INFO: task kworker/u8:23:550 blocked for more than 123 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/u8:23 state:D stack:0 pid:550 tgid:550 ppid:2 flags:0x00004000
Workqueue: netns cleanup_net
Call Trace:
context_switch kernel/sched/core.c:6060 [inline]
__schedule+0x1496/0x20b0 kernel/sched/core.c:7873
__schedule_loop kernel/sched/core.c:7950 [inline]
schedule+0xc5/0x240 kernel/sched/core.c:7965
schedule_timeout+0xc7/0x3b0 kernel/time/timer.c:2596
do_wait_for_common kernel/sched/completion.c:95 [inline]
__wait_for_common kernel/sched/completion.c:116 [inline]
wait_for_common+0x368/0x650 kernel/sched/completion.c:127
wait_for_completion+0x1c/0x40 kernel/sched/completion.c:148
rcu_barrier+0x45a/0x580 kernel/rcu/tree.c:4657
netdev_run_todo+0x118/0xce0 net/core/dev.c:10912
rtnl_unlock+0x12/0x20 net/core/rtnetlink.c:152
cleanup_net+0x645/0xc90 net/core/net_namespace.c:638
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
INFO: task syz.1.1444:5082 blocked for more than 124 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.1.1444 state:D stack:0 pid:5082 tgid:5081 ppid:294 flags:0x00004006
Call Trace:
context_switch kernel/sched/core.c:6060 [inline]
__schedule+0x1496/0x20b0 kernel/sched/core.c:7873
__schedule_loop kernel/sched/core.c:7950 [inline]
schedule+0xc5/0x240 kernel/sched/core.c:7965
schedule_preempt_disabled+0x14/0x30 kernel/sched/core.c:8022
__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
rcu_barrier+0x4d/0x580 kernel/rcu/tree.c:4589
netdev_run_todo+0x118/0xce0 net/core/dev.c:10912
rtnl_unlock+0x12/0x20 net/core/rtnetlink.c:152
tun_detach drivers/net/tun.c:704 [inline]
tun_chr_close+0xc5/0x150 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: 0033:0x7fc90ad9de99
RSP: 002b:00007fc90bcf1028 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: fffffffffffffff4 RBX: 00007fc90b025fa0 RCX: 00007fc90ad9de99
RDX: 0000000000000000 RSI: 00002000000000c0 RDI: 0000200000000040
RBP: 00007fc90ae33eaf R08: 0000000000000000 R09: 0000000000000000
R10: 0000000002a05404 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fc90b026038 R14: 00007fc90b025fa0 R15: 00007ffd5100e258
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 37 Comm: khungtaskd Not tainted syzkaller #0 0d2653c4e30e8393174ae36c9890472a2669fe52
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/16/2026
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 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 20 Comm: rcuop/0 Not tainted syzkaller #0 0d2653c4e30e8393174ae36c9890472a2669fe52
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/16/2026
RIP: 0010:find_match+0x176/0x10d0 net/ipv6/route.c:786
Code: 5d 41 5e 41 5f 5d c3 cc cc cc cc cc e8 13 8c 8b fc eb 05 e8 0c 8c 8b fc 48 8b 7d d0 44 89 e6 8b 55 b0 44 89 f1 e8 5a e4 fd ff <41> 89 c7 bf ff ff ff ff 89 c6 e8 2b 90 8b fc 41 83 ff ff 74 1a bf
RSP: 0018:ffffc90000230210 EFLAGS: 00000286
RAX: 00000000fffffffd RBX: 0000000000000000 RCX: ffff888103663900
RDX: 0000000000000100 RSI: 0000000000000001 RDI: 0000000000000000
RBP: ffffc900002302d0 R08: ffffc90000230540 R09: ffffc90000230550
R10: ffffc900002306b0 R11: fffff520000460da R12: 0000000000000001
R13: 1ffff110259c0798 R14: 0000000000000003 R15: 0000000000000000
FS: 0000000000000000(0000) GS:ffff8881f6f00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fc8c9025f40 CR3: 000000010c7a4000 CR4: 00000000003526b0
Call Trace:
__find_rr_leaf+0x249/0x840 net/ipv6/route.c:869
find_rr_leaf net/ipv6/route.c:890 [inline]
rt6_select net/ipv6/route.c:934 [inline]
fib6_table_lookup+0x2d0/0x980 net/ipv6/route.c:2242
ip6_pol_route+0x17a/0x1370 net/ipv6/route.c:2278
ip6_pol_route_input+0x5a/0x80 net/ipv6/route.c:2335
pol_lookup_func include/net/ip6_fib.h:647 [inline]
fib6_rule_lookup+0x4f1/0x6d0 net/ipv6/fib6_rules.c:117
ip6_route_input_lookup net/ipv6/route.c:2347 [inline]
ip6_route_input+0x60d/0x8d0 net/ipv6/route.c:2643
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+0xd0/0x600 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
local_bh_enable include/linux/bottom_half.h:33 [inline]
rcu_do_batch+0x590/0xcb0 kernel/rcu/tree.c:2594
nocb_cb_wait kernel/rcu/tree_nocb.h:923 [inline]
rcu_nocb_cb_kthread+0x533/0xb60 kernel/rcu/tree_nocb.h:957
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: 132064 callbacks suppressed
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:0c, vlan:0)
bridge0: received packet on veth0_to_bridge with own address as source address (addr:36:3b:65:4f:87:ce, 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: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:36:3b:65:4f:87:ce, 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:0c, vlan:0)