INFO: task syz-executor:434 blocked for more than 122 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor state:D stack:0 pid:434 tgid:434 ppid:1 flags:0x00004006
Call Trace:
context_switch kernel/sched/core.c:6060 [inline]
__schedule+0x1496/0x20b0 kernel/sched/core.c:7880
__schedule_loop kernel/sched/core.c:7957 [inline]
schedule+0xc5/0x240 kernel/sched/core.c:7972
schedule_preempt_disabled+0x14/0x30 kernel/sched/core.c:8029
__mutex_lock_common kernel/locking/mutex.c:707 [inline]
__mutex_lock+0x902/0x1b90 kernel/locking/mutex.c:806
__mutex_lock_slowpath+0xe/0x20 kernel/locking/mutex.c:1136
mutex_lock+0x113/0x1d0 kernel/locking/mutex.c:285
rtnl_lock+0x19/0x20 net/core/rtnetlink.c:79
tun_detach drivers/net/tun.c:698 [inline]
tun_chr_close+0x41/0x150 drivers/net/tun.c:3520
__fput+0x208/0xa30 fs/file_table.c:447
____fput+0x20/0x30 fs/file_table.c:475
task_work_run+0x1e8/0x260 kernel/task_work.c:246
exit_task_work include/linux/task_work.h:43 [inline]
do_exit+0xa46/0x2850 kernel/exit.c:955
do_group_exit+0x21f/0x2f0 kernel/exit.c:1098
get_signal+0x134c/0x1490 kernel/signal.c:2933
arch_do_signal_or_restart+0xbc/0x700 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: 0033:0x7f716c759257
RSP: 002b:00007ffebbd876c0 EFLAGS: 00000202 ORIG_RAX: 000000000000002c
RAX: 0000000000000028 RBX: 000055558b089500 RCX: 00007f716c759257
RDX: 0000000000000028 RSI: 00007f716d554670 RDI: 0000000000000003
RBP: 0000000000000001 R08: 00007ffebbd87724 R09: 000000000000000c
R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000003
R13: 0000000000000000 R14: 00007f716d554670 R15: 0000000000000000
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 37 Comm: khungtaskd Not tainted syzkaller #0 c4896d72d1fb51cdc6291d08376a37fd8080d7bb
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
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+0xe45/0xf90 kernel/hung_task.c:423
kthread+0x2c7/0x360 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 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 379 Comm: kworker/u8:20 Not tainted syzkaller #0 c4896d72d1fb51cdc6291d08376a37fd8080d7bb
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
Workqueue: netns cleanup_net
RIP: 0010:__siphash_unaligned+0x13c/0x3c0 lib/siphash.c:88
Code: f8 48 c1 e8 03 0f b6 04 10 84 c0 0f 85 cb 00 00 00 4d 01 f4 49 c1 c6 0d 48 8b 45 c8 4a 8b 04 00 4d 31 e6 49 c1 c4 20 48 31 c3 <49> 01 df 48 c1 c3 10 4c 31 fb 49 01 dc 48 c1 c3 15 4d 01 f7 49 c1
RSP: 0018:ffffc90000007368 EFLAGS: 00000286
RAX: 0000000000000000 RBX: bf7ae5ee2c5dac7b RCX: ffff8881143d1300
RDX: dffffc0000000000 RSI: 0000000000000040 RDI: ffffc90000007777
RBP: ffffc900000073c0 R08: 0000000000000018 R09: ffffc90000007770
R10: 0000000000000008 R11: 0000000000000100 R12: 2eebacd8bd59b37e
R13: 0000000000000010 R14: 2cbb4579d87a848b R15: 8d83dcb2ccc9f8ee
FS: 0000000000000000(0000) GS:ffff8881f6e00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000563c6f90daf8 CR3: 000000010c722000 CR4: 00000000003526b0
Call Trace:
siphash include/linux/siphash.h:86 [inline]
__flow_hash_from_keys+0x440/0x6e0 net/core/flow_dissector.c:1803
flow_hash_from_keys+0x83/0x140 net/core/flow_dissector.c:1814
fib_multipath_hash_from_keys include/net/ip_fib.h:556 [inline]
rt6_multipath_hash+0xd9b/0x15b0 net/ipv6/route.c:-1
ip6_route_input+0x739/0x8d0 net/ipv6/route.c:2641
ip6_rcv_finish_core net/ipv6/ip6_input.c:66 [inline]
ip6_rcv_finish+0x15a/0x3c0 net/ipv6/ip6_input.c:77
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:5801 [inline]
__netif_receive_skb net/core/dev.c:5914 [inline]
process_backlog+0x472/0xaf0 net/core/dev.c:6250
__napi_poll+0xcd/0x600 net/core/dev.c:6901
napi_poll net/core/dev.c:6970 [inline]
net_rx_action+0x5dc/0xd70 net/core/dev.c:7092
handle_softirqs+0x1aa/0x620 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]
addrconf_ifdown+0x60d/0x1970 net/ipv6/addrconf.c:3950
addrconf_notify+0x17a/0xeb0 net/ipv6/addrconf.c:-1
notifier_call_chain+0x106/0x2b0 kernel/notifier.c:93
raw_notifier_call_chain+0x31/0x40 kernel/notifier.c:461
call_netdevice_notifiers_info net/core/dev.c:2074 [inline]
call_netdevice_notifiers_extack net/core/dev.c:2112 [inline]
call_netdevice_notifiers net/core/dev.c:2126 [inline]
unregister_netdevice_many_notify+0xde1/0x1be0 net/core/dev.c:11533
unregister_netdevice_many net/core/dev.c:11595 [inline]
default_device_exit_batch+0x845/0x8d0 net/core/dev.c:12166
ops_exit_list net/core/net_namespace.c:178 [inline]
cleanup_net+0x744/0xc90 net/core/net_namespace.c:642
process_one_work kernel/workqueue.c:3273 [inline]
process_scheduled_works+0x7f7/0x1060 kernel/workqueue.c:3354
worker_thread+0xc99/0x13f0 kernel/workqueue.c:3435
kthread+0x2c7/0x360 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
net_ratelimit: 140804 callbacks suppressed
bridge0: received packet on veth0_to_bridge with own address as source address (addr:0a:d0:92:cb:4a:f2, 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:0a:d0:92:cb:4a:f2, 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:0a:d0:92:cb:4a:f2, 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 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)