INFO: task kworker/u8:2:44 blocked for more than 123 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kworker/u8:2 state:D stack:0 pid:44 tgid:44 ppid:2 flags:0x00004000 Workqueue: netns cleanup_net Call Trace: context_switch kernel/sched/core.c:6026 [inline] __schedule+0x1399/0x1fa0 kernel/sched/core.c:7880 __schedule_loop kernel/sched/core.c:7961 [inline] schedule+0xc5/0x240 kernel/sched/core.c:7976 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+0x369/0x650 kernel/sched/completion.c:127 wait_for_completion+0x1c/0x40 kernel/sched/completion.c:148 rcu_barrier+0x415/0x540 kernel/rcu/tree.c:4657 netdev_run_todo+0x118/0xce0 net/core/dev.c:10900 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:3261 [inline] process_scheduled_works+0x7d4/0x1020 kernel/workqueue.c:3342 worker_thread+0xc51/0x1370 kernel/workqueue.c:3423 kthread+0x2c9/0x370 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 1 CPU: 1 UID: 0 PID: 37 Comm: khungtaskd Not tainted syzkaller #0 0f3775a9ea948f8f8f06e34e337f4a1c8395b27e Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026 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+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: 17 Comm: ksoftirqd/0 Not tainted syzkaller #0 0f3775a9ea948f8f8f06e34e337f4a1c8395b27e Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026 RIP: 0010:__in6_dev_get include/net/addrconf.h:342 [inline] RIP: 0010:ip6_ignore_linkdown include/net/addrconf.h:433 [inline] RIP: 0010:find_match+0xbb/0x10e0 net/ipv6/route.c:781 Code: 74 08 48 89 df e8 65 fe e5 fc 48 89 d8 bb c0 00 00 00 48 03 18 48 89 d8 48 c1 e8 03 48 b9 00 00 00 00 00 fc ff df 80 3c 08 00 <74> 08 48 89 df e8 3b fe e5 fc 48 8b 1b 48 85 db 0f 84 e5 0b 00 00 RSP: 0018:ffffc90000117058 EFLAGS: 00000246 RAX: 1ffff1102626e418 RBX: ffff8881313720c0 RCX: dffffc0000000000 RDX: ffff888103652600 RSI: 0000000000000000 RDI: 0000000000000000 RBP: ffffc90000117110 R08: ffffc900001173a0 R09: ffffc900001173b0 R10: ffffc90000117510 R11: fffff52000022ea6 R12: 0000000000000001 R13: 1ffff110216e0918 R14: 0000000000000003 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff8881f6e00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000056248c3861f0 CR3: 000000010c36e000 CR4: 00000000003526b0 Call Trace: __find_rr_leaf+0x24e/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+0x2ee/0x9e0 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:626 [inline] fib6_rule_lookup+0x4ee/0x6d0 net/ipv6/fib6_rules.c:117 ip6_route_input_lookup net/ipv6/route.c:2347 [inline] ip6_route_input+0x62e/0x8f0 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:5789 [inline] __netif_receive_skb net/core/dev.c:5902 [inline] process_backlog+0x44b/0xad0 net/core/dev.c:6238 __napi_poll+0xd3/0x610 net/core/dev.c:6889 napi_poll net/core/dev.c:6958 [inline] net_rx_action+0x5ea/0xd80 net/core/dev.c:7080 handle_softirqs+0x1aa/0x630 kernel/softirq.c:621 run_ksoftirqd+0x20/0x30 kernel/softirq.c:999 smpboot_thread_fn+0x492/0x8b0 kernel/smpboot.c:164 kthread+0x2c9/0x370 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 net_ratelimit: 116877 callbacks suppressed bridge0: received packet on ªªªªª( 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 ªªªªª( with own address as source address (addr:aa:aa:aa:aa:aa:1b, vlan:0) bridge0: received packet on ªªªªª( with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0) bridge0: received packet on ªªªªª( with own address as source address (addr:aa:aa:aa:aa:aa:1b, vlan:0) bridge0: received packet on ªªªªª( with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0) bridge0: received packet on ªªªªª( 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:06:76:ab:35:1c:2b, vlan:0) bridge0: received packet on ªªªªª( 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) net_ratelimit: 132797 callbacks suppressed bridge0: received packet on ªªªªª( 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:06:76:ab:35:1c:2b, vlan:0) bridge0: received packet on ªªªªª( 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 ªªªªª( 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:06:76:ab:35:1c:2b, vlan:0) bridge0: received packet on ªªªªª( with own address as source address (addr:aa:aa:aa:aa:aa:1b, vlan:0) bridge0: received packet on ªªªªª( with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0) bridge0: received packet on ªªªªª( with own address as source address (addr:aa:aa:aa:aa:aa:1b, vlan:0) bridge0: received packet on ªªªªª( with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0)