INFO: task syz-executor:5531 blocked for more than 122 seconds. Not tainted 6.12.23-syzkaller-gd9fd901baa98 #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor state:D stack:0 pid:5531 tgid:5531 ppid:1 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:5924 [inline] __schedule+0x145b/0x1f10 kernel/sched/core.c:7750 __schedule_loop kernel/sched/core.c:7831 [inline] schedule+0xc6/0x240 kernel/sched/core.c:7846 schedule_preempt_disabled+0x14/0x30 kernel/sched/core.c:7903 __mutex_lock_common kernel/locking/mutex.c:692 [inline] __mutex_lock+0x836/0x1b60 kernel/locking/mutex.c:786 __mutex_lock_slowpath+0xe/0x20 kernel/locking/mutex.c:1117 mutex_lock+0x102/0x1c0 kernel/locking/mutex.c:270 rtnl_lock net/core/rtnetlink.c:79 [inline] rtnetlink_rcv_msg+0x75f/0xa00 net/core/rtnetlink.c:6675 netlink_rcv_skb+0x22b/0x4a0 net/netlink/af_netlink.c:2537 rtnetlink_rcv+0x20/0x30 net/core/rtnetlink.c:6696 netlink_unicast_kernel net/netlink/af_netlink.c:1316 [inline] netlink_unicast+0x8c6/0xa60 net/netlink/af_netlink.c:1342 netlink_sendmsg+0x7f0/0xaf0 net/netlink/af_netlink.c:1886 sock_sendmsg_nosec net/socket.c:730 [inline] __sock_sendmsg net/socket.c:745 [inline] __sys_sendto+0x66a/0x6f0 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:52 [inline] do_syscall_64+0x58/0xf0 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x76/0x7e RIP: 0033:0x7fb787590763 RSP: 002b:00007fff5771aa28 EFLAGS: 00000202 ORIG_RAX: 000000000000002c RAX: ffffffffffffffda RBX: 00007fb7882e4620 RCX: 00007fb787590763 RDX: 000000000000002c RSI: 00007fb7882e4670 RDI: 0000000000000003 RBP: 0000000000000001 R08: 00007fff5771aa44 R09: 000000000000000c R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000003 R13: 0000000000000000 R14: 00007fb7882e4670 R15: 0000000000000000 NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 37 Comm: khungtaskd Not tainted 6.12.23-syzkaller-gd9fd901baa98 #0 f1acc3ef52b3e732a05c4f7a2560722db90bb473 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 Call Trace: __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:229 [inline] watchdog+0xd8f/0xed0 kernel/hung_task.c:385 kthread+0x2c7/0x370 kernel/kthread.c:389 ret_from_fork+0x64/0xa0 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: 2514 Comm: kworker/u8:11 Not tainted 6.12.23-syzkaller-gd9fd901baa98 #0 f1acc3ef52b3e732a05c4f7a2560722db90bb473 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 Workqueue: netns cleanup_net RIP: 0010:ip6_rcv_core+0x127/0x1300 net/ipv6/ip6_input.c:166 Code: 00 00 4c 89 f0 48 c1 e8 03 49 bf 00 00 00 00 00 fc ff df 42 80 3c 38 00 74 08 4c 89 f7 e8 e1 f2 00 fd 4d 8b 36 65 49 ff 46 08 <4c> 8d 63 70 4c 89 e0 48 c1 e8 03 42 0f b6 04 38 84 c0 0f 85 ac 0d RSP: 0018:ffffc90000007488 EFLAGS: 00000202 RAX: 1ffff110278a2688 RBX: ffff88811c038780 RCX: ffff88811e333900 RDX: 0000000000000100 RSI: 0000000000000002 RDI: 0000000000000003 RBP: ffffc90000007530 R08: ffff88811e333900 R09: 0000000000000002 R10: 000000000000a888 R11: 0000000000000100 R12: ffff88811b21c118 R13: ffff88812c2c3540 R14: 0000607e08e38d90 R15: dffffc0000000000 FS: 0000000000000000(0000) GS:ffff8881f6e00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f4c8c5b5f40 CR3: 0000000109bc0000 CR4: 00000000003526b0 DR0: fffffffffffffff8 DR1: 0000000000000006 DR2: 0200000000000000 DR3: 0000000000000005 DR6: 00000000ffff0ff0 DR7: 0000000000000400 Call Trace: ipv6_rcv+0xce/0x220 net/ipv6/ip6_input.c:306 __netif_receive_skb_one_core net/core/dev.c:5757 [inline] __netif_receive_skb net/core/dev.c:5870 [inline] netif_receive_skb_internal net/core/dev.c:5956 [inline] netif_receive_skb+0x147/0x7b0 net/core/dev.c:6015 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+0xf48/0x3940 net/core/dev.c:5651 __netif_receive_skb_one_core net/core/dev.c:5755 [inline] __netif_receive_skb net/core/dev.c:5870 [inline] process_backlog+0x3e5/0xae0 net/core/dev.c:6202 __napi_poll+0xd0/0x610 net/core/dev.c:6853 napi_poll net/core/dev.c:6922 [inline] net_rx_action+0x584/0xce0 net/core/dev.c:7044 handle_softirqs+0x1ab/0x630 kernel/softirq.c:603 __do_softirq+0xf/0x16 kernel/softirq.c:641 do_softirq+0xa6/0x100 kernel/softirq.c:485 __local_bh_enable_ip+0x74/0x80 kernel/softirq.c:412 __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+0x608/0x1940 net/ipv6/addrconf.c:3953 addrconf_notify+0x17a/0xea0 net/ipv6/addrconf.c:-1 notifier_call_chain+0x10b/0x2c0 kernel/notifier.c:93 raw_notifier_call_chain+0x31/0x40 kernel/notifier.c:461 call_netdevice_notifiers_info net/core/dev.c:2067 [inline] call_netdevice_notifiers_extack net/core/dev.c:2105 [inline] call_netdevice_notifiers net/core/dev.c:2119 [inline] unregister_netdevice_many_notify+0xe32/0x1bd0 net/core/dev.c:11485 unregister_netdevice_many net/core/dev.c:11547 [inline] default_device_exit_batch+0x810/0x8a0 net/core/dev.c:12030 ops_exit_list net/core/net_namespace.c:178 [inline] cleanup_net+0x72e/0xc70 net/core/net_namespace.c:642 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+0x2c7/0x370 kernel/kthread.c:389 ret_from_fork+0x64/0xa0 arch/x86/kernel/process.c:153 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 net_ratelimit: 82198 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 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:c6:5c:76:5e:37:a8, 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:c6:5c:76:5e:37:a8, vlan:0) bridge0: received packet on veth0_to_bridge with own address as source address (addr:c6:5c:76:5e:37:a8, 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) net_ratelimit: 90471 callbacks suppressed 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:c6:5c:76:5e:37:a8, vlan:0) bridge0: received packet on veth0_to_bridge with own address as source address (addr:c6:5c:76:5e:37:a8, 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: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:c6:5c:76:5e:37:a8, vlan:0) bridge0: received packet on veth0_to_bridge with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0)