INFO: task syz.5.2504:13490 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.5.2504 state:D stack:25896 pid:13490 tgid:13486 ppid:9161 task_flags:0x400740 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5325 [inline] __schedule+0x1798/0x4cc0 kernel/sched/core.c:6929 __schedule_loop kernel/sched/core.c:7011 [inline] schedule+0x165/0x360 kernel/sched/core.c:7026 schedule_timeout+0x9a/0x270 kernel/time/sleep_timeout.c:75 do_wait_for_common kernel/sched/completion.c:100 [inline] __wait_for_common+0x3da/0x710 kernel/sched/completion.c:121 wait_for_common kernel/sched/completion.c:132 [inline] wait_for_completion_state+0x1c/0x40 kernel/sched/completion.c:269 coredump_wait fs/coredump.c:534 [inline] vfs_coredump+0x8cf/0x2a60 fs/coredump.c:1131 get_signal+0x1108/0x1340 kernel/signal.c:3019 arch_do_signal_or_restart+0xa0/0x790 arch/x86/kernel/signal.c:337 exit_to_user_mode_loop+0x72/0x130 kernel/entry/common.c:40 exit_to_user_mode_prepare include/linux/irq-entry-common.h:225 [inline] syscall_exit_to_user_mode_work include/linux/entry-common.h:175 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:210 [inline] do_syscall_64+0x2bd/0xfa0 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f6f3d58eec9 RSP: 002b:00007f6f3e3ac0e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca RAX: 00000000000000ca RBX: 00007f6f3d7e6098 RCX: 00007f6f3d58eec9 RDX: 00000000000f4240 RSI: 0000000000000081 RDI: 00007f6f3d7e609c RBP: 00007f6f3d7e6090 R08: 7fffffffffffffff R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f6f3d7e6128 R14: 00007ffe5bec5660 R15: 00007ffe5bec5748 Showing all locks held in the system: 1 lock held by khungtaskd/31: #0: ffffffff8e53d2e0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8e53d2e0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline] #0: ffffffff8e53d2e0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775 2 locks held by getty/5626: #0: ffff88814df950a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc900036bb2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x43e/0x1400 drivers/tty/n_tty.c:2222 4 locks held by kworker/0:6/5979: 1 lock held by syz-executor/13866: #0: ffff8880b873a018 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x2a/0x140 kernel/sched/core.c:638 1 lock held by syz.3.3212/15461: #0: ffffffff8e542c40 (rcu_state.barrier_mutex){+.+.}-{4:4}, at: rcu_barrier+0x4c/0x570 kernel/rcu/tree.c:3820 1 lock held by syz.2.3222/15488: #0: ffff8880b863a018 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x2a/0x140 kernel/sched/core.c:638 ============================================= NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 31 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025 Call Trace: dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120 nmi_cpu_backtrace+0x39e/0x3d0 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x17a/0x300 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:160 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:332 [inline] watchdog+0xf60/0xfa0 kernel/hung_task.c:495 kthread+0x711/0x8a0 kernel/kthread.c:463 ret_from_fork+0x4bc/0x870 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 3474 Comm: kworker/u8:7 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025 Workqueue: wg-kex-wg1 wg_packet_handshake_send_worker RIP: 0010:format_decode+0xea/0xe30 lib/vsprintf.c:2681 Code: db 31 ff 89 de e8 16 1b 3b f6 84 db 0f 95 c0 41 84 c6 75 16 e8 07 18 3b f6 4c 8b 74 24 18 49 81 e6 00 ff ff ff e9 57 05 00 00 <4d> 89 ee 49 c1 ee 03 48 ba 00 00 00 00 00 fc ff df 41 0f b6 04 16 RSP: 0018:ffffc9000c4c6470 EFLAGS: 00000202 RAX: ffffffff8b857a01 RBX: 0000000000000025 RCX: 0000000000000000 RDX: ffff888031128000 RSI: 0000000000000025 RDI: 0000000000000000 RBP: ffffffff8bab91a6 R08: ffff888031128000 R09: 0000000000000002 R10: 0000000000000025 R11: 0000000000000000 R12: ffffffff8bab91a6 R13: ffffc9000c4c6518 R14: 0000000000000001 R15: ffffffff8bab91a6 FS: 0000000000000000(0000) GS:ffff8881257a8000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000110c4474ac CR3: 000000000e338000 CR4: 00000000003526f0 Call Trace: vsnprintf+0x102/0xf00 lib/vsprintf.c:2869 sprintf+0xd9/0x120 lib/vsprintf.c:3089 print_time kernel/printk/printk.c:1354 [inline] info_print_prefix+0x155/0x310 kernel/printk/printk.c:1380 record_print_text+0x154/0x420 kernel/printk/printk.c:1429 printk_get_next_message+0x26d/0x7b0 kernel/printk/printk.c:2997 console_emit_next_record kernel/printk/printk.c:3065 [inline] console_flush_all+0x4ca/0xb10 kernel/printk/printk.c:3199 __console_flush_and_unlock kernel/printk/printk.c:3258 [inline] console_unlock+0xbb/0x190 kernel/printk/printk.c:3298 vprintk_emit+0x4c5/0x590 kernel/printk/printk.c:2423 _printk+0xcf/0x120 kernel/printk/printk.c:2448 ip_vs_schedule+0x1520/0x1c80 net/netfilter/ipvs/ip_vs_core.c:518 udp_conn_schedule+0x332/0x710 net/netfilter/ipvs/ip_vs_proto_udp.c:78 ip_vs_try_to_schedule net/netfilter/ipvs/ip_vs_core.c:1479 [inline] ip_vs_in_hook+0xbde/0x1b50 net/netfilter/ipvs/ip_vs_core.c:2051 nf_hook_entry_hookfn include/linux/netfilter.h:158 [inline] nf_hook_slow+0xc5/0x220 net/netfilter/core.c:623 nf_hook+0x217/0x380 include/linux/netfilter.h:273 __ip_local_out+0x4db/0x600 net/ipv4/ip_output.c:120 ip_local_out+0x26/0x70 net/ipv4/ip_output.c:129 iptunnel_xmit+0x5f8/0xa90 net/ipv4/ip_tunnel_core.c:84 udp_tunnel_xmit_skb+0x26e/0x3c0 net/ipv4/udp_tunnel_core.c:193 send4+0xa50/0xed0 drivers/net/wireguard/socket.c:85 wg_socket_send_skb_to_peer+0xd1/0x1d0 drivers/net/wireguard/socket.c:175 wg_packet_send_handshake_initiation drivers/net/wireguard/send.c:40 [inline] wg_packet_handshake_send_worker+0x1db/0x320 drivers/net/wireguard/send.c:51 process_one_work kernel/workqueue.c:3263 [inline] process_scheduled_works+0xae1/0x17b0 kernel/workqueue.c:3346 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3427 kthread+0x711/0x8a0 kernel/kthread.c:463 ret_from_fork+0x4bc/0x870 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245