INFO: task syz.4.4533:22514 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.4.4533 state:D stack:28120 pid:22514 tgid:22513 ppid:16857 task_flags:0x400040 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5387 [inline] __schedule+0x17b4/0x5680 kernel/sched/core.c:7188 __schedule_loop kernel/sched/core.c:7267 [inline] schedule+0x164/0x360 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+0x7f5/0x1550 kernel/locking/mutex.c:806 device_lock include/linux/device.h:1040 [inline] usbdev_open+0x182/0x770 drivers/usb/core/devio.c:1054 chrdev_open+0x4cd/0x5e0 fs/char_dev.c:411 do_dentry_open+0x785/0x14e0 fs/open.c:947 vfs_open+0x3b/0x340 fs/open.c:1079 do_open fs/namei.c:4699 [inline] path_openat+0x2e08/0x3860 fs/namei.c:4858 do_file_open+0x23e/0x4a0 fs/namei.c:4887 do_sys_openat2+0x113/0x200 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+0x138/0x170 fs/open.c:1381 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x15f/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f5e4535d04e RSP: 002b:00007f5e46178b28 EFLAGS: 00000246 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 00007f5e461796c0 RCX: 00007f5e4535d04e RDX: 0000000000000002 RSI: 00007f5e46178c00 RDI: ffffffffffffff9c RBP: 00007f5e46178c00 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: cccccccccccccccd R13: 00007f5e45616038 R14: 00007f5e45615fa0 R15: 00007f5e4573fa48 Showing all locks held in the system: 1 lock held by kthreadd/2: 3 locks held by kworker/0:0/9: 2 locks held by kworker/0:1/10: 3 locks held by kworker/1:0/24: 1 lock held by khungtaskd/30: #0: ffffffff8e95cce0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline] #0: ffffffff8e95cce0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline] #0: ffffffff8e95cce0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775 2 locks held by kworker/1:2/807: 2 locks held by kworker/0:2/1676: 2 locks held by kworker/R-bat_e/3425: 1 lock held by klogd/5197: 2 locks held by dhcpcd/5502: 2 locks held by dhcpcd/5503: 2 locks held by getty/5596: #0: ffff8880373170a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc9000322b2e8 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x45c/0x13a0 drivers/tty/n_tty.c:2211 1 lock held by syz-executor/5824: 2 locks held by kworker/1:5/5903: 4 locks held by kworker/1:6/5918: #0: ffff888058cd4940 ((wq_completion)wg-kex-wg2#24){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3277 [inline] #0: ffff888058cd4940 ((wq_completion)wg-kex-wg2#24){+.+.}-{0:0}, at: process_scheduled_works+0xa35/0x1860 kernel/workqueue.c:3385 #1: ffffc90004ec7c40 ((work_completion)(&({ do { const void *__vpp_verify = (typeof((worker) + 0))((void *)0); (void)__vpp_verify; } while (0); ((typeof((__typeof_unqual__(*((worker))) *)(( unsigned long)((worker)))))((unsigned long)((__typeof_unqual__(*((worker))) *)(( unsigned long)((worker)))) + (((__per_cpu_offset[(cpu)]))))); })->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3278 [inline] #1: ffffc90004ec7c40 ((work_completion)(&({ do { const void *__vpp_verify = (typeof((worker) + 0))((void *)0); (void)__vpp_verify; } while (0); ((typeof((__typeof_unqual__(*((worker))) *)(( unsigned long)((worker)))))((unsigned long)((__typeof_unqual__(*((worker))) *)(( unsigned long)((worker)))) + (((__per_cpu_offset[(cpu)]))))); })->work)){+.+.}-{0:0}, at: process_scheduled_works+0xa70/0x1860 kernel/workqueue.c:3385 #2: ffff888077c25380 (&wg->static_identity.lock){++++}-{4:4}, at: wg_noise_handshake_consume_initiation+0x1a1/0x9a0 drivers/net/wireguard/noise.c:598 #3: ffff8880325034b8 (&handshake->lock){++++}-{4:4}, at: wg_noise_handshake_consume_initiation+0x58b/0x9a0 drivers/net/wireguard/noise.c:632 3 locks held by kworker/0:6/5960: #0: ffff88813fe55d40 ((wq_completion)events_power_efficient){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3277 [inline] #0: ffff88813fe55d40 ((wq_completion)events_power_efficient){+.+.}-{0:0}, at: process_scheduled_works+0xa35/0x1860 kernel/workqueue.c:3385 #1: ffffc90004fe7c40 ((reg_check_chans).work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3278 [inline] #1: ffffc90004fe7c40 ((reg_check_chans).work){+.+.}-{0:0}, at: process_scheduled_works+0xa70/0x1860 kernel/workqueue.c:3385 #2: ffffffff8fde1640 (rtnl_mutex){+.+.}-{4:4}, at: reg_check_chans_work+0xab/0x1090 net/wireless/reg.c:2466 7 locks held by kworker/u8:13/6209: 4 locks held by kworker/u8:2/12599: 6 locks held by kworker/u8:10/12610: 3 locks held by kworker/u8:11/12612: 2 locks held by syz-executor/14469: 5 locks held by kworker/1:3/15738: 5 locks held by syz-executor/16293: 4 locks held by kworker/u8:1/18880: 5 locks held by kworker/u8:6/18881: 2 locks held by kworker/u8:12/18882: 4 locks held by kworker/u8:14/18883: 4 locks held by kworker/u8:15/18884: 3 locks held by kworker/u8:16/18885: 3 locks held by kworker/u8:18/18888: 3 locks held by kworker/u8:20/18890: #0: ffff888031ac8140 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3277 [inline] #0: ffff888031ac8140 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_scheduled_works+0xa35/0x1860 kernel/workqueue.c:3385 #1: ffffc90003a17c40 ((work_completion)(&(&net->ipv6.addr_chk_work)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3278 [inline] #1: ffffc90003a17c40 ((work_completion)(&(&net->ipv6.addr_chk_work)->work)){+.+.}-{0:0}, at: process_scheduled_works+0xa70/0x1860 kernel/workqueue.c:3385 #2: ffffffff8fde1640 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] #2: ffffffff8fde1640 (rtnl_mutex){+.+.}-{4:4}, at: addrconf_verify_work+0x19/0x30 net/ipv6/addrconf.c:4746 4 locks held by kworker/u8:24/18895: 4 locks held by kworker/u8:25/18896: 7 locks held by kworker/u9:5/20198: #0: ffff888025a4f140 ((wq_completion)hci1){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3277 [inline] #0: ffff888025a4f140 ((wq_completion)hci1){+.+.}-{0:0}, at: process_scheduled_works+0xa35/0x1860 kernel/workqueue.c:3385 #1: ffffc900046f7c40 ((work_completion)(&hdev->cmd_sync_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3278 [inline] #1: ffffc900046f7c40 ((work_completion)(&hdev->cmd_sync_work)){+.+.}-{0:0}, at: process_scheduled_works+0xa70/0x1860 kernel/workqueue.c:3385 #2: ffff8880a3d90ea0 (&hdev->req_lock){+.+.}-{4:4}, at: hci_cmd_sync_work+0x1d3/0x400 net/bluetooth/hci_sync.c:331 #3: ffff8880a3d900b8 (&hdev->lock){+.+.}-{4:4}, at: hci_abort_conn_sync+0xa6f/0x1190 net/bluetooth/hci_sync.c:5744 #4: ffffffff8ff6f120 (hci_cb_list_lock){+.+.}-{4:4}, at: hci_connect_cfm include/net/bluetooth/hci_core.h:2136 [inline] #4: ffffffff8ff6f120 (hci_cb_list_lock){+.+.}-{4:4}, at: hci_conn_failed+0x165/0x340 net/bluetooth/hci_conn.c:1342 #5: ffff888029c032f8 (&conn->lock#2){+.+.}-{4:4}, at: l2cap_conn_del+0x92/0x570 net/bluetooth/l2cap_core.c:1777 #6: ffffffff8e962fe8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:311 [inline] #6: ffffffff8e962fe8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x2d0/0x770 kernel/rcu/tree_exp.h:961 1 lock held by syz.4.4533/22514: #0: ffff88802ab161d8 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1040 [inline] #0: ffff88802ab161d8 (&dev->mutex){....}-{4:4}, at: usbdev_open+0x182/0x770 drivers/usb/core/devio.c:1054 3 locks held by kworker/1:1/22792: 2 locks held by syz.7.4693/23116: 6 locks held by syz.6.4704/23153: 2 locks held by syz.8.4707/23165: 4 locks held by syz.5.4708/23171: 2 locks held by syz.7.4710/23180: 1 lock held by syz.8.4711/23182: ============================================= NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 30 Comm: khungtaskd Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026 Call Trace: dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120 nmi_cpu_backtrace+0x274/0x2d0 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x17a/0x300 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+0x135/0x170 lib/sys_info.c:165 check_hung_uninterruptible_tasks kernel/hung_task.c:353 [inline] watchdog+0xfd3/0x1030 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 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 6209 Comm: kworker/u8:13 Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026 Workqueue: events_unbound nsim_dev_trap_report_work RIP: 0010:__lock_acquire+0x6e8/0x2cf0 kernel/locking/lockdep.c:5211 Code: 00 83 3d ba bd a9 18 00 75 13 48 63 44 24 18 48 0f a3 05 cb 2d a6 12 0f 83 8a 1e 00 00 49 8b 9e 80 0b 00 00 48 83 7c 24 28 00 <75> 19 83 3d 8f bd a9 18 00 0f 95 c0 48 83 fb ff 0f 94 c1 08 c1 0f RSP: 0018:ffffc90000006850 EFLAGS: 00000002 RAX: 0000000000000007 RBX: 39529a686290c103 RCX: ffffffff93e8f8e8 RDX: 0000000000000008 RSI: ffff888032b668e8 RDI: ffff888032b65c40 RBP: 0000000000000000 R08: ffffffff81770256 R09: ffffffff8e95cce0 R10: ffffc90000006b58 R11: ffffffff81b0f560 R12: 0000000000000003 R13: ffff888032b668e8 R14: ffff888032b65c40 R15: 0000000000000007 FS: 0000000000000000(0000) GS:ffff88812521e000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000555576285a28 CR3: 000000003624c000 CR4: 00000000003526f0 Call Trace: lock_acquire+0x106/0x350 kernel/locking/lockdep.c:5868 rcu_lock_acquire include/linux/rcupdate.h:300 [inline] rcu_read_lock include/linux/rcupdate.h:838 [inline] class_rcu_constructor include/linux/rcupdate.h:1181 [inline] unwind_next_frame+0xc3/0x2550 arch/x86/kernel/unwind_orc.c:495 arch_stack_walk+0x11b/0x150 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0xa9/0x100 kernel/stacktrace.c:122 kasan_save_stack mm/kasan/common.c:57 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:78 kasan_save_free_info+0x46/0x50 mm/kasan/generic.c:584 poison_slab_object mm/kasan/common.c:253 [inline] __kasan_slab_free+0x5c/0x80 mm/kasan/common.c:285 kasan_slab_free include/linux/kasan.h:235 [inline] slab_free_hook mm/slub.c:2689 [inline] slab_free mm/slub.c:6246 [inline] kmem_cache_free+0x182/0x650 mm/slub.c:6373 kfree_skb_reason include/linux/skbuff.h:1322 [inline] kfree_skb include/linux/skbuff.h:1331 [inline] ip6_mc_input+0x8de/0xbd0 net/ipv6/ip6_input.c:633 ip_sabotage_in+0x1e1/0x270 net/bridge/br_netfilter_hooks.c:984 nf_hook_entry_hookfn include/linux/netfilter.h:158 [inline] nf_hook_slow+0xc5/0x220 net/netfilter/core.c:619 nf_hook include/linux/netfilter.h:273 [inline] NF_HOOK+0x21f/0x3c0 include/linux/netfilter.h:316 __netif_receive_skb_one_core net/core/dev.c:6209 [inline] __netif_receive_skb net/core/dev.c:6322 [inline] netif_receive_skb_internal net/core/dev.c:6408 [inline] netif_receive_skb+0x278/0xbf0 net/core/dev.c:6467 NF_HOOK+0xa4/0x3a0 include/linux/netfilter.h:318 br_handle_frame_finish+0x1541/0x1c80 net/bridge/br_input.c:-1 br_nf_hook_thresh+0x3dd/0x4c0 net/bridge/br_netfilter_hooks.c:-1 br_nf_pre_routing_finish_ipv6+0x91f/0xc30 net/bridge/br_netfilter_ipv6.c:-1 NF_HOOK include/linux/netfilter.h:318 [inline] br_nf_pre_routing_ipv6+0x374/0x6f0 net/bridge/br_netfilter_ipv6.c:183 nf_hook_entry_hookfn include/linux/netfilter.h:158 [inline] nf_hook_bridge_pre net/bridge/br_input.c:291 [inline] br_handle_frame+0x1277/0x1510 net/bridge/br_input.c:442 __netif_receive_skb_core+0x98f/0x3170 net/core/dev.c:6096 __netif_receive_skb_one_core net/core/dev.c:6207 [inline] __netif_receive_skb net/core/dev.c:6322 [inline] process_backlog+0x76d/0x1950 net/core/dev.c:6673 __napi_poll+0xae/0x340 net/core/dev.c:7737 napi_poll net/core/dev.c:7800 [inline] net_rx_action+0x627/0xf70 net/core/dev.c:7957 handle_softirqs+0x22a/0x840 kernel/softirq.c:622 do_softirq+0x76/0xd0 kernel/softirq.c:523 __local_bh_enable_ip+0xf8/0x130 kernel/softirq.c:450 spin_unlock_bh include/linux/spinlock.h:396 [inline] nsim_dev_trap_report drivers/net/netdevsim/dev.c:891 [inline] nsim_dev_trap_report_work+0x7c7/0xb80 drivers/net/netdevsim/dev.c:922 process_one_work kernel/workqueue.c:3302 [inline] process_scheduled_works+0xb5d/0x1860 kernel/workqueue.c:3385 worker_thread+0xa53/0xfc0 kernel/workqueue.c:3466 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