INFO: task syz.5.5076:23602 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.5.5076 state:D stack:27096 pid:23602 tgid:23601 ppid:16891 task_flags:0x400040 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5388 [inline] __schedule+0x1821/0x5740 kernel/sched/core.c:7189 __schedule_loop kernel/sched/core.c:7268 [inline] schedule+0x164/0x360 kernel/sched/core.c:7283 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7340 __mutex_lock_common kernel/locking/mutex.c:726 [inline] __mutex_lock+0x7f7/0x1550 kernel/locking/mutex.c:820 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+0x822/0x13a0 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+0x174/0x580 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fe426f5d68e RSP: 002b:00007fe427dacb28 EFLAGS: 00000246 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 00007fe427dad6c0 RCX: 00007fe426f5d68e RDX: 0000000000000082 RSI: 00007fe427dacc00 RDI: ffffffffffffff9c RBP: 00007fe427dacc00 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: cccccccccccccccd R13: 00007fe427216038 R14: 00007fe427215fa0 R15: 00007fe42733fa48 Showing all locks held in the system: 1 lock held by khungtaskd/30: #0: ffffffff8e95cc20 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline] #0: ffffffff8e95cc20 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline] #0: ffffffff8e95cc20 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775 2 locks held by getty/5385: #0: ffff888036a570a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc900032332e8 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x45c/0x13a0 drivers/tty/n_tty.c:2211 3 locks held by kworker/1:5/5726: #0: ffff888021a85d40 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3289 [inline] #0: ffff888021a85d40 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_scheduled_works+0xa35/0x1860 kernel/workqueue.c:3397 #1: ffffc90005447c40 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3290 [inline] #1: ffffc90005447c40 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_scheduled_works+0xa70/0x1860 kernel/workqueue.c:3397 #2: ffff88802b6471d8 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1040 [inline] #2: ffff88802b6471d8 (&dev->mutex){....}-{4:4}, at: hub_event+0x17f/0x4f30 drivers/usb/core/hub.c:5899 4 locks held by udevd/5805: #0: ffff888079505638 (&p->lock){+.+.}-{4:4}, at: seq_read_iter+0xb7/0xe10 fs/seq_file.c:183 #1: ffff88807efaec80 (&of->mutex#2){+.+.}-{4:4}, at: kernfs_seq_start+0x5c/0x420 fs/kernfs/file.c:172 #2: ffff888043331788 (kn->active#31){++++}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:80 [inline] #2: ffff888043331788 (kn->active#31){++++}-{0:0}, at: kernfs_seq_start+0xb2/0x420 fs/kernfs/file.c:173 #3: ffff88809c7571d8 (&dev->mutex){....}-{4:4}, at: device_lock_interruptible include/linux/device.h:1045 [inline] #3: ffff88809c7571d8 (&dev->mutex){....}-{4:4}, at: manufacturer_show+0x26/0xa0 drivers/usb/core/sysfs.c:142 6 locks held by kworker/1:10/6356: #0: ffff888021a85d40 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3289 [inline] #0: ffff888021a85d40 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_scheduled_works+0xa35/0x1860 kernel/workqueue.c:3397 #1: ffffc9000330fc40 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3290 [inline] #1: ffffc9000330fc40 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_scheduled_works+0xa70/0x1860 kernel/workqueue.c:3397 #2: ffff88802b5ad1d8 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1040 [inline] #2: ffff88802b5ad1d8 (&dev->mutex){....}-{4:4}, at: hub_event+0x17f/0x4f30 drivers/usb/core/hub.c:5899 #3: ffff8880441711d8 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1040 [inline] #3: ffff8880441711d8 (&dev->mutex){....}-{4:4}, at: __device_attach+0x88/0x450 drivers/base/dd.c:1076 #4: ffff88803347c1a0 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1040 [inline] #4: ffff88803347c1a0 (&dev->mutex){....}-{4:4}, at: __device_attach+0x88/0x450 drivers/base/dd.c:1076 #5: ffffffff8e7f9968 (umhelper_sem){++++}-{4:4}, at: usermodehelper_read_trylock+0xfc/0x2c0 kernel/umh.c:214 5 locks held by kworker/0:9/6364: #0: ffff888021a85d40 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3289 [inline] #0: ffff888021a85d40 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_scheduled_works+0xa35/0x1860 kernel/workqueue.c:3397 #1: ffffc9000358fc40 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3290 [inline] #1: ffffc9000358fc40 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_scheduled_works+0xa70/0x1860 kernel/workqueue.c:3397 #2: ffff88802b4f41d8 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1040 [inline] #2: ffff88802b4f41d8 (&dev->mutex){....}-{4:4}, at: hub_event+0x17f/0x4f30 drivers/usb/core/hub.c:5899 #3: ffff88809c7571d8 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1040 [inline] #3: ffff88809c7571d8 (&dev->mutex){....}-{4:4}, at: __device_attach+0x88/0x450 drivers/base/dd.c:1076 #4: ffff88807be2a1a0 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1040 [inline] #4: ffff88807be2a1a0 (&dev->mutex){....}-{4:4}, at: __device_attach+0x88/0x450 drivers/base/dd.c:1076 4 locks held by kworker/1:13/6370: #0: ffff88813fe43140 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3289 [inline] #0: ffff88813fe43140 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0xa35/0x1860 kernel/workqueue.c:3397 #1: ffffc9000334fc40 ((delayed_fput_work).work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3290 [inline] #1: ffffc9000334fc40 ((delayed_fput_work).work){+.+.}-{0:0}, at: process_scheduled_works+0xa70/0x1860 kernel/workqueue.c:3397 #2: ffff888056528dc0 (&sb->s_type->i_mutex_key#13){+.+.}-{4:4}, at: inode_lock include/linux/fs.h:1029 [inline] #2: ffff888056528dc0 (&sb->s_type->i_mutex_key#13){+.+.}-{4:4}, at: __sock_release net/socket.c:721 [inline] #2: ffff888056528dc0 (&sb->s_type->i_mutex_key#13){+.+.}-{4:4}, at: sock_close+0x9b/0x240 net/socket.c:1514 #3: ffffffff8e962f28 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:343 [inline] #3: ffffffff8e962f28 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x38d/0x770 kernel/rcu/tree_exp.h:961 4 locks held by udevd/12568: #0: ffff888058ccb2d8 (&p->lock){+.+.}-{4:4}, at: seq_read_iter+0xb7/0xe10 fs/seq_file.c:183 #1: ffff88807d1b1080 (&of->mutex#2){+.+.}-{4:4}, at: kernfs_seq_start+0x5c/0x420 fs/kernfs/file.c:172 #2: ffff88804d10a788 (kn->active#31){++++}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:80 [inline] #2: ffff88804d10a788 (kn->active#31){++++}-{0:0}, at: kernfs_seq_start+0xb2/0x420 fs/kernfs/file.c:173 #3: ffff8880629e11d8 (&dev->mutex){....}-{4:4}, at: device_lock_interruptible include/linux/device.h:1045 [inline] #3: ffff8880629e11d8 (&dev->mutex){....}-{4:4}, at: manufacturer_show+0x26/0xa0 drivers/usb/core/sysfs.c:142 1 lock held by syz-executor/16250: #0: ffffffff8e962f28 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:311 [inline] #0: ffffffff8e962f28 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x2d0/0x770 kernel/rcu/tree_exp.h:961 6 locks held by kworker/1:0/21595: #0: ffff888021a85d40 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3289 [inline] #0: ffff888021a85d40 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_scheduled_works+0xa35/0x1860 kernel/workqueue.c:3397 #1: ffffc900040efc40 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3290 [inline] #1: ffffc900040efc40 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_scheduled_works+0xa70/0x1860 kernel/workqueue.c:3397 #2: ffff88802b4221d8 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1040 [inline] #2: ffff88802b4221d8 (&dev->mutex){....}-{4:4}, at: hub_event+0x17f/0x4f30 drivers/usb/core/hub.c:5899 #3: ffff8880629e11d8 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1040 [inline] #3: ffff8880629e11d8 (&dev->mutex){....}-{4:4}, at: __device_attach+0x88/0x450 drivers/base/dd.c:1076 #4: ffff8880440c91a0 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1040 [inline] #4: ffff8880440c91a0 (&dev->mutex){....}-{4:4}, at: __device_attach+0x88/0x450 drivers/base/dd.c:1076 #5: ffffffff8e7f9968 (umhelper_sem){++++}-{4:4}, at: usermodehelper_read_trylock+0xfc/0x2c0 kernel/umh.c:214 1 lock held by syz.5.5076/23602: #0: ffff88802b5ad1d8 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1040 [inline] #0: ffff88802b5ad1d8 (&dev->mutex){....}-{4:4}, at: usbdev_open+0x182/0x770 drivers/usb/core/devio.c:1054 ============================================= 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 04/18/2026 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+0x389/0x470 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: 0 Comm: swapper/0 Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026 RIP: 0010:pv_native_safe_halt+0xf/0x20 arch/x86/kernel/paravirt.c:63 Code: cb 7e 02 e9 c3 f8 02 00 cc cc cc 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 66 90 0f 00 2d e3 01 22 00 fb f4 cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc 90 90 90 90 90 RSP: 0018:ffffffff8e607dc0 EFLAGS: 00000246 RAX: 000000000362091b RBX: ffffffff819a845a RCX: 0000000080000001 RDX: 0000000000000001 RSI: ffffffff8dfa4398 RDI: ffffffff8c28b8e0 RBP: ffffffff8e607eb0 R08: ffff8880b86339db R09: 1ffff110170c673b R10: dffffc0000000000 R11: ffffed10170c673c R12: 0000000000000000 R13: 1ffffffff1cd25d8 R14: 0000000000000000 R15: 1ffffffff1cd25d8 FS: 0000000000000000(0000) GS:ffff88812529c000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f5cca5ea2f8 CR3: 000000007bde4000 CR4: 00000000003526f0 Call Trace: arch_safe_halt arch/x86/kernel/process.c:766 [inline] default_idle+0x9/0x20 arch/x86/kernel/process.c:767 default_idle_call+0x72/0xb0 kernel/sched/idle.c:122 cpuidle_idle_call kernel/sched/idle.c:199 [inline] do_idle+0x36a/0x5f0 kernel/sched/idle.c:352 cpu_startup_entry+0x43/0x60 kernel/sched/idle.c:451 rest_init+0x2de/0x300 init/main.c:762 start_kernel+0x38a/0x3e0 init/main.c:1220 x86_64_start_reservations+0x24/0x30 arch/x86/kernel/head64.c:310 x86_64_start_kernel+0x143/0x1c0 arch/x86/kernel/head64.c:291 common_startup_64+0x13e/0x147