INFO: task kworker/u8:0:12 blocked for more than 122 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/u8:0    state:D stack:0     pid:12    tgid:12    ppid:2      flags:0x00004000
Workqueue: ipv6_addrconf addrconf_verify_work
Call Trace:
 <TASK>
 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
 addrconf_verify_work+0x1d/0x50 net/ipv6/addrconf.c:4774
 process_one_work kernel/workqueue.c:3238 [inline]
 process_scheduled_works+0x7d2/0x1020 kernel/workqueue.c:3319
 worker_thread+0xc58/0x1250 kernel/workqueue.c:3400
 kthread+0x2ca/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
 </TASK>
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 37 Comm: khungtaskd Not tainted syzkaller #0 13e4930ead2c4bb99e6e1e727baa5d081f82ad96
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025
Call Trace:
 <TASK>
 __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+0x2ca/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
 </TASK>
Sending NMI from CPU 1 to CPUs 0:
net_ratelimit: 36804 callbacks suppressed
bridge0: received packet on veth1_to_bridge with own address as source address (addr:00:00:00:00:67:5f, vlan:0)
bridge0: received packet on veth1_to_bridge with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0)
bridge0: received packet on veth1_to_bridge with own address as source address (addr:fe:7d:ba:ef:0d:54, vlan:0)
bridge0: received packet on bridge_slave_1 with own address as source address (addr:aa:aa:aa:aa:aa:1c, vlan:0)
bridge0: received packet on veth1_to_bridge with own address as source address (addr:fe:7d:ba:ef:0d:54, vlan:0)
bridge0: received packet on bridge_slave_1 with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0)
bridge0: received packet on bridge_slave_1 with own address as source address (addr:00:00:00:00:67:5f, vlan:0)
bridge0: received packet on veth1_to_bridge with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0)
bridge0: received packet on veth1_to_bridge with own address as source address (addr:00:00:00:00:67:5f, vlan:0)
bridge0: received packet on bridge_slave_1 with own address as source address (addr:aa:aa:aa:aa:aa:1c, vlan:0)
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 20 Comm: rcuop/0 Not tainted syzkaller #0 13e4930ead2c4bb99e6e1e727baa5d081f82ad96
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025
RIP: 0010:__sanitizer_cov_trace_pc+0x5/0x70 kernel/kcov.c:210
Code: e8 10 5f 52 00 5b 5d e9 c9 9c 09 04 cc cc cc cc cc cc cc cc cc b8 2b c3 4b 29 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 55 <48> 89 e5 48 8b 45 08 65 48 8b 0c 25 00 eb 04 00 65 8b 15 3c ec 7e
RSP: 0018:ffffc90000006c50 EFLAGS: 00000286
RAX: 7389eec558e7a000 RBX: 0000000000000100 RCX: ffff888103662600
RDX: 0000000000000100 RSI: ffff888131ff8c00 RDI: ffff888131ff8c00
RBP: ffffc90000006dd0 R08: ffffc90000006d38 R09: 000000000000000d
R10: ffffc90000006ed0 R11: fffff52000000dde R12: ffff88812c3bdb80
R13: 1ffff92000000ddb R14: ffffc90000006ed8 R15: dffffc0000000000
FS:  0000000000000000(0000) GS:ffff8881f6e00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000557811a0bb98 CR3: 000000010bfce000 CR4: 00000000003526b0
Call Trace:
 <IRQ>
 ip6_pol_route+0x167/0x12c0 net/ipv6/route.c:2266
 ip6_pol_route_input+0x5a/0x80 net/ipv6/route.c:2323
 pol_lookup_func include/net/ip6_fib.h:626 [inline]
 __fib6_rule_action net/ipv6/fib6_rules.c:234 [inline]
 fib6_rule_action+0x9bc/0xbc0 net/ipv6/fib6_rules.c:272
 fib_rules_lookup+0x4b4/0xa30 net/core/fib_rules.c:320
 fib6_rule_lookup+0x171/0x6b0 net/ipv6/fib6_rules.c:109
 ip6_route_input_lookup net/ipv6/route.c:2335 [inline]
 ip6_route_input+0x59f/0x8d0 net/ipv6/route.c:2631
 ip6_rcv_finish_core net/ipv6/ip6_input.c:66 [inline]
 ip6_rcv_finish+0x15a/0x3e0 net/ipv6/ip6_input.c:77
 NF_HOOK include/linux/netfilter.h:317 [inline]
 ipv6_rcv+0xed/0x220 net/ipv6/ip6_input.c:309
 __netif_receive_skb_one_core net/core/dev.c:5769 [inline]
 __netif_receive_skb net/core/dev.c:5882 [inline]
 netif_receive_skb_internal net/core/dev.c:5968 [inline]
 netif_receive_skb+0x147/0x7b0 net/core/dev.c:6027
 br_netif_receive_skb net/bridge/br_input.c:30 [inline]
 NF_HOOK include/linux/netfilter.h:317 [inline]
 br_pass_frame_up+0x126/0x1c0 net/bridge/br_input.c:70
 br_handle_frame_finish+0x12d9/0x1720 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+0xf4b/0x3940 net/core/dev.c:5663
 __netif_receive_skb_one_core net/core/dev.c:5767 [inline]
 __netif_receive_skb net/core/dev.c:5882 [inline]
 process_backlog+0x3e5/0xae0 net/core/dev.c:6218
 __napi_poll+0xd3/0x610 net/core/dev.c:6869
 napi_poll net/core/dev.c:6938 [inline]
 net_rx_action+0x584/0xce0 net/core/dev.c:7060
 handle_softirqs+0x1ab/0x630 kernel/softirq.c:621
 __do_softirq+0xf/0x16 kernel/softirq.c:659
 do_softirq+0xa6/0x100 kernel/softirq.c:503
 </IRQ>
 <TASK>
 __local_bh_enable_ip+0x74/0x80 kernel/softirq.c:430
 local_bh_enable include/linux/bottom_half.h:33 [inline]
 rcu_do_batch+0x5c6/0xd20 kernel/rcu/tree.c:2594
 nocb_cb_wait kernel/rcu/tree_nocb.h:923 [inline]
 rcu_nocb_cb_kthread+0x4dc/0xac0 kernel/rcu/tree_nocb.h:957
 kthread+0x2ca/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
 </TASK>
net_ratelimit: 35036 callbacks suppressed
bridge0: received packet on veth1_to_bridge with own address as source address (addr:00:00:00:00:67:5f, vlan:0)
bridge0: received packet on bridge_slave_1 with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0)
bridge0: received packet on veth1_to_bridge with own address as source address (addr:fe:7d:ba:ef:0d:54, vlan:0)
bridge0: received packet on veth1_to_bridge with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0)
bridge0: received packet on bridge_slave_1 with own address as source address (addr:aa:aa:aa:aa:aa:1c, vlan:0)
bridge0: received packet on bridge_slave_1 with own address as source address (addr:aa:aa:aa:aa:aa:1c, vlan:0)
bridge0: received packet on veth1_to_bridge with own address as source address (addr:fe:7d:ba:ef:0d:54, vlan:0)
bridge0: received packet on bridge_slave_1 with own address as source address (addr:aa:aa:aa:aa:aa:1c, vlan:0)
bridge0: received packet on bridge_slave_1 with own address as source address (addr:00:00:00:00:67:5f, vlan:0)
bridge0: received packet on veth1_to_bridge with own address as source address (addr:b6:6a:a3:20:7b:81, vlan:0)