INFO: task syz-executor:982 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:982 tgid:982 ppid:1 flags:0x00004004 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_preempt_disabled+0x14/0x30 kernel/sched/core.c:8033 __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+0x259/0x4f0 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+0x8c3/0xa60 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+0x68a/0x700 net/socket.c:2216 __do_sys_sendto net/socket.c:2228 [inline] __se_sys_sendto net/socket.c:2224 [inline] __x64_sys_sendto+0xe9/0x100 net/socket.c:2224 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: 0033:0x7f1f31557f57 RSP: 002b:00007fffb4b8a150 EFLAGS: 00000202 ORIG_RAX: 000000000000002c RAX: ffffffffffffffda RBX: 00005555821aa500 RCX: 00007f1f31557f57 RDX: 0000000000000028 RSI: 00007f1f32344670 RDI: 0000000000000003 RBP: 0000000000000001 R08: 00007fffb4b8a1b4 R09: 000000000000000c R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000003 R13: 0000000000000000 R14: 00007f1f32344670 R15: 0000000000000000 NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 37 Comm: khungtaskd Not tainted syzkaller #0 4609c3d09534f6cc029e796bf5efdb893db8a517 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: 33 Comm: rcuop/1 Not tainted syzkaller #0 4609c3d09534f6cc029e796bf5efdb893db8a517 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026 RIP: 0010:skb_flow_limit net/core/dev.c:4938 [inline] RIP: 0010:enqueue_to_backlog+0x278/0xbe0 net/core/dev.c:4994 Code: 00 00 fc ff df 0f b6 04 08 84 c0 0f 85 46 06 00 00 44 8b 3d be 27 c1 02 41 d1 ff 44 8b 6d 9c 44 89 ef 44 89 fe e8 38 0d 08 fd <45> 39 fd 48 89 5d 80 73 14 e8 6a 0b 08 fd 49 bf 00 00 00 00 00 fc RSP: 0018:ffffc90000006f80 EFLAGS: 00000046 RAX: ffffffff847fb128 RBX: ffff8881f6e51044 RCX: 0000000000000100 RDX: ffff88810367cc00 RSI: 00000000000001f4 RDI: 000000000000000b RBP: ffffc90000007030 R08: 0000000000000003 R09: 0000000000000004 R10: dffffc0000000000 R11: fffff52000000ddc R12: 1ffff11022aaaaf2 R13: 000000000000000b R14: ffff888115555780 R15: 00000000000001f4 FS: 0000000000000000(0000) GS:ffff8881f6e00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000055b40b67faf8 CR3: 000000010c780000 CR4: 00000000003526b0 Call Trace: netif_rx_internal+0xab/0x340 net/core/dev.c:5313 __netif_rx+0x24/0x230 net/core/dev.c:5333 veth_forward_skb drivers/net/veth.c:324 [inline] veth_xmit+0x42e/0xb20 drivers/net/veth.c:378 __netdev_start_xmit include/linux/netdevice.h:5008 [inline] netdev_start_xmit include/linux/netdevice.h:5017 [inline] xmit_one net/core/dev.c:3681 [inline] dev_hard_start_xmit+0x21b/0x760 net/core/dev.c:3697 __dev_queue_xmit+0x1927/0x3680 net/core/dev.c:4537 dev_queue_xmit include/linux/netdevice.h:3141 [inline] br_dev_queue_push_xmit+0x55c/0x700 net/bridge/br_forward.c:53 NF_HOOK include/linux/netfilter.h:317 [inline] br_forward_finish net/bridge/br_forward.c:66 [inline] NF_HOOK include/linux/netfilter.h:317 [inline] __br_forward+0x25c/0x390 net/bridge/br_forward.c:115 deliver_clone net/bridge/br_forward.c:131 [inline] br_flood+0x67e/0x730 net/bridge/br_forward.c:246 br_handle_frame_finish+0x11eb/0x17a0 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+0xfb1/0x3ab0 net/core/dev.c:5683 __netif_receive_skb_one_core net/core/dev.c:5787 [inline] __netif_receive_skb net/core/dev.c:5902 [inline] process_backlog+0x3e5/0xad0 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 __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+0x5d9/0xd40 kernel/rcu/tree.c:2594 nocb_cb_wait kernel/rcu/tree_nocb.h:923 [inline] rcu_nocb_cb_kthread+0x524/0xb30 kernel/rcu/tree_nocb.h:957 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: 121371 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:ca:4f:60:52:2b:77, 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 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:ca:4f:60:52:2b:77, vlan:0) bridge0: received packet on bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:1b, vlan:0)