INFO: task syz-executor:810 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:810 tgid:810 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: 0033:0x7f84653560d7 RSP: 002b:00007ffcb83b2f70 EFLAGS: 00000202 ORIG_RAX: 000000000000002c RAX: ffffffffffffffda RBX: 000055558bd74500 RCX: 00007f84653560d7 RDX: 0000000000000028 RSI: 00007f8466144670 RDI: 0000000000000003 RBP: 0000000000000001 R08: 00007ffcb83b2fd4 R09: 000000000000000c R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000003 R13: 0000000000000000 R14: 00007f8466144670 R15: 0000000000000000 NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 37 Comm: khungtaskd Not tainted syzkaller #0 8900111b7fef672e0561e32e4ed045c7fbde3c06 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: 13 Comm: kworker/u8:1 Not tainted syzkaller #0 8900111b7fef672e0561e32e4ed045c7fbde3c06 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 Workqueue: netns cleanup_net RIP: 0010:update_stack_state+0x3da/0x4b0 arch/x86/kernel/unwind_frame.c:252 Code: 8b 05 1a 1d c0 7e 49 39 45 00 74 0e 48 8b 7d d0 e8 1b fc ff ff 49 89 c6 eb 1d 4c 8b 75 d0 4c 89 f0 48 c1 e8 03 42 80 3c 20 00 <74> 08 4c 89 f7 e8 7c 95 9a 00 4d 8b 36 48 83 c3 48 48 89 d8 48 c1 RSP: 0018:ffffc900000070b8 EFLAGS: 00000246 RAX: 1ffff92000000f2b RBX: ffffc90000007208 RCX: ffffc90000007901 RDX: ffffc90000007950 RSI: 1ffff92000000e42 RDI: ffffc90000007260 RBP: ffffc90000007178 R08: ffffc900000072d0 R09: ffffc900000072c8 R10: 0000000000000007 R11: ffffffff8175cb90 R12: dffffc0000000000 R13: ffffc90000007230 R14: ffffc90000007958 R15: 1ffff92000000e49 FS: 0000000000000000(0000) GS:ffff8881f6e00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000055649da0baf8 CR3: 0000000120acc000 CR4: 00000000003526b0 Call Trace: unwind_next_frame+0x3c1/0x750 arch/x86/kernel/unwind_frame.c:315 arch_stack_walk+0x138/0x170 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0xaa/0x100 kernel/stacktrace.c:122 kasan_save_stack mm/kasan/common.c:49 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:70 kasan_save_alloc_info+0x40/0x50 mm/kasan/generic.c:565 unpoison_slab_object mm/kasan/common.c:321 [inline] __kasan_slab_alloc+0x73/0x90 mm/kasan/common.c:347 kasan_slab_alloc include/linux/kasan.h:251 [inline] slab_post_alloc_hook mm/slub.c:4202 [inline] slab_alloc_node mm/slub.c:4251 [inline] kmem_cache_alloc_noprof+0x1bf/0x410 mm/slub.c:4260 skb_clone+0x229/0x460 net/core/skbuff.c:2082 deliver_clone net/bridge/br_forward.c:125 [inline] maybe_deliver net/bridge/br_forward.c:191 [inline] br_flood+0x4ed/0x730 net/bridge/br_forward.c:237 br_handle_frame_finish+0x12f9/0x1760 net/bridge/br_input.c:215 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+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] igmpv3_clear_delrec+0x64/0x480 net/ipv4/igmp.c:1268 ip_mc_destroy_dev+0x64/0x400 net/ipv4/igmp.c:1815 inetdev_destroy net/ipv4/devinet.c:336 [inline] inetdev_event+0x7f6/0x12a0 net/ipv4/devinet.c:1643 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 net_ratelimit: 103771 callbacks suppressed bridge0: received packet on veth0_to_bridge with own address as source address (addr:22:eb:f2:09:7f: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:22:eb:f2:09:7f: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:22:eb:f2:09:7f: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 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 bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0)