INFO: task kworker/0:2:183 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kworker/0:2 state:D stack:21224 pid:183 tgid:183 ppid:2 task_flags:0x4208160 flags:0x00080000 Workqueue: usb_hub_wq hub_event 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 hub_port_connect drivers/usb/core/hub.c:5465 [inline] hub_port_connect_change drivers/usb/core/hub.c:5707 [inline] port_event drivers/usb/core/hub.c:5871 [inline] hub_event+0x2182/0x4ef0 drivers/usb/core/hub.c:5953 process_one_work+0x93a/0x15a0 kernel/workqueue.c:3261 process_scheduled_works kernel/workqueue.c:3344 [inline] worker_thread+0x9b0/0xee0 kernel/workqueue.c:3425 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 Showing all locks held in the system: 6 locks held by kworker/1:0/24: #0: ffff88801e2a9948 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work+0x841/0x15a0 kernel/workqueue.c:3236 #1: ffffc900001e7b80 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work+0x868/0x15a0 kernel/workqueue.c:3237 #2: ffff888028b01198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:895 [inline] #2: ffff888028b01198 (&dev->mutex){....}-{4:4}, at: hub_event+0x187/0x4ef0 drivers/usb/core/hub.c:5899 #3: ffff888028ada518 (&port_dev->status_lock){+.+.}-{4:4}, at: usb_lock_port drivers/usb/core/hub.c:3252 [inline] #3: ffff888028ada518 (&port_dev->status_lock){+.+.}-{4:4}, at: hub_port_connect drivers/usb/core/hub.c:5464 [inline] #3: ffff888028ada518 (&port_dev->status_lock){+.+.}-{4:4}, at: hub_port_connect_change drivers/usb/core/hub.c:5707 [inline] #3: ffff888028ada518 (&port_dev->status_lock){+.+.}-{4:4}, at: port_event drivers/usb/core/hub.c:5871 [inline] #3: ffff888028ada518 (&port_dev->status_lock){+.+.}-{4:4}, at: hub_event+0x215a/0x4ef0 drivers/usb/core/hub.c:5953 #4: ffff888027336468 (hcd->address0_mutex){+.+.}-{4:4}, at: hub_port_connect drivers/usb/core/hub.c:5465 [inline] #4: ffff888027336468 (hcd->address0_mutex){+.+.}-{4:4}, at: hub_port_connect_change drivers/usb/core/hub.c:5707 [inline] #4: ffff888027336468 (hcd->address0_mutex){+.+.}-{4:4}, at: port_event drivers/usb/core/hub.c:5871 [inline] #4: ffff888027336468 (hcd->address0_mutex){+.+.}-{4:4}, at: hub_event+0x2182/0x4ef0 drivers/usb/core/hub.c:5953 #5: ffffffff8efde190 (ehci_cf_port_reset_rwsem){.+.+}-{4:4}, at: hub_port_reset+0x14e/0x1850 drivers/usb/core/hub.c:3067 1 lock held by khungtaskd/31: #0: ffffffff8e3419e0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8e3419e0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline] #0: ffffffff8e3419e0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775 5 locks held by kworker/u8:2/36: 5 locks held by kworker/0:2/183: #0: ffff88801e2a9948 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work+0x841/0x15a0 kernel/workqueue.c:3236 #1: ffffc90002f37b80 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work+0x868/0x15a0 kernel/workqueue.c:3237 #2: ffff8880297b3198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:895 [inline] #2: ffff8880297b3198 (&dev->mutex){....}-{4:4}, at: hub_event+0x187/0x4ef0 drivers/usb/core/hub.c:5899 #3: ffff8880297b6518 (&port_dev->status_lock){+.+.}-{4:4}, at: usb_lock_port drivers/usb/core/hub.c:3252 [inline] #3: ffff8880297b6518 (&port_dev->status_lock){+.+.}-{4:4}, at: hub_port_connect drivers/usb/core/hub.c:5464 [inline] #3: ffff8880297b6518 (&port_dev->status_lock){+.+.}-{4:4}, at: hub_port_connect_change drivers/usb/core/hub.c:5707 [inline] #3: ffff8880297b6518 (&port_dev->status_lock){+.+.}-{4:4}, at: port_event drivers/usb/core/hub.c:5871 [inline] #3: ffff8880297b6518 (&port_dev->status_lock){+.+.}-{4:4}, at: hub_event+0x215a/0x4ef0 drivers/usb/core/hub.c:5953 #4: ffff8880286dbe68 (hcd->address0_mutex){+.+.}-{4:4}, at: hub_port_connect drivers/usb/core/hub.c:5465 [inline] #4: ffff8880286dbe68 (hcd->address0_mutex){+.+.}-{4:4}, at: hub_port_connect_change drivers/usb/core/hub.c:5707 [inline] #4: ffff8880286dbe68 (hcd->address0_mutex){+.+.}-{4:4}, at: port_event drivers/usb/core/hub.c:5871 [inline] #4: ffff8880286dbe68 (hcd->address0_mutex){+.+.}-{4:4}, at: hub_event+0x2182/0x4ef0 drivers/usb/core/hub.c:5953 2 locks held by getty/5586: #0: ffff8880346580a0 (&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 6 locks held by kworker/1:8/12913: #0: ffff88801e2a9948 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work+0x841/0x15a0 kernel/workqueue.c:3236 #1: ffffc900033f7b80 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work+0x868/0x15a0 kernel/workqueue.c:3237 #2: ffff888145b77198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:895 [inline] #2: ffff888145b77198 (&dev->mutex){....}-{4:4}, at: hub_event+0x187/0x4ef0 drivers/usb/core/hub.c:5899 #3: ffff888033abc198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:895 [inline] #3: ffff888033abc198 (&dev->mutex){....}-{4:4}, at: __device_attach+0x88/0x430 drivers/base/dd.c:1006 #4: ffff88802dbc6160 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:895 [inline] #4: ffff88802dbc6160 (&dev->mutex){....}-{4:4}, at: __device_attach+0x88/0x430 drivers/base/dd.c:1006 #5: ffff888142381a68 ( hcd->bandwidth_mutex){+.+.}-{4:4}, at: usb_set_interface+0x353/0x1460 drivers/usb/core/message.c:1564 4 locks held by udevd/15321: #0: ffff88803388eb08 (&p->lock){+.+.}-{4:4}, at: seq_read_iter+0xb7/0xe20 fs/seq_file.c:182 #1: ffff88807556f888 (&of->mutex#2){+.+.}-{4:4}, at: kernfs_seq_start+0x5c/0x420 fs/kernfs/file.c:172 #2: ffffffff8e9ff538 (tomoyo_ss){.+.+}-{0:0}, at: srcu_lock_acquire include/linux/srcu.h:185 [inline] #2: ffffffff8e9ff538 (tomoyo_ss){.+.+}-{0:0}, at: srcu_read_lock include/linux/srcu.h:277 [inline] #2: ffffffff8e9ff538 (tomoyo_ss){.+.+}-{0:0}, at: tomoyo_read_lock security/tomoyo/common.h:1110 [inline] #2: ffffffff8e9ff538 (tomoyo_ss){.+.+}-{0:0}, at: tomoyo_path_number_perm+0x1bc/0x5a0 security/tomoyo/file.c:722 #3: ffffffff8e016848 (rename_lock.seqcount){+.+.}-{0:0}, at: read_seqbegin_or_lock include/linux/seqlock.h:1130 [inline] #3: ffffffff8e016848 (rename_lock.seqcount){+.+.}-{0:0}, at: prepend_path+0x22a/0x830 fs/d_path.c:171 5 locks held by kworker/0:8/17550: #0: ffff88801e2a9948 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work+0x841/0x15a0 kernel/workqueue.c:3236 #1: ffffc90003317b80 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work+0x868/0x15a0 kernel/workqueue.c:3237 #2: ffff888146f35198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:895 [inline] #2: ffff888146f35198 (&dev->mutex){....}-{4:4}, at: hub_event+0x187/0x4ef0 drivers/usb/core/hub.c:5899 #3: ffff8880297a0518 (&port_dev->status_lock){+.+.}-{4:4}, at: usb_lock_port drivers/usb/core/hub.c:3252 [inline] #3: ffff8880297a0518 (&port_dev->status_lock){+.+.}-{4:4}, at: hub_port_connect drivers/usb/core/hub.c:5464 [inline] #3: ffff8880297a0518 (&port_dev->status_lock){+.+.}-{4:4}, at: hub_port_connect_change drivers/usb/core/hub.c:5707 [inline] #3: ffff8880297a0518 (&port_dev->status_lock){+.+.}-{4:4}, at: port_event drivers/usb/core/hub.c:5871 [inline] #3: ffff8880297a0518 (&port_dev->status_lock){+.+.}-{4:4}, at: hub_event+0x215a/0x4ef0 drivers/usb/core/hub.c:5953 #4: ffff8880286dbe68 (hcd->address0_mutex){+.+.}-{4:4}, at: hub_port_connect drivers/usb/core/hub.c:5465 [inline] #4: ffff8880286dbe68 (hcd->address0_mutex){+.+.}-{4:4}, at: hub_port_connect_change drivers/usb/core/hub.c:5707 [inline] #4: ffff8880286dbe68 (hcd->address0_mutex){+.+.}-{4:4}, at: port_event drivers/usb/core/hub.c:5871 [inline] #4: ffff8880286dbe68 (hcd->address0_mutex){+.+.}-{4:4}, at: hub_event+0x2182/0x4ef0 drivers/usb/core/hub.c:5953 ============================================= NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 31 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT(full) 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: 0 PID: 21166 Comm: syz.6.4160 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 RIP: 0010:__lock_acquire+0x85b/0x2cf0 kernel/locking/lockdep.c:-1 Code: 29 c5 89 c1 c1 c1 04 31 e9 01 d8 29 cb 89 ca c1 c2 06 31 da 01 c1 29 d0 89 d6 c1 c6 08 31 c6 01 ca 29 f1 89 f3 c1 c3 10 31 cb <01> d6 29 da 89 dd c1 c5 13 31 d5 01 f3 29 ee 01 eb c1 c5 04 31 f5 RSP: 0018:ffffc90000a08c18 EFLAGS: 00000086 RAX: 0000000000001c6f RBX: 00000000938c941e RCX: 00000000001c6bfd RDX: 00000000ffffe31c RSI: 00000000ffe39390 RDI: ffff88802aba5b80 RBP: 0000000000000070 R08: ffffffff81af4c6a R09: ffff8880b8728258 R10: dffffc0000000000 R11: ffffffff81af4b70 R12: ffff88802aba66b0 R13: ffff88802aba66b0 R14: ffff88802aba5b80 R15: 0000000000000000 FS: 00007f6a8e08a6c0(0000) GS:ffff888125afd000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000200000001000 CR3: 0000000033cbe000 CR4: 00000000003526f0 DR0: ffffffffffffffff DR1: 00000000000001f8 DR2: 00000000000001ff DR3: ffffffffefffff15 DR6: 00000000ffff0ff0 DR7: 0000000000000400 Call Trace: lock_acquire+0x117/0x340 kernel/locking/lockdep.c:5868 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0xa7/0xf0 kernel/locking/spinlock.c:162 hrtimer_interrupt+0xfa/0xaa0 kernel/time/hrtimer.c:1884 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1045 [inline] __sysvec_apic_timer_interrupt+0x102/0x3e0 arch/x86/kernel/apic/apic.c:1062 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1056 [inline] sysvec_apic_timer_interrupt+0xa1/0xc0 arch/x86/kernel/apic/apic.c:1056 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697 RIP: 0010:console_trylock_spinning kernel/printk/printk.c:2037 [inline] RIP: 0010:vprintk_emit+0x4d0/0x5f0 kernel/printk/printk.c:2425 Code: 0f 84 34 ff ff ff e8 4f 62 20 00 fb eb 44 e8 47 62 20 00 e8 c2 10 c2 09 4d 85 f6 74 94 e8 38 62 20 00 fb 48 c7 c7 a0 58 33 8e <31> f6 ba 01 00 00 00 31 c9 41 b8 01 00 00 00 45 31 c9 53 e8 28 26 RSP: 0018:ffffc900051a7620 EFLAGS: 00000283 RAX: ffffffff81a190f8 RBX: ffffffff81a18f51 RCX: 0000000000080000 RDX: ffffc90014826000 RSI: 0000000000025490 RDI: ffffffff8e3358a0 RBP: ffffc900051a7730 R08: ffffffff8fc2fb77 R09: 1ffffffff1f85f6e R10: dffffc0000000000 R11: fffffbfff1f85f6f R12: 0000000000000000 R13: 0000000000000019 R14: 0000000000000200 R15: 1ffff92000a34ec8 _printk+0xcf/0x120 kernel/printk/printk.c:2451 logfc+0x401/0x4f0 fs/fs_context.c:-1 fs_param_bad_value fs/fs_parser.c:196 [inline] fs_param_is_u32+0x1aa/0x230 fs/fs_parser.c:-1 __fs_parse+0x3bc/0x730 fs/fs_parser.c:129 fs_parse include/linux/fs_parser.h:76 [inline] v9fs_parse_param+0xd2/0xf80 fs/9p/v9fs.c:205 vfs_parse_fs_param+0x1a9/0x420 fs/fs_context.c:146 vfs_parse_fs_qstr fs/fs_context.c:187 [inline] vfs_parse_fs_string include/linux/fs_context.h:142 [inline] vfs_parse_monolithic_sep+0x25d/0x320 fs/fs_context.c:227 do_new_mount+0x2cb/0xa10 fs/namespace.c:3708 do_mount fs/namespace.c:4035 [inline] __do_sys_mount fs/namespace.c:4224 [inline] __se_sys_mount+0x313/0x410 fs/namespace.c:4201 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: 0033:0x7f6a8d18f749 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f6a8e08a038 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5 RAX: ffffffffffffffda RBX: 00007f6a8d3e5fa0 RCX: 00007f6a8d18f749 RDX: 0000200000000040 RSI: 00002000000000c0 RDI: 0000000000000000 RBP: 00007f6a8d213f91 R08: 0000200000000300 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f6a8d3e6038 R14: 00007f6a8d3e5fa0 R15: 00007ffd53912928