INFO: task syz.4.1766:9953 blocked for more than 122 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.4.1766 state:D stack:0 pid:9953 tgid:9953 ppid:689 flags:0x00004006 Call Trace: context_switch kernel/sched/core.c:5996 [inline] __schedule+0x134a/0x1dd0 kernel/sched/core.c:7842 __schedule_loop kernel/sched/core.c:7923 [inline] schedule+0xc5/0x240 kernel/sched/core.c:7938 schedule_timeout+0xc7/0x3b0 kernel/time/timer.c:2596 do_wait_for_common kernel/sched/completion.c:95 [inline] __wait_for_common kernel/sched/completion.c:116 [inline] wait_for_common+0x369/0x650 kernel/sched/completion.c:127 wait_for_completion+0x1c/0x40 kernel/sched/completion.c:148 rcu_barrier+0x415/0x540 kernel/rcu/tree.c:4657 netdev_run_todo+0x118/0xce0 net/core/dev.c:10874 rtnl_unlock+0x12/0x20 net/core/rtnetlink.c:152 tun_detach drivers/net/tun.c:704 [inline] tun_chr_close+0xc5/0x150 drivers/net/tun.c:3520 __fput+0x1fe/0xa00 fs/file_table.c:429 ____fput+0x20/0x30 fs/file_table.c:457 task_work_run+0x1e8/0x260 kernel/task_work.c:246 exit_task_work include/linux/task_work.h:43 [inline] do_exit+0x9e3/0x2650 kernel/exit.c:953 do_group_exit+0x229/0x2f0 kernel/exit.c:1095 get_signal+0x1398/0x14e0 kernel/signal.c:2933 arch_do_signal_or_restart+0xbc/0x760 arch/x86/kernel/signal.c:337 exit_to_user_mode_loop kernel/entry/common.c:111 [inline] exit_to_user_mode_prepare include/linux/entry-common.h:328 [inline] __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline] syscall_exit_to_user_mode+0x57/0xb0 kernel/entry/common.c:218 do_syscall_64+0x63/0xf0 arch/x86/entry/common.c:84 entry_SYSCALL_64_after_hwframe+0x76/0x7e RIP: 00fb:0x294e66b3c7c44cb4 RSP: 002b:0000000000000000 EFLAGS: 00000202 ORIG_RAX: ce3d5c200518e753 RAX: 6d02b596a6d6b2c6 RBX: 46b00e13ac8c17fa RCX: 1d6d567492f1521e RDX: eb30e365dd53f3a0 RSI: c553273f825e1cf7 RDI: b331ef28487276fd RBP: 9c8c87e20081ee76 R08: cf9d780a350b4549 R09: c7e58b697db8ef3d R10: d68d02d45a22dc24 R11: 19b4d49ef33da9ed R12: 39cb75b6fa6cb3d1 R13: a8d7b5dbf29d588f R14: 9b8908dcbb4f02b4 R15: 107b9d1451766018 NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 37 Comm: khungtaskd Not tainted syzkaller #0 946995d19d674f9300a5002509ea8fae89fb6511 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+0x2c6/0x370 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: 15492 Comm: kworker/0:6 Not tainted syzkaller #0 946995d19d674f9300a5002509ea8fae89fb6511 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 Workqueue: wg-crypt-wg0 wg_packet_tx_worker RIP: 0010:update_stack_state+0x3da/0x4b0 arch/x86/kernel/unwind_frame.c:252 Code: 8b 05 1a 2d 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 6c 90 9a 00 4d 8b 36 48 83 c3 48 48 89 d8 48 c1 RSP: 0018:ffffc90000006ed8 EFLAGS: 00000246 RAX: 1ffff920007fffe4 RBX: ffffc90000007028 RCX: ffffc90003ffff01 RDX: ffffc90003ffff18 RSI: 1ffff92000000e06 RDI: ffffc90000007080 RBP: ffffc90000006f98 R08: ffffc900000070f0 R09: ffffc900000070e8 R10: 0000000000000019 R11: ffffffff8175b680 R12: dffffc0000000000 R13: ffffc90000007050 R14: ffffc90003ffff20 R15: 1ffff92000000e0d FS: 0000000000000000(0000) GS:ffff8881f6e00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fc291745000 CR3: 000000010dbbc000 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_free_info+0x4a/0x60 mm/kasan/generic.c:579 poison_slab_object mm/kasan/common.c:249 [inline] __kasan_slab_free+0x5f/0x80 mm/kasan/common.c:266 kasan_slab_free include/linux/kasan.h:234 [inline] slab_free_hook mm/slub.c:2445 [inline] slab_free mm/slub.c:4714 [inline] kmem_cache_free+0x1bd/0x4f0 mm/slub.c:4821 kfree_skbmem net/core/skbuff.c:-1 [inline] __kfree_skb+0x18f/0x210 net/core/skbuff.c:1203 sk_skb_reason_drop+0xd8/0x310 net/core/skbuff.c:1240 kfree_skb_reason include/linux/skbuff.h:1271 [inline] ip_rcv_finish_core+0xc13/0x1440 net/ipv4/ip_input.c:424 ip_rcv_finish net/ipv4/ip_input.c:447 [inline] NF_HOOK include/linux/netfilter.h:317 [inline] ip_rcv+0xe8/0x310 net/ipv4/ip_input.c:569 __netif_receive_skb_one_core net/core/dev.c:5763 [inline] __netif_receive_skb net/core/dev.c:5876 [inline] netif_receive_skb_internal net/core/dev.c:5962 [inline] netif_receive_skb+0x1f7/0x7b0 net/core/dev.c:6021 br_netif_receive_skb net/bridge/br_input.c:30 [inline] NF_HOOK include/linux/netfilter.h:317 [inline] br_pass_frame_up+0x126/0x1b0 net/bridge/br_input.c:70 br_handle_frame_finish+0x1317/0x1760 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+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+0xd0/0x610 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+0x1ad/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_read_unlock_bh include/linux/rwlock_api_smp.h:257 [inline] _raw_read_unlock_bh+0x2d/0x40 kernel/locking/spinlock.c:284 wg_socket_send_skb_to_peer+0x176/0x1e0 drivers/net/wireguard/socket.c:184 wg_packet_create_data_done drivers/net/wireguard/send.c:251 [inline] wg_packet_tx_worker+0x1d2/0x4e0 drivers/net/wireguard/send.c:276 process_one_work kernel/workqueue.c:3238 [inline] process_scheduled_works+0x7d1/0x1020 kernel/workqueue.c:3319 worker_thread+0xc70/0x10b0 kernel/workqueue.c:3400 kthread+0x2c6/0x370 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: 259849 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: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: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: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)