x7d4/0x1020 kernel/workqueue.c:3319
worker_thread+0xc70/0x10b0 kernel/workqueue.c:3400
kthread+0x2c9/0x370 kernel/kthread.c:389
ret_from_fork+0x64/0xa0 arch/x86/kernel/process.c:153
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244