INFO: task syz.0.7400:1748 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.0.7400 state:D stack:27880 pid:1748 tgid:1747 ppid:626 task_flags:0x400040 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5510 [inline] __schedule+0x1709/0x5530 kernel/sched/core.c:7231 __schedule_loop kernel/sched/core.c:7308 [inline] rt_mutex_schedule+0x76/0xf0 kernel/sched/core.c:7604 rt_mutex_slowlock_block+0x55c/0x680 kernel/locking/rtmutex.c:1670 __rt_mutex_slowlock kernel/locking/rtmutex.c:1747 [inline] __rt_mutex_slowlock_locked kernel/locking/rtmutex.c:1787 [inline] rt_mutex_slowlock+0x2d4/0x780 kernel/locking/rtmutex.c:1827 __rt_mutex_lock kernel/locking/rtmutex.c:1842 [inline] __mutex_lock_common kernel/locking/rtmutex_api.c:560 [inline] mutex_lock_nested+0x168/0x1d0 kernel/locking/rtmutex_api.c:578 device_lock include/linux/device.h:1104 [inline] usbdev_open+0x151/0x790 drivers/usb/core/devio.c:1054 chrdev_open+0x4dc/0x600 fs/char_dev.c:411 do_dentry_open+0x849/0x1420 fs/open.c:947 vfs_open+0x3b/0x350 fs/open.c:1052 do_open fs/namei.c:4694 [inline] path_openat+0x2e64/0x3850 fs/namei.c:4857 do_file_open+0x23e/0x4a0 fs/namei.c:4886 do_sys_openat2+0x115/0x200 fs/open.c:1368 do_sys_open fs/open.c:1374 [inline] __do_sys_openat fs/open.c:1390 [inline] __se_sys_openat fs/open.c:1385 [inline] __x64_sys_openat+0x138/0x170 fs/open.c:1385 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline] do_syscall_64+0x17b/0x530 arch/x86/entry/syscall_64.c:85 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f4c0b49e6ce RSP: 002b:00007f4c09735b28 EFLAGS: 00000246 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 00007f4c097366c0 RCX: 00007f4c0b49e6ce RDX: 0000000000109301 RSI: 00007f4c09735c00 RDI: ffffffffffffff9c RBP: 00007f4c09735c00 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: cccccccccccccccd R13: 00007f4c0b766038 R14: 00007f4c0b765fa0 R15: 00007ffd695e8ff8 Showing all locks held in the system: locks held by kworker/1:0/32: 6, on CPU#1: #0: ffff88801e6ea938 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline] #0: ffff88801e6ea938 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:840 [inline] #0: ffff88801e6ea938 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work+0x7fd/0x1480 kernel/workqueue.c:3344 #1: ffffc90000a6fc60 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline] #1: ffffc90000a6fc60 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:840 [inline] #1: ffffc90000a6fc60 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work+0x7fd/0x1480 kernel/workqueue.c:3344 #2: ffff88802aa90210 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1104 [inline] #2: ffff88802aa90210 (&dev->mutex){....}-{4:4}, at: hub_event+0x187/0x4cf0 drivers/usb/core/hub.c:5899 #3: ffff88802aebc210 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1104 [inline] #3: ffff88802aebc210 (&dev->mutex){....}-{4:4}, at: __device_attach+0x88/0x450 drivers/base/dd.c:1073 #4: ffff88803b7421d8 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1104 [inline] #4: ffff88803b7421d8 (&dev->mutex){....}-{4:4}, at: __device_attach+0x88/0x450 drivers/base/dd.c:1073 #5: ffffffff8e260880 (umhelper_sem){++++}-{4:4}, at: usermodehelper_read_trylock+0xfc/0x2c0 kernel/umh.c:212 locks held by khungtaskd/39: 1, last CPU#0: #0: ffffffff8e3c3880 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline] #0: ffffffff8e3c3880 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:840 [inline] #0: ffffffff8e3c3880 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6835 locks held by getty/5360: 2, on CPU#1: #0: ffff888035f1b0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc900044d32e0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x460/0x1360 drivers/tty/n_tty.c:2211 locks held by udevd/24463: 4, on CPU#1: #0: ffff88802c13aa68 (&p->lock){+.+.}-{4:4}, at: seq_read_iter+0xa5/0xcb0 fs/seq_file.c:183 #1: ffff88805c623478 (&of->mutex#2){+.+.}-{4:4}, at: kernfs_seq_start+0x5d/0x420 fs/kernfs/file.c:165 #2: ffff888079df3a58 (kn->active#30){++++}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:73 [inline] #2: ffff888079df3a58 (kn->active#30){++++}-{0:0}, at: kernfs_seq_start+0xb2/0x420 fs/kernfs/file.c:166 #3: ffff88802aebc210 (&dev->mutex){....}-{4:4}, at: device_lock_interruptible include/linux/device.h:1109 [inline] #3: ffff88802aebc210 (&dev->mutex){....}-{4:4}, at: manufacturer_show+0x26/0xa0 drivers/usb/core/sysfs.c:142 locks held by kworker/1:10/26218: 10, last CPU#1: #0: ffff888079f0c138 ((wq_completion)wg-crypt-wg1#19){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline] #0: ffff888079f0c138 ((wq_completion)wg-crypt-wg1#19){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:840 [inline] #0: ffff888079f0c138 ((wq_completion)wg-crypt-wg1#19){+.+.}-{0:0}, at: process_one_work+0x7fd/0x1480 kernel/workqueue.c:3344 #1: ffffc90005b6fc60 ((work_completion)(&peer->transmit_packet_work)){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline] #1: ffffc90005b6fc60 ((work_completion)(&peer->transmit_packet_work)){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:840 [inline] #1: ffffc90005b6fc60 ((work_completion)(&peer->transmit_packet_work)){+.+.}-{0:0}, at: process_one_work+0x7fd/0x1480 kernel/workqueue.c:3344 #2: ffffffff8e259320 (local_bh){.+.+}-{1:3}, at: __local_bh_disable_ip+0x3c/0x420 kernel/softirq.c:163 #3: ffffffff8e3c3880 (rcu_read_lock){....}-{1:3}, at: __local_bh_disable_ip+0x3c/0x420 kernel/softirq.c:163 #4: ffff88803a2a6230 (&peer->endpoint_lock){++..}-{3:3}, at: read_lock_bh include/linux/rwlock_rt.h:45 [inline] #4: ffff88803a2a6230 (&peer->endpoint_lock){++..}-{3:3}, at: wg_socket_send_skb_to_peer+0x6e/0x200 drivers/net/wireguard/socket.c:172 #5: ffffffff8e3c3880 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline] #5: ffffffff8e3c3880 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:840 [inline] #5: ffffffff8e3c3880 (rcu_read_lock){....}-{1:3}, at: rt_read_lock+0x277/0x4b0 kernel/locking/spinlock_rt.c:251 #6: ffffffff8e259320 (local_bh){.+.+}-{1:3}, at: __local_bh_disable_ip+0x3c/0x420 kernel/softirq.c:163 #7: ffffffff8e3c38e0 (rcu_read_lock_bh){....}-{1:3}, at: local_bh_disable include/linux/bottom_half.h:20 [inline] #7: ffffffff8e3c38e0 (rcu_read_lock_bh){....}-{1:3}, at: rcu_read_lock_bh include/linux/rcupdate.h:893 [inline] #7: ffffffff8e3c38e0 (rcu_read_lock_bh){....}-{1:3}, at: send4+0x217/0xec0 drivers/net/wireguard/socket.c:38 #8: ffffe8ffffd90228 ((&({ do { const void *__vpp_verify = (typeof((dst_cache->cache) + 0))((void *)0); (void)__vpp_verify; } while (0); ((typeof((__typeof_unqual__(*((dst_cache->cache))) *)(( unsigned long)((dst_cache->cache)))))((unsigned long)((__typeof_unqual__(*((dst_cache->cache))) *)(( unsigned long)((dst_cache->cache)))) + (((__per_cpu_offset[(i)]))))); })->bh_lock)){+...}-{3:3}, at: spin_lock include/linux/spinlock_rt.h:45 [inline] #8: ffffe8ffffd90228 ((&({ do { const void *__vpp_verify = (typeof((dst_cache->cache) + 0))((void *)0); (void)__vpp_verify; } while (0); ((typeof((__typeof_unqual__(*((dst_cache->cache))) *)(( unsigned long)((dst_cache->cache)))))((unsigned long)((__typeof_unqual__(*((dst_cache->cache))) *)(( unsigned long)((dst_cache->cache)))) + (((__per_cpu_offset[(i)]))))); })->bh_lock)){+...}-{3:3}, at: dst_cache_get_ip4+0xb1/0x2c0 net/core/dst_cache.c:89 #9: ffffffff8e3c3880 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline] #9: ffffffff8e3c3880 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:840 [inline] #9: ffffffff8e3c3880 (rcu_read_lock){....}-{1:3}, at: __rt_spin_lock kernel/locking/spinlock_rt.c:50 [inline] #9: ffffffff8e3c3880 (rcu_read_lock){....}-{1:3}, at: rt_spin_lock+0x1e0/0x400 kernel/locking/spinlock_rt.c:57 locks held by kworker/u8:91/27444: 7, last CPU#1: #0: ffff88801aea4138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline] #0: ffff88801aea4138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:840 [inline] #0: ffff88801aea4138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work+0x7fd/0x1480 kernel/workqueue.c:3344 #1: ffffc90005857c60 ((work_completion)(&(&kfence_timer)->work)){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline] #1: ffffc90005857c60 ((work_completion)(&(&kfence_timer)->work)){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:840 [inline] #1: ffffc90005857c60 ((work_completion)(&(&kfence_timer)->work)){+.+.}-{0:0}, at: process_one_work+0x7fd/0x1480 kernel/workqueue.c:3344 #2: ffffffff8e251c70 (cpu_hotplug_lock){++++}-{0:0}, at: static_key_enable+0x12/0x20 kernel/jump_label.c:222 #3: ffffffff8e4995d8 (jump_label_mutex){+.+.}-{4:4}, at: jump_label_lock kernel/jump_label.c:27 [inline] #3: ffffffff8e4995d8 (jump_label_mutex){+.+.}-{4:4}, at: static_key_enable_cpuslocked+0xcb/0x240 kernel/jump_label.c:207 #4: ffffffff8e268598 (text_mutex){+.+.}-{4:4}, at: arch_jump_label_transform_apply+0x17/0x30 arch/x86/kernel/jump_label.c:145 #5: ffffffff8e3c3880 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline] #5: ffffffff8e3c3880 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:840 [inline] #5: ffffffff8e3c3880 (rcu_read_lock){....}-{1:3}, at: __pte_offset_map+0x29/0x200 mm/pgtable-generic.c:290 #6: ffff88801ae98c58 (ptlock_ptr(ptdesc)#2){+.+.}-{3:3}, at: spin_lock include/linux/spinlock_rt.h:45 [inline] #6: ffff88801ae98c58 (ptlock_ptr(ptdesc)#2){+.+.}-{3:3}, at: pte_offset_map_lock+0x13d/0x210 mm/pgtable-generic.c:404 locks held by syz.0.7400/1748: 1, on CPU#0: #0: ffff88802aa90210 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1104 [inline] #0: ffff88802aa90210 (&dev->mutex){....}-{4:4}, at: usbdev_open+0x151/0x790 drivers/usb/core/devio.c:1054 ============================================= NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 39 Comm: khungtaskd Tainted: G L syzkaller #0 PREEMPT_{RT,(full)} Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/16/2026 Call Trace: dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120 nmi_cpu_backtrace+0x274/0x2d0 lib/nmi_backtrace.c:122 nmi_trigger_cpumask_backtrace+0x17a/0x380 lib/nmi_backtrace.c:65 trigger_all_cpu_backtrace include/linux/nmi.h:162 [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:353 [inline] watchdog+0xfd7/0x1030 kernel/hung_task.c:561 kthread+0x388/0x470 kernel/kthread.c:436 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 26218 Comm: kworker/1:10 Tainted: G L syzkaller #0 PREEMPT_{RT,(full)} Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/16/2026 Workqueue: wg-crypt-wg1 wg_packet_tx_worker RIP: 0010:mark_lock_accessed kernel/locking/lockdep.c:1546 [inline] RIP: 0010:__bfs kernel/locking/lockdep.c:1784 [inline] RIP: 0010:__bfs_backwards kernel/locking/lockdep.c:1876 [inline] RIP: 0010:check_irq_usage kernel/locking/lockdep.c:2812 [inline] RIP: 0010:check_prev_add kernel/locking/lockdep.c:3185 [inline] RIP: 0010:check_prevs_add kernel/locking/lockdep.c:3300 [inline] RIP: 0010:validate_chain kernel/locking/lockdep.c:3924 [inline] RIP: 0010:__lock_acquire+0x18a7/0x2e40 kernel/locking/lockdep.c:5254 Code: 05 6e 80 28 14 4d 85 ff 0f 84 bf 01 00 00 49 8b 47 10 48 85 c0 0f 84 8b 0d 00 00 8b 0d 5a 80 28 14 39 48 5c 0f 84 6f ff ff ff <89> 48 5c 49 8b 47 30 48 85 c0 74 23 41 0f b6 4f 2a 89 ca 80 e2 fa RSP: 0018:ffffc90005b6f110 EFLAGS: 00000087 RAX: ffffffff936f6348 RBX: 00000000000003cd RCX: 00000000001be0a4 RDX: ffffffff965b3c68 RSI: ffff88805b8a2d10 RDI: ffff88805b8a1f40 RBP: 651ef6ff83dc329a R08: 00000000000003cd R09: 0000000000000020 R10: 0000000000000000 R11: ffffffff81a16ef0 R12: 00000000000000f6 R13: ffffffff936a2ac0 R14: ffff88805b8a2d10 R15: ffffffff9659d378 FS: 0000000000000000(0000) GS:ffff888125af2000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000555570ac3a78 CR3: 000000000e1b0000 CR4: 00000000003526f0 Call Trace: lock_acquire+0x115/0x350 kernel/locking/lockdep.c:5906 _raw_spin_lock_nested+0x32/0x50 kernel/locking/spinlock.c:382 raw_spin_rq_lock_nested+0x2d/0x160 kernel/sched/core.c:667 raw_spin_rq_lock kernel/sched/sched.h:1664 [inline] _task_rq_lock+0xc0/0x440 kernel/sched/core.c:762 class_task_rq_lock_constructor kernel/sched/sched.h:1974 [inline] migrate_disable_switch kernel/sched/core.c:2464 [inline] __schedule+0x1888/0x5530 kernel/sched/core.c:7086 preempt_schedule_irq+0x4d/0xa0 kernel/sched/core.c:7553 irqentry_exit_to_kernel_mode include/linux/irq-entry-common.h:539 [inline] irqentry_exit+0x14f/0x8f0 kernel/entry/common.c:167 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:674 RIP: 0010:save_dst_trace_buffer+0x1f1/0x5b0 net/core/dst.c:104 Code: 74 73 e8 92 22 9c f8 48 8b 1c 24 48 81 fb 40 ff 17 00 74 2d e8 80 22 9c f8 48 81 c3 c0 00 00 00 49 83 c6 18 48 83 44 24 30 e8 <48> 83 44 24 28 e8 49 83 c5 e8 49 83 c7 e8 49 83 c4 e8 e9 72 ff ff RSP: 0018:ffffc90005b6f6c0 EFLAGS: 00000287 RAX: ffffffff89298130 RBX: 0000000000171cc0 RCX: ffff88805b8a1f40 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: ffffc90005b6f848 R08: 0000000000000000 R09: 0000000000000000 R10: ffffc90005b6f620 R11: fffff52000b6dec8 R12: e00000000cac5653 R13: e00000000cac5652 R14: 1ffffffff353a9c4 R15: e00000000cac5652 dst_release+0x28/0x1b0 net/core/dst.c:250 dst_cache_per_cpu_dst_set+0x89/0x1a0 net/core/dst_cache.c:32 dst_cache_per_cpu_get+0x252/0x2d0 net/core/dst_cache.c:56 dst_cache_get_ip4+0x113/0x2c0 net/core/dst_cache.c:91 send4+0x380/0xec0 drivers/net/wireguard/socket.c:49 wg_socket_send_skb_to_peer+0xe8/0x200 drivers/net/wireguard/socket.c:174 wg_packet_create_data_done drivers/net/wireguard/send.c:251 [inline] wg_packet_tx_worker+0x1c8/0x7e0 drivers/net/wireguard/send.c:276 process_one_work+0xaaf/0x1480 kernel/workqueue.c:3379 process_scheduled_works kernel/workqueue.c:3462 [inline] worker_thread+0xb05/0x10d0 kernel/workqueue.c:3543 kthread+0x388/0x470 kernel/kthread.c:436 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245