INFO: task syz-executor:7901 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:7901 tgid:7901 ppid:1 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:5996 [inline] __schedule+0x134f/0x1ea0 kernel/sched/core.c:7843 __schedule_loop kernel/sched/core.c:7924 [inline] schedule+0xc5/0x240 kernel/sched/core.c:7939 schedule_preempt_disabled+0x14/0x30 kernel/sched/core.c:7996 __mutex_lock_common kernel/locking/mutex.c:707 [inline] __mutex_lock+0x960/0x1bb0 kernel/locking/mutex.c:803 __mutex_lock_slowpath+0xe/0x20 kernel/locking/mutex.c:1134 mutex_lock+0x113/0x1d0 kernel/locking/mutex.c:285 rtnl_lock net/core/rtnetlink.c:79 [inline] rtnetlink_rcv_msg+0x79e/0xa40 net/core/rtnetlink.c:6672 netlink_rcv_skb+0x256/0x4f0 net/netlink/af_netlink.c:2545 rtnetlink_rcv+0x20/0x30 net/core/rtnetlink.c:6693 netlink_unicast_kernel net/netlink/af_netlink.c:1313 [inline] netlink_unicast+0x8c0/0xa60 net/netlink/af_netlink.c:1339 netlink_sendmsg+0x7fe/0xb10 net/netlink/af_netlink.c:1889 sock_sendmsg_nosec net/socket.c:730 [inline] __sock_sendmsg net/socket.c:745 [inline] __sys_sendto+0x718/0x790 net/socket.c:2217 __do_sys_sendto net/socket.c:2229 [inline] __se_sys_sendto net/socket.c:2225 [inline] __x64_sys_sendto+0xe9/0x100 net/socket.c:2225 x64_sys_call+0x2c2c/0x2ee0 arch/x86/include/generated/asm/syscalls_64.h:45 do_syscall_x64 arch/x86/entry/common.c:47 [inline] do_syscall_64+0x57/0xf0 arch/x86/entry/common.c:78 entry_SYSCALL_64_after_hwframe+0x76/0x7e RIP: 0033:0x7f3906f560d7 RSP: 002b:00007ffda6af2ca0 EFLAGS: 00000202 ORIG_RAX: 000000000000002c RAX: ffffffffffffffda RBX: 000055556c9bf500 RCX: 00007f3906f560d7 RDX: 0000000000000028 RSI: 00007f3907d44670 RDI: 0000000000000003 RBP: 0000000000000001 R08: 00007ffda6af2d04 R09: 000000000000000c R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000003 R13: 0000000000000000 R14: 00007f3907d44670 R15: 0000000000000000 NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 37 Comm: khungtaskd Not tainted syzkaller #0 001c7e68fa735976e9f6b7ad125989e1d2b10b0e Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 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: 376 Comm: kworker/u8:4 Not tainted syzkaller #0 001c7e68fa735976e9f6b7ad125989e1d2b10b0e Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 Workqueue: netns cleanup_net RIP: 0010:skb_mac_header_was_set include/linux/skbuff.h:-1 [inline] RIP: 0010:skb_mac_header include/linux/skbuff.h:3056 [inline] RIP: 0010:eth_hdr include/linux/if_ether.h:24 [inline] RIP: 0010:br_handle_frame+0x5f/0xba0 net/bridge/br_input.c:329 Code: 00 74 08 4c 89 ef e8 60 0f cf fc 4d 8b 7d 00 4d 8d b7 ba 00 00 00 4d 89 f4 49 c1 ec 03 41 0f b6 04 1c 84 c0 0f 85 6a 08 00 00 <4c> 89 75 c8 45 0f b7 36 bf ff ff 00 00 44 89 f6 e8 0c 4c 77 fc 41 RSP: 0018:ffffc900000078e0 EFLAGS: 00000246 RAX: 0000000000000000 RBX: dffffc0000000000 RCX: ffff888113548000 RDX: 0000000000000100 RSI: 0000000000000000 RDI: ffffc90000007b60 RBP: ffffc90000007950 R08: ffff888113548000 R09: 0000000000000002 R10: 0000000000000000 R11: ffffffff85105430 R12: 1ffff110286f6c67 R13: ffffc90000007b60 R14: ffff8881437b633a R15: ffff8881437b6280 FS: 0000000000000000(0000) GS:ffff8881f6e00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f03d1bf84c0 CR3: 000000010c336000 CR4: 00000000003526b0 Call Trace: __netif_receive_skb_core+0xfae/0x3ab0 net/core/dev.c:5657 __netif_receive_skb_one_core net/core/dev.c:5761 [inline] __netif_receive_skb net/core/dev.c:5876 [inline] process_backlog+0x3e5/0xad0 net/core/dev.c:6212 __napi_poll+0xd3/0x610 net/core/dev.c:6863 napi_poll net/core/dev.c:6932 [inline] net_rx_action+0x5ea/0xd80 net/core/dev.c:7054 handle_softirqs+0x1aa/0x630 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+0x614/0x1980 net/ipv6/addrconf.c:3950 addrconf_notify+0x17a/0xea0 net/ipv6/addrconf.c:-1 notifier_call_chain+0x10e/0x2b0 kernel/notifier.c:93 raw_notifier_call_chain+0x31/0x40 kernel/notifier.c:461 call_netdevice_notifiers_info net/core/dev.c:2061 [inline] call_netdevice_notifiers_extack net/core/dev.c:2099 [inline] call_netdevice_notifiers net/core/dev.c:2113 [inline] unregister_netdevice_many_notify+0xe3f/0x1c30 net/core/dev.c:11495 unregister_netdevice_many net/core/dev.c:11557 [inline] default_device_exit_batch+0x828/0x8c0 net/core/dev.c:12040 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:3238 [inline] process_scheduled_works+0x7d4/0x1020 kernel/workqueue.c:3319 worker_thread+0xc70/0x10b0 kernel/workqueue.c:3400 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 ip6_tunnel: syztnl1 xmit: Local address not yet configured! net_ratelimit: 237883 callbacks suppressed +$<ś: received packet on bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:1b, vlan:0) +$<ś: received packet on bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:1b, vlan:0) +$<ś: received packet on veth0_to_bridge with own address as source address (addr:fa:d2:6c:a0:5f:a3, vlan:0) +$<ś: received packet on veth0_to_bridge with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0) +$<ś: received packet on veth0_to_bridge with own address as source address (addr:fa:d2:6c:a0:5f:a3, vlan:0) +$<ś: received packet on bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:1b, vlan:0) +$<ś: received packet on veth0_to_bridge with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0) +$<ś: received packet on veth0_to_bridge with own address as source address (addr:fa:d2:6c:a0:5f:a3, vlan:0) +$<ś: received packet on bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0) +$<ś: received packet on veth0_to_bridge with own address as source address (addr:fa:d2:6c:a0:5f:a3, vlan:0)