INFO: task syz.4.736:8271 blocked for more than 145 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.4.736       state:D stack:27784 pid:8271  tgid:8270  ppid:5823   task_flags:0x400040 flags:0x00080002
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5387 [inline]
 __schedule+0x10e9/0x6820 kernel/sched/core.c:7188
 __schedule_loop kernel/sched/core.c:7267 [inline]
 schedule+0xdd/0x390 kernel/sched/core.c:7282
 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7339
 __mutex_lock_common kernel/locking/mutex.c:712 [inline]
 __mutex_lock+0xced/0x1b10 kernel/locking/mutex.c:806
 class_mutex_constructor include/linux/mutex.h:253 [inline]
 ptmx_open drivers/tty/pty.c:800 [inline]
 ptmx_open+0x11a/0x370 drivers/tty/pty.c:767
 chrdev_open+0x234/0x6a0 fs/char_dev.c:411
 do_dentry_open+0x6d8/0x1660 fs/open.c:947
 vfs_open+0x82/0x3f0 fs/open.c:1079
 do_open fs/namei.c:4699 [inline]
 path_openat+0x208c/0x31a0 fs/namei.c:4858
 do_file_open+0x20e/0x430 fs/namei.c:4887
 do_sys_openat2+0x10d/0x1e0 fs/open.c:1364
 do_sys_open fs/open.c:1370 [inline]
 __do_sys_openat fs/open.c:1386 [inline]
 __se_sys_openat fs/open.c:1381 [inline]
 __x64_sys_openat+0x12d/0x210 fs/open.c:1381
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x10b/0xf80 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f0a5c19c819
RSP: 002b:00007f0a5cfc5028 EFLAGS: 00000246 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 00007f0a5c415fa0 RCX: 00007f0a5c19c819
RDX: 0000000000000202 RSI: 0000200000000000 RDI: ffffffffffffff9c
RBP: 00007f0a5c232c91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f0a5c416038 R14: 00007f0a5c415fa0 R15: 00007fff613cc518
 </TASK>

Showing all locks held in the system:
4 locks held by kworker/u8:0/12:
 #0: ffff88807e131140 ((wq_completion)wg-kex-wg0#5){+.+.}-{0:0}, at: process_one_work+0x12d6/0x1980 kernel/workqueue.c:3277
 #1: ffffc90000117d08 ((work_completion)(&peer->transmit_handshake_work)){+.+.}-{0:0}, at: process_one_work+0x973/0x1980 kernel/workqueue.c:3278
 #2: ffff88807d81d380 (&wg->static_identity.lock){++++}-{4:4}, at: wg_noise_handshake_create_initiation+0xec/0x610 drivers/net/wireguard/noise.c:529
 #3: ffff88802899dc58 (&handshake->lock){++++}-{4:4}, at: wg_noise_handshake_create_initiation+0x100/0x610 drivers/net/wireguard/noise.c:530
6 locks held by kworker/u8:1/13:
4 locks held by kworker/1:0/24:
 #0: ffff888034c5a940 ((wq_completion)wg-kex-wg1#2){+.+.}-{0:0}, at: process_one_work+0x12d6/0x1980 kernel/workqueue.c:3277
 #1: ffffc900001e7d08 ((work_completion)(&({ do { const void __seg_gs *__vpp_verify = (typeof((worker) + 0))((void *)0); (void)__vpp_verify; } while (0); ({ unsigned long __ptr; __asm__ ("" : "=r"(__ptr) : "0"((__typeof_unqual__(*((worker))) *)(( unsigned long)((worker))))); (typeof((__typeof_unqual__(*((worker))) *)(( unsigned long)((worker))))) (__ptr + (((__per_cpu_offset[(cpu)])))); }); })->work)){+.+.}-{0:0}, at: process_one_work+0x973/0x1980 kernel/workqueue.c:3278
 #2: ffff8880206c9380 (&wg->static_identity.lock){++++}-{4:4}, at: wg_noise_handshake_consume_response+0x22b/0x950 drivers/net/wireguard/noise.c:742
 #3: ffff88807a285c58 (&handshake->lock){++++}-{4:4}, at: wg_noise_handshake_consume_response+0x655/0x950 drivers/net/wireguard/noise.c:786
1 lock held by khungtaskd/30:
 #0: ffffffff8e7e5460 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline]
 #0: ffffffff8e7e5460 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline]
 #0: ffffffff8e7e5460 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x3d/0x184 kernel/locking/lockdep.c:6775
3 locks held by kworker/u8:2/35:
3 locks held by kworker/1:1/42:
4 locks held by kworker/u8:3/48:
3 locks held by kworker/u8:4/70:
3 locks held by kswapd0/84:
3 locks held by kworker/u8:5/138:
3 locks held by kworker/u8:6/623:
2 locks held by kworker/1:2/803:
2 locks held by kworker/0:3/1224:
3 locks held by kworker/u8:7/1319:
2 locks held by kworker/R-bat_e/3421:
6 locks held by kworker/u8:8/3518:
3 locks held by kworker/u8:9/3582:
1 lock held by jbd2/sda1-8/5157:
2 locks held by klogd/5185:
2 locks held by udevd/5196:
1 lock held by dhcpcd/5490:
1 lock held by dhcpcd/5491:
2 locks held by getty/5583:
 #0: ffff88803980f0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x24/0x80 drivers/tty/tty_ldisc.c:243
 #1: ffffc9000322b2e8 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x419/0x14f0 drivers/tty/n_tty.c:2211
4 locks held by syz-executor/5809:
1 lock held by syz-executor/5821:
2 locks held by syz-executor/5822:
2 locks held by syz-executor/5825:
4 locks held by kworker/1:3/5827:
 #0: ffff888060c08940 ((wq_completion)wg-kex-wg2#4){+.+.}-{0:0}, at: process_one_work+0x12d6/0x1980 kernel/workqueue.c:3277
 #1: ffffc90004167d08 ((work_completion)(&({ do { const void __seg_gs *__vpp_verify = (typeof((worker) + 0))((void *)0); (void)__vpp_verify; } while (0); ({ unsigned long __ptr; __asm__ ("" : "=r"(__ptr) : "0"((__typeof_unqual__(*((worker))) *)(( unsigned long)((worker))))); (typeof((__typeof_unqual__(*((worker))) *)(( unsigned long)((worker))))) (__ptr + (((__per_cpu_offset[(cpu)])))); }); })->work)){+.+.}-{0:0}, at: process_one_work+0x973/0x1980 kernel/workqueue.c:3278
 #2: ffff88803613d380 (&wg->static_identity.lock){++++}-{4:4}, at: wg_noise_handshake_consume_response+0x22b/0x950 drivers/net/wireguard/noise.c:742
 #3: ffff88802899bea0 (&handshake->lock){++++}-{4:4}, at: wg_noise_handshake_consume_response+0x2f8/0x950 drivers/net/wireguard/noise.c:753
4 locks held by kworker/1:7/5931:
2 locks held by kworker/0:5/5934:
3 locks held by kworker/0:6/5951:
3 locks held by kworker/0:7/5976:
3 locks held by kworker/u8:10/6178:
4 locks held by syz.2.733/8261:
1 lock held by syz.4.736/8271:
 #0: ffffffff8f4ffa80 (tty_mutex){+.+.}-{4:4}, at: class_mutex_constructor include/linux/mutex.h:253 [inline]
 #0: ffffffff8f4ffa80 (tty_mutex){+.+.}-{4:4}, at: ptmx_open drivers/tty/pty.c:800 [inline]
 #0: ffffffff8f4ffa80 (tty_mutex){+.+.}-{4:4}, at: ptmx_open+0x11a/0x370 drivers/tty/pty.c:767
3 locks held by udevd/8274:
4 locks held by kworker/u8:11/8275:
1 lock held by kworker/u8:12/8276:

=============================================

NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 30 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:94 [inline]
 dump_stack_lvl+0x100/0x190 lib/dump_stack.c:120
 nmi_cpu_backtrace.cold+0x12d/0x151 lib/nmi_backtrace.c:113
 nmi_trigger_cpumask_backtrace+0x1d7/0x230 lib/nmi_backtrace.c:62
 trigger_all_cpu_backtrace include/linux/nmi.h:162 [inline]
 __sys_info lib/sys_info.c:157 [inline]
 sys_info+0x141/0x190 lib/sys_info.c:165
 check_hung_uninterruptible_tasks kernel/hung_task.c:353 [inline]
 watchdog+0xcb1/0x1030 kernel/hung_task.c:561
 kthread+0x370/0x450 kernel/kthread.c:436
 ret_from_fork+0x72b/0xd50 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 5904 Comm: kworker/1:6 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026
Workqueue: events_long defense_work_handler
RIP: 0010:stack_trace_consume_entry+0x1e/0x170 kernel/stacktrace.c:83
Code: 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 48 b8 00 00 00 00 00 fc ff df 55 53 48 89 fb 48 83 c7 10 48 89 fa 48 c1 ea 03 <48> 83 ec 08 0f b6 04 02 84 c0 74 08 3c 03 0f 8e e7 00 00 00 48 8d
RSP: 0018:ffffc90000a07f80 EFLAGS: 00000a02
RAX: dffffc0000000000 RBX: ffffc90000a08058 RCX: ffffc90000a07eec
RDX: 1ffff9200014100d RSI: ffffffff81765b9a RDI: ffffc90000a08068
RBP: ffffc90000a08028 R08: 0000000000000001 R09: 0000000000000007
R10: 0000000000000200 R11: 000000000000ae38 R12: ffffffff81f3c390
R13: ffffc90000a08058 R14: 0000000000000000 R15: ffff88802ae9a500
FS:  0000000000000000(0000) GS:ffff8881243de000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f1457a00218 CR3: 0000000066eaa000 CR4: 00000000003526f0
Call Trace:
 <IRQ>
 arch_stack_walk+0x88/0xf0 arch/x86/kernel/stacktrace.c:27
 stack_trace_save+0x8e/0xc0 kernel/stacktrace.c:122
 kasan_save_stack+0x30/0x50 mm/kasan/common.c:57
 kasan_save_track+0x14/0x30 mm/kasan/common.c:78
 unpoison_slab_object mm/kasan/common.c:340 [inline]
 __kasan_slab_alloc+0x89/0x90 mm/kasan/common.c:366
 kasan_slab_alloc include/linux/kasan.h:253 [inline]
 slab_post_alloc_hook mm/slub.c:4569 [inline]
 slab_alloc_node mm/slub.c:4898 [inline]
 kmem_cache_alloc_noprof+0x241/0x6e0 mm/slub.c:4905
 skb_clone+0x190/0x400 net/core/skbuff.c:2107
 deliver_clone net/bridge/br_forward.c:125 [inline]
 br_flood+0x35c/0x650 net/bridge/br_forward.c:250
 br_handle_frame_finish+0xff4/0x1f60 net/bridge/br_input.c:229
 br_nf_hook_thresh+0x30d/0x420 net/bridge/br_netfilter_hooks.c:1161
 br_nf_pre_routing_finish_ipv6+0x659/0xdd0 net/bridge/br_netfilter_ipv6.c:153
 NF_HOOK include/linux/netfilter.h:318 [inline]
 br_nf_pre_routing_ipv6+0x39c/0x8b0 net/bridge/br_netfilter_ipv6.c:183
 br_nf_pre_routing+0x90f/0x1560 net/bridge/br_netfilter_hooks.c:509
 nf_hook_entry_hookfn include/linux/netfilter.h:158 [inline]
 nf_hook_bridge_pre net/bridge/br_input.c:291 [inline]
 br_handle_frame+0xcdd/0x1520 net/bridge/br_input.c:442
 __netif_receive_skb_core.constprop.0+0x6c5/0x3530 net/core/dev.c:6096
 __netif_receive_skb_one_core+0xb0/0x1e0 net/core/dev.c:6207
 __netif_receive_skb+0x1f/0x120 net/core/dev.c:6322
 process_backlog+0x37a/0x1580 net/core/dev.c:6673
 __napi_poll.constprop.0+0xaf/0x450 net/core/dev.c:7737
 napi_poll net/core/dev.c:7800 [inline]
 net_rx_action+0xa40/0xf20 net/core/dev.c:7957
 handle_softirqs+0x1ea/0xa00 kernel/softirq.c:622
 do_softirq kernel/softirq.c:523 [inline]
 do_softirq+0xac/0xe0 kernel/softirq.c:510
 </IRQ>
 <TASK>
 __local_bh_enable_ip+0xf8/0x120 kernel/softirq.c:450
 local_bh_enable include/linux/bottom_half.h:33 [inline]
 update_defense_level+0x607/0xf50 net/netfilter/ipvs/ip_vs_ctl.c:210
 defense_work_handler+0x26/0xd0 net/netfilter/ipvs/ip_vs_ctl.c:235
 process_one_work+0xa0e/0x1980 kernel/workqueue.c:3302
 process_scheduled_works kernel/workqueue.c:3385 [inline]
 worker_thread+0x5ef/0xe50 kernel/workqueue.c:3466
 kthread+0x370/0x450 kernel/kthread.c:436
 ret_from_fork+0x72b/0xd50 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>