INFO: task syz.0.244:6909 blocked for more than 143 seconds. Tainted: G L syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.0.244 state:D stack:28152 pid:6909 tgid:6908 ppid:5846 task_flags:0x400040 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5256 [inline] __schedule+0x14bc/0x5000 kernel/sched/core.c:6863 __schedule_loop kernel/sched/core.c:6945 [inline] schedule+0x165/0x360 kernel/sched/core.c:6960 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7017 __mutex_lock_common kernel/locking/mutex.c:692 [inline] __mutex_lock+0x7e6/0x1350 kernel/locking/mutex.c:776 __tun_chr_ioctl+0x37a/0x1df0 drivers/net/tun.c:3078 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:597 [inline] __se_sys_ioctl+0xfc/0x170 fs/ioctl.c:583 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f013278f749 RSP: 002b:00007f01336cc038 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007f01329e5fa0 RCX: 00007f013278f749 RDX: 0000200000000040 RSI: 00000000400454ca RDI: 0000000000000003 RBP: 00007f0132813f91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f01329e6038 R14: 00007f01329e5fa0 R15: 00007f0132b0fa28 INFO: task syz.0.244:6911 blocked for more than 143 seconds. Tainted: G L syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.0.244 state:D stack:27608 pid:6911 tgid:6908 ppid:5846 task_flags:0x400140 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5256 [inline] __schedule+0x14bc/0x5000 kernel/sched/core.c:6863 __schedule_loop kernel/sched/core.c:6945 [inline] schedule+0x165/0x360 kernel/sched/core.c:6960 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7017 __mutex_lock_common kernel/locking/mutex.c:692 [inline] __mutex_lock+0x7e6/0x1350 kernel/locking/mutex.c:776 rtnl_lock net/core/rtnetlink.c:80 [inline] rtnetlink_rcv_msg+0x71c/0xb70 net/core/rtnetlink.c:6964 netlink_rcv_skb+0x208/0x470 net/netlink/af_netlink.c:2550 netlink_unicast_kernel net/netlink/af_netlink.c:1318 [inline] netlink_unicast+0x82f/0x9e0 net/netlink/af_netlink.c:1344 netlink_sendmsg+0x805/0xb30 net/netlink/af_netlink.c:1894 sock_sendmsg_nosec net/socket.c:727 [inline] __sock_sendmsg+0x21c/0x270 net/socket.c:742 ____sys_sendmsg+0x505/0x820 net/socket.c:2592 ___sys_sendmsg+0x21f/0x2a0 net/socket.c:2646 __sys_sendmsg net/socket.c:2678 [inline] __do_sys_sendmsg net/socket.c:2683 [inline] __se_sys_sendmsg net/socket.c:2681 [inline] __x64_sys_sendmsg+0x19b/0x260 net/socket.c:2681 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f013278f749 RSP: 002b:00007f01336ab038 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 00007f01329e6090 RCX: 00007f013278f749 RDX: 0000000020040084 RSI: 00002000000000c0 RDI: 0000000000000004 RBP: 00007f0132813f91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f01329e6128 R14: 00007f01329e6090 R15: 00007f0132b0fa28 Showing all locks held in the system: 1 lock held by kthreadd/2: 4 locks held by kworker/0:0/9: 4 locks held by kworker/u8:0/12: 4 locks held by kworker/u8:1/13: 1 lock held by khungtaskd/31: #0: ffffffff8df419e0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8df419e0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline] #0: ffffffff8df419e0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775 3 locks held by kworker/u8:2/36: #0: ffff88814d9db148 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3232 [inline] #0: ffff88814d9db148 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x1770 kernel/workqueue.c:3340 #1: ffffc90000ac7b80 ((work_completion)(&(&net->ipv6.addr_chk_work)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3233 [inline] #1: ffffc90000ac7b80 ((work_completion)(&(&net->ipv6.addr_chk_work)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x1770 kernel/workqueue.c:3340 #2: ffffffff8f311b48 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] #2: ffffffff8f311b48 (rtnl_mutex){+.+.}-{4:4}, at: addrconf_verify_work+0x19/0x30 net/ipv6/addrconf.c:4734 4 locks held by kworker/u8:3/50: 4 locks held by kworker/u8:4/60: 5 locks held by kworker/1:2/888: 4 locks held by kworker/u8:5/1027: #0: ffff888032aa9948 ((wq_completion)wg-kex-wg1#7){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3232 [inline] #0: ffff888032aa9948 ((wq_completion)wg-kex-wg1#7){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x1770 kernel/workqueue.c:3340 #1: ffffc9000408fb80 ((work_completion)(&peer->transmit_handshake_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3233 [inline] #1: ffffc9000408fb80 ((work_completion)(&peer->transmit_handshake_work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x1770 kernel/workqueue.c:3340 #2: ffff888077b7d308 (&wg->static_identity.lock){++++}-{4:4}, at: wg_noise_handshake_create_initiation+0x105/0x750 drivers/net/wireguard/noise.c:529 #3: ffff888058d4f030 (&handshake->lock){++++}-{4:4}, at: wg_noise_handshake_create_initiation+0x116/0x750 drivers/net/wireguard/noise.c:530 8 locks held by kworker/u8:6/1134: 3 locks held by kworker/u8:7/1146: 3 locks held by kworker/u8:8/1306: 3 locks held by kworker/u8:9/1339: 3 locks held by kworker/u8:10/2124: 3 locks held by kworker/R-krdsd/3397: 3 locks held by kworker/u8:11/3486: 3 locks held by kworker/u8:12/3500: 4 locks held by kworker/u8:13/3830: 2 locks held by kworker/u8:14/4539: 3 locks held by kworker/u8:15/4586: 1 lock held by klogd/5190: 2 locks held by udevd/5201: 2 locks held by dhcpcd/5495: 1 lock held by dhcpcd/5496: 3 locks held by crond/5573: 2 locks held by getty/5586: #0: ffff8880342250a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc9000332e2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x449/0x1460 drivers/tty/n_tty.c:2211 2 locks held by syz-executor/5817: 2 locks held by udevd/5827: 3 locks held by kworker/0:4/5833: 2 locks held by syz-executor/5847: 1 lock held by syz-executor/5848: 4 locks held by syz-executor/5849: 4 locks held by kworker/1:3/5886: #0: ffff88807d561148 ((wq_completion)wg-kex-wg2#6){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3232 [inline] #0: ffff88807d561148 ((wq_completion)wg-kex-wg2#6){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x1770 kernel/workqueue.c:3340 #1: ffffc900043afb80 ((work_completion)(&({ do { const void *__vpp_verify = (typeof((worker) + 0))((void *)0); (void)__vpp_verify; } while (0); ({ unsigned long __ptr; __ptr = (unsigned long) ((__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 kernel/workqueue.c:3233 [inline] #1: ffffc900043afb80 ((work_completion)(&({ do { const void *__vpp_verify = (typeof((worker) + 0))((void *)0); (void)__vpp_verify; } while (0); ({ unsigned long __ptr; __ptr = (unsigned long) ((__typeof_unqual__(*((worker))) *)(( unsigned long)((worker)))); (typeof((__typeof_unqual__(*((worker))) *)(( unsigned long)((worker))))) (__ptr + (((__per_cpu_offset[(cpu)])))); }); })->work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x1770 kernel/workqueue.c:3340 #2: ffff888077b79308 (&wg->static_identity.lock){++++}-{4:4}, at: wg_noise_handshake_consume_response+0x1c7/0xab0 drivers/net/wireguard/noise.c:742 #3: ffff888058d4d278 (&handshake->lock){++++}-{4:4}, at: wg_noise_handshake_consume_response+0x262/0xab0 drivers/net/wireguard/noise.c:753 2 locks held by kworker/1:5/5894: 3 locks held by kworker/1:6/5901: 3 locks held by kworker/0:5/5914: #0: ffff88813ff16948 ((wq_completion)events_power_efficient){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3232 [inline] #0: ffff88813ff16948 ((wq_completion)events_power_efficient){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x1770 kernel/workqueue.c:3340 #1: ffffc9000458fb80 ((reg_check_chans).work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3233 [inline] #1: ffffc9000458fb80 ((reg_check_chans).work){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x1770 kernel/workqueue.c:3340 #2: ffffffff8f311b48 (rtnl_mutex){+.+.}-{4:4}, at: reg_check_chans_work+0xa1/0xf00 net/wireless/reg.c:2453 3 locks held by kworker/u8:16/5947: 4 locks held by kworker/0:9/5953: 3 locks held by kworker/u8:17/5965: 2 locks held by kworker/u8:18/5975: #0: ffff88802069d148 ((wq_completion)iou_exit){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3232 [inline] #0: ffff88802069d148 ((wq_completion)iou_exit){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x1770 kernel/workqueue.c:3340 #1: ffffc9000461fb80 ((work_completion)(&ctx->exit_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3233 [inline] #1: ffffc9000461fb80 ((work_completion)(&ctx->exit_work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x1770 kernel/workqueue.c:3340 2 locks held by kworker/u8:19/6276: 5 locks held by kworker/1:8/6405: 4 locks held by syz.2.242/6896: 2 locks held by syz.2.242/6897: 1 lock held by syz.1.243/6898: #0: ffffffff8e77b6a8 (tty_mutex){+.+.}-{4:4}, at: tty_release_struct+0xae/0xd0 drivers/tty/tty_io.c:1691 1 lock held by syz.0.244/6909: #0: ffffffff8f311b48 (rtnl_mutex){+.+.}-{4:4}, at: __tun_chr_ioctl+0x37a/0x1df0 drivers/net/tun.c:3078 1 lock held by syz.0.244/6911: #0: ffffffff8f311b48 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline] #0: ffffffff8f311b48 (rtnl_mutex){+.+.}-{4:4}, at: rtnetlink_rcv_msg+0x71c/0xb70 net/core/rtnetlink.c:6964 2 locks held by kworker/0:10/6914: 4 locks held by kworker/0:11/6916: #0: ffff88807cec4548 ((wq_completion)wg-kex-wg2#2){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3232 [inline] #0: ffff88807cec4548 ((wq_completion)wg-kex-wg2#2){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x1770 kernel/workqueue.c:3340 #1: ffffc90005577b80 ((work_completion)(&({ do { const void *__vpp_verify = (typeof((worker) + 0))((void *)0); (void)__vpp_verify; } while (0); ({ unsigned long __ptr; __ptr = (unsigned long) ((__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 kernel/workqueue.c:3233 [inline] #1: ffffc90005577b80 ((work_completion)(&({ do { const void *__vpp_verify = (typeof((worker) + 0))((void *)0); (void)__vpp_verify; } while (0); ({ unsigned long __ptr; __ptr = (unsigned long) ((__typeof_unqual__(*((worker))) *)(( unsigned long)((worker)))); (typeof((__typeof_unqual__(*((worker))) *)(( unsigned long)((worker))))) (__ptr + (((__per_cpu_offset[(cpu)])))); }); })->work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x1770 kernel/workqueue.c:3340 #2: ffff8880779b5308 (&wg->static_identity.lock){++++}-{4:4}, at: wg_noise_handshake_consume_initiation+0x150/0x900 drivers/net/wireguard/noise.c:598 #3: ffff888058ce2ad8 (&handshake->lock){++++}-{4:4}, at: wg_noise_handshake_consume_initiation+0x4bf/0x900 drivers/net/wireguard/noise.c:632 4 locks held by kworker/1:11/6921: 3 locks held by kworker/1:12/6924: ============================================= NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 31 Comm: khungtaskd Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 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] __sys_info lib/sys_info.c:157 [inline] sys_info+0x135/0x170 lib/sys_info.c:165 check_hung_uninterruptible_tasks kernel/hung_task.c:346 [inline] watchdog+0xf95/0xfe0 kernel/hung_task.c:515 kthread+0x711/0x8a0 kernel/kthread.c:463 ret_from_fork+0x599/0xb30 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 101 PID: 5495 Comm: dhcpcd Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 RIP: 0010:stackdepot_memcmp lib/stackdepot.c:576 [inline] RIP: 0010:find_stack lib/stackdepot.c:610 [inline] RIP: 0010:stack_depot_save_flags+0x1c1/0x850 lib/stackdepot.c:668 Code: 24 04 85 db 75 5d 4d 8b 3f 4d 39 e7 74 52 41 39 6f 10 75 f2 45 39 57 14 75 ec 31 c0 49 8b 0c c6 49 3b 4c c7 20 75 df 48 ff c0 <41> 39 c5 75 ed 83 fe 02 72 2f 49 8d 7f 1c 41 8b 5f 1c 85 db 74 11 RSP: 0018:ffffc90003516fd8 EFLAGS: 00000206 RAX: 0000000000000003 RBX: ffff88802d5de100 RCX: ffffffff821d84e2 RDX: 000000006aa1d46b RSI: 0000000000000001 RDI: 000000008979cdac RBP: 00000000a6ec21e8 R08: 00000000931913d8 R09: 00000000303f2c3e R10: 0000000000000010 R11: ffffffff81ada000 R12: ffff88823ba21e80 R13: 0000000000000010 R14: ffffc90003517080 R15: ffff888049b99fd0 FS: 00007f205d253740(0000) GS:ffff888125f35000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00002000003b5030 CR3: 0000000031296000 CR4: 00000000003526f0 Call Trace: save_stack+0x103/0x1f0 mm/page_owner.c:166 __reset_page_owner+0x71/0x1f0 mm/page_owner.c:320 reset_page_owner include/linux/page_owner.h:25 [inline] free_pages_prepare mm/page_alloc.c:1395 [inline] __free_frozen_pages+0xbc8/0xd30 mm/page_alloc.c:2943 discard_slab mm/slub.c:3346 [inline] __put_partials+0x146/0x170 mm/slub.c:3886 put_cpu_partial+0x1f2/0x2d0 mm/slub.c:3961 __slab_free+0x288/0x2a0 mm/slub.c:5952 qlink_free mm/kasan/quarantine.c:163 [inline] qlist_free_all+0x97/0x100 mm/kasan/quarantine.c:179 kasan_quarantine_reduce+0x148/0x160 mm/kasan/quarantine.c:286 __kasan_slab_alloc+0x22/0x80 mm/kasan/common.c:349 kasan_slab_alloc include/linux/kasan.h:252 [inline] slab_post_alloc_hook mm/slub.c:4953 [inline] slab_alloc_node mm/slub.c:5263 [inline] __do_kmalloc_node mm/slub.c:5656 [inline] __kmalloc_node_track_caller_noprof+0x526/0x820 mm/slub.c:5764 kmalloc_reserve+0x136/0x290 net/core/skbuff.c:608 __alloc_skb+0x27e/0x430 net/core/skbuff.c:690 alloc_skb include/linux/skbuff.h:1383 [inline] alloc_skb_with_frags+0xca/0x890 net/core/skbuff.c:6712 sock_alloc_send_pskb+0x84d/0x980 net/core/sock.c:2995 unix_dgram_sendmsg+0x454/0x1840 net/unix/af_unix.c:2130 sock_sendmsg_nosec net/socket.c:727 [inline] __sock_sendmsg+0x21c/0x270 net/socket.c:742 sock_write_iter+0x279/0x360 net/socket.c:1195 do_iter_readv_writev+0x623/0x8c0 fs/read_write.c:-1 vfs_writev+0x31a/0x960 fs/read_write.c:1057 do_writev+0x14d/0x2d0 fs/read_write.c:1103 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f205d2dd407 Code: 48 89 fa 4c 89 df e8 38 aa 00 00 8b 93 08 03 00 00 59 5e 48 83 f8 fc 74 1a 5b c3 0f 1f 84 00 00 00 00 00 48 8b 44 24 10 0f 05 <5b> c3 0f 1f 80 00 00 00 00 83 e2 39 83 fa 08 75 de e8 23 ff ff ff RSP: 002b:00007ffc64a386b0 EFLAGS: 00000202 ORIG_RAX: 0000000000000014 RAX: ffffffffffffffda RBX: 00007f205d253740 RCX: 00007f205d2dd407 RDX: 0000000000000005 RSI: 00007ffc64a38710 RDI: 000000000000000a RBP: 000055b407894870 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000202 R12: 000055b4329b91f0 R13: 000000000000012c R14: 0000000000004801 R15: 000055b4329b88a4