INFO: task kworker/u8:15:466 blocked for more than 122 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kworker/u8:15 state:D stack:0 pid:466 tgid:466 ppid:2 flags:0x00004000 Workqueue: netns cleanup_net Call Trace: context_switch kernel/sched/core.c:6052 [inline] __schedule+0x1496/0x20b0 kernel/sched/core.c:7865 __schedule_loop kernel/sched/core.c:7942 [inline] schedule+0xc5/0x240 kernel/sched/core.c:7957 schedule_preempt_disabled+0x14/0x30 kernel/sched/core.c:8014 __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 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 NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 37 Comm: khungtaskd Not tainted syzkaller #0 8ee30d9df144bc892052d3af75bf7ae355cbcd4b Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026 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: net_ratelimit: 108968 callbacks suppressed bridge0: received packet on veth0_to_bridge with own address as source address (addr:4a:37:d0:b0:ba:c8, 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: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: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 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: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) NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 33 Comm: rcuop/1 Not tainted syzkaller #0 8ee30d9df144bc892052d3af75bf7ae355cbcd4b Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026 RIP: 0010:net_hash_mix include/net/netns/hash.h:9 [inline] RIP: 0010:xfrm_pol_bin_key+0x8e/0x160 net/xfrm/xfrm_policy.c:1497 Code: 42 80 3c 20 00 74 0e 4c 89 f7 49 89 d7 e8 9a 46 f4 fc 4c 89 fa 41 bf 08 02 00 00 4d 03 3e 4c 89 f8 48 c1 e8 03 42 0f b6 04 20 <84> c0 0f 85 a1 00 00 00 89 d8 81 c3 fb be ad de 8d 8c 02 fb be ad RSP: 0018:ffffc90000006fe8 EFLAGS: 00000a02 RAX: 0000000000000000 RBX: 0000000022431026 RCX: ffff888103679300 RDX: 000000000000000a RSI: 0000000000000000 RDI: ffffc900000072b8 RBP: ffffc90000007010 R08: 0010000000000000 R09: 0000000000000004 R10: 0000000000000000 R11: ffffffff84ebdc20 R12: dffffc0000000000 R13: 0000000000000000 R14: ffffc900000072b0 R15: ffff88811feeec88 FS: 0000000000000000(0000) GS:ffff8881f6e00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fcd983de4c0 CR3: 000000010abde000 CR4: 00000000003526b0 Call Trace: rht_key_get_hash include/linux/rhashtable.h:133 [inline] rht_key_hashfn include/linux/rhashtable.h:159 [inline] __rhashtable_lookup include/linux/rhashtable.h:604 [inline] rhashtable_lookup+0x156/0x4f0 include/linux/rhashtable.h:646 xfrm_policy_inexact_lookup_rcu net/xfrm/xfrm_policy.c:2074 [inline] xfrm_policy_lookup_bytype+0x9f3/0x14d0 net/xfrm/xfrm_policy.c:2199 xfrm_policy_lookup net/xfrm/xfrm_policy.c:2236 [inline] __xfrm_policy_check+0xb5c/0x3570 net/xfrm/xfrm_policy.c:3742 __xfrm_policy_check2+0x347/0x6f0 include/net/xfrm.h:1242 xfrm_policy_check include/net/xfrm.h:1247 [inline] xfrm6_policy_check include/net/xfrm.h:1257 [inline] icmpv6_rcv+0x115/0x1800 net/ipv6/icmp.c:917 ip6_protocol_deliver_rcu+0xbc0/0x1270 net/ipv6/ip6_input.c:436 ip6_input_finish net/ipv6/ip6_input.c:481 [inline] NF_HOOK include/linux/netfilter.h:317 [inline] ip6_input+0x1c3/0x3a0 net/ipv6/ip6_input.c:490 ip6_mc_input+0x333/0x680 net/ipv6/ip6_input.c:584 dst_input include/net/dst.h:469 [inline] ip6_rcv_finish+0x341/0x3c0 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: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: 104307 callbacks suppressed 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:4a:37:d0:b0:ba:c8, 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 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) bridge0: received packet on veth0_to_bridge with own address as source address (addr:4a:37:d0:b0:ba:c8, 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)