INFO: task kworker/1:0:23 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kworker/1:0 state:D stack:21944 pid:23 tgid:23 ppid:2 task_flags:0x4208060 flags:0x00004000 Workqueue: usb_hub_wq hub_event Call Trace: context_switch kernel/sched/core.c:5357 [inline] __schedule+0x12fc/0x3b90 kernel/sched/core.c:6961 __schedule_loop kernel/sched/core.c:7043 [inline] schedule+0xe7/0x3a0 kernel/sched/core.c:7058 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7115 rwsem_down_write_slowpath+0x524/0x1310 kernel/locking/rwsem.c:1185 __down_write_common kernel/locking/rwsem.c:1317 [inline] __down_write kernel/locking/rwsem.c:1326 [inline] down_write+0x1d6/0x200 kernel/locking/rwsem.c:1591 kernfs_add_one+0x38/0x840 fs/kernfs/dir.c:791 kernfs_create_link+0x1a9/0x240 fs/kernfs/symlink.c:48 sysfs_do_create_link_sd+0x90/0x140 fs/sysfs/symlink.c:44 sysfs_do_create_link fs/sysfs/symlink.c:80 [inline] sysfs_create_link+0x61/0xc0 fs/sysfs/symlink.c:92 usb_new_device+0xec4/0x1a60 drivers/usb/core/hub.c:2706 hub_port_connect drivers/usb/core/hub.c:5566 [inline] hub_port_connect_change drivers/usb/core/hub.c:5706 [inline] port_event drivers/usb/core/hub.c:5870 [inline] hub_event+0x2fce/0x5060 drivers/usb/core/hub.c:5952 process_one_work+0x9cc/0x1b70 kernel/workqueue.c:3236 process_scheduled_works kernel/workqueue.c:3319 [inline] worker_thread+0x6c8/0xf10 kernel/workqueue.c:3400 kthread+0x3c5/0x780 kernel/kthread.c:463 ret_from_fork+0x5b6/0x6c0 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 INFO: task syz.2.2207:13138 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.2.2207 state:D stack:28640 pid:13138 tgid:13132 ppid:2965 task_flags:0x400040 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:5357 [inline] __schedule+0x12fc/0x3b90 kernel/sched/core.c:6961 __schedule_loop kernel/sched/core.c:7043 [inline] schedule+0xe7/0x3a0 kernel/sched/core.c:7058 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7115 rwsem_down_write_slowpath+0x524/0x1310 kernel/locking/rwsem.c:1185 __down_write_common kernel/locking/rwsem.c:1317 [inline] __down_write kernel/locking/rwsem.c:1326 [inline] down_write+0x1d6/0x200 kernel/locking/rwsem.c:1591 kernfs_add_one+0x38/0x840 fs/kernfs/dir.c:791 kernfs_create_dir_ns+0xfc/0x1a0 fs/kernfs/dir.c:1093 sysfs_create_dir_ns+0x13a/0x2b0 fs/sysfs/dir.c:59 create_dir lib/kobject.c:73 [inline] kobject_add_internal+0x2c4/0x9b0 lib/kobject.c:240 kobject_add_varg lib/kobject.c:374 [inline] kobject_init_and_add+0x11b/0x190 lib/kobject.c:457 bus_add_driver+0x186/0x690 drivers/base/bus.c:671 driver_register+0x15c/0x4b0 drivers/base/driver.c:249 usb_gadget_register_driver_owner+0x132/0x330 drivers/usb/gadget/udc/core.c:1700 raw_ioctl_run drivers/usb/gadget/legacy/raw_gadget.c:595 [inline] raw_ioctl+0x17d0/0x2c30 drivers/usb/gadget/legacy/raw_gadget.c:1306 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:598 [inline] __se_sys_ioctl fs/ioctl.c:584 [inline] __x64_sys_ioctl+0x18b/0x210 fs/ioctl.c:584 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xcd/0x4b0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fe95c2fe7ab RSP: 002b:00007fe95ad3bf10 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 0000000000000007 RCX: 00007fe95c2fe7ab RDX: 0000000000000000 RSI: 0000000000005501 RDI: 0000000000000007 RBP: 00007fe95ad3cfe0 R08: 0000000000000000 R09: 00322e6364755f79 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fe95ad3bfb0 R14: 0000200000000000 R15: 00007fe95c672d28 Showing all locks held in the system: 3 locks held by kworker/1:0/23: 1 lock held by khungtaskd/30: #0: ffffffff892c7360 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff892c7360 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline] #0: ffffffff892c7360 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x36/0x1c0 kernel/locking/lockdep.c:6775 2 locks held by getty/2911: #0: ffff8881123720a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x24/0x80 drivers/tty/tty_ldisc.c:243 #1: ffffc900000432f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x41b/0x14f0 drivers/tty/n_tty.c:2222 1 lock held by syz-executor/2957: #0: ffff888100ac5188 (&root->kernfs_rwsem){++++}-{4:4}, at: kernfs_dop_revalidate+0x397/0x740 fs/kernfs/dir.c:1162 1 lock held by syz-executor/2958: #0: ffff888100ac5188 (&root->kernfs_rwsem){++++}-{4:4}, at: kernfs_dop_revalidate+0x397/0x740 fs/kernfs/dir.c:1162 1 lock held by syz-executor/2959: #0: ffff888100ac5188 (&root->kernfs_rwsem){++++}-{4:4}, at: kernfs_dop_revalidate+0x397/0x740 fs/kernfs/dir.c:1162 1 lock held by syz-executor/2960: #0: ffff888100ac5188 (&root->kernfs_rwsem){++++}-{4:4} , at: kernfs_dop_revalidate+0x397/0x740 fs/kernfs/dir.c:1162 1 lock held by syz-executor/2965: #0: ffff888100ac5188 ( &root->kernfs_rwsem){++++}-{4:4} , at: kernfs_dop_revalidate+0x397/0x740 fs/kernfs/dir.c:1162 6 locks held by kworker/0:3/5214: 1 lock held by udevd/7731: #0: ffff888100ac5188 ( &root->kernfs_rwsem ){++++}-{4:4} , at: kernfs_dop_revalidate+0xa5/0x740 fs/kernfs/dir.c:1180 7 locks held by kworker/0:6/8095: 4 locks held by kworker/0:7/9689: 5 locks held by kworker/0:5/12192: #0: ffff8881066f7948 ( (wq_completion)usb_hub_wq ){+.+.}-{0:0}, at: process_one_work+0x12a2/0x1b70 kernel/workqueue.c:3211 #1: ffffc9001261fd10 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work+0x929/0x1b70 kernel/workqueue.c:3212 #2: ffff88810b3d5198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:911 [inline] ffff88810b3d5198 (&dev->mutex){....}-{4:4}, at: hub_event+0x1be/0x5060 drivers/usb/core/hub.c:5898 #3: ffff888119312198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:911 [inline] #3: ffff888119312198 (&dev->mutex){....}-{4:4}, at: __device_attach+0x7e/0x4b0 drivers/base/dd.c:1006 #4: ffff888100ac5188 (&root->kernfs_rwsem){++++}-{4:4}, at: kernfs_add_one+0x38/0x840 fs/kernfs/dir.c:791 1 lock held by syz-executor/13151: #0: ffff888100ac5188 ( &root->kernfs_rwsem){++++}-{4:4}, at: kernfs_dop_revalidate+0xa5/0x740 fs/kernfs/dir.c:1180 1 lock held by syz-executor/13152: #0: ffff888100ac5188 (&root->kernfs_rwsem ){++++}-{4:4} , at: kernfs_dop_revalidate+0xa5/0x740 fs/kernfs/dir.c:1180 1 lock held by syz-executor/13153: #0: ffff888100ac5188 (&root->kernfs_rwsem ){++++}-{4:4} , at: kernfs_dop_revalidate+0xa5/0x740 fs/kernfs/dir.c:1180 1 lock held by syz-executor/13154: #0: ffff888100ac5188 ( &root->kernfs_rwsem){++++}-{4:4} , at: kernfs_dop_revalidate+0xa5/0x740 fs/kernfs/dir.c:1180 1 lock held by syz-executor/13155: #0: ffff888100ac5188 (&root->kernfs_rwsem){++++}-{4:4} , at: kernfs_dop_revalidate+0xa5/0x740 fs/kernfs/dir.c:1180 ============================================= NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 30 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT(voluntary) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025 Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:120 nmi_cpu_backtrace+0x27b/0x390 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x29c/0x300 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:160 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:328 [inline] watchdog+0xf0e/0x1260 kernel/hung_task.c:491 kthread+0x3c5/0x780 kernel/kthread.c:463 ret_from_fork+0x5b6/0x6c0 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Sending NMI from CPU 1 to CPUs 0: gspca_pac7302 3-1:0.0: URB error -71, resubmitting NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 8095 Comm: kworker/0:6 Not tainted syzkaller #0 PREEMPT(voluntary) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025 Workqueue: events dvb_usb_read_remote_control RIP: 0010:check_kcov_mode kernel/kcov.c:183 [inline] RIP: 0010:__sanitizer_cov_trace_pc+0x37/0x70 kernel/kcov.c:217 Code: 27 14 0b 65 8b 05 c9 27 14 0b a9 00 01 ff 00 74 1d f6 c4 01 74 43 a9 00 00 0f 00 75 3c a9 00 00 f0 00 75 35 8b 82 74 15 00 00 <85> c0 74 2b 8b 82 50 15 00 00 83 f8 02 75 20 48 8b 8a 58 15 00 00 RSP: 0018:ffffc900000076c0 EFLAGS: 00000046 RAX: 0000000000000000 RBX: ffffffff939c13e0 RCX: dffffc0000000000 RDX: ffff888122c70000 RSI: ffffffff82db36ef RDI: 0000000000000007 RBP: 000000000000001d R08: 0000000000000007 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: ffffffff93b7d450 R13: 0000000000000010 R14: ffffffff93b7d1a0 R15: 0000000000000001 FS: 0000000000000000(0000) GS:ffff888268efe000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f0612311fe0 CR3: 00000000090a4000 CR4: 00000000003506f0 Call Trace: fifo_wait_for_lsr drivers/tty/serial/8250/8250_port.c:3287 [inline] serial8250_console_fifo_write drivers/tty/serial/8250/8250_port.c:3311 [inline] serial8250_console_write+0xf3f/0x1890 drivers/tty/serial/8250/8250_port.c:3396 console_emit_next_record kernel/printk/printk.c:3138 [inline] console_flush_all+0x7fe/0xc60 kernel/printk/printk.c:3226 __console_flush_and_unlock kernel/printk/printk.c:3285 [inline] console_unlock+0xd8/0x210 kernel/printk/printk.c:3325 vprintk_emit+0x418/0x6d0 kernel/printk/printk.c:2450 _printk+0xc7/0x100 kernel/printk/printk.c:2475 int_irq+0x1b7/0x270 drivers/media/usb/gspca/gspca.c:104 __usb_hcd_giveback_urb+0x388/0x610 drivers/usb/core/hcd.c:1661 usb_hcd_giveback_urb+0x39b/0x450 drivers/usb/core/hcd.c:1745 dummy_timer+0x1814/0x3a30 drivers/usb/gadget/udc/dummy_hcd.c:1995 __run_hrtimer kernel/time/hrtimer.c:1761 [inline] __hrtimer_run_queues+0x1ff/0xad0 kernel/time/hrtimer.c:1825 hrtimer_run_softirq+0x17d/0x350 kernel/time/hrtimer.c:1842 handle_softirqs+0x208/0x8d0 kernel/softirq.c:579 __do_softirq kernel/softirq.c:613 [inline] invoke_softirq kernel/softirq.c:453 [inline] __irq_exit_rcu+0xfa/0x160 kernel/softirq.c:680 irq_exit_rcu+0x9/0x30 kernel/softirq.c:696 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1050 [inline] sysvec_apic_timer_interrupt+0x90/0xb0 arch/x86/kernel/apic/apic.c:1050 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:console_flush_all+0x9a2/0xc60 kernel/printk/printk.c:3227 Code: 00 e8 92 86 28 00 9c 5b 81 e3 00 02 00 00 31 ff 48 89 de e8 b0 a6 20 00 48 85 db 0f 85 55 01 00 00 e8 32 ab 20 00 fb 4c 89 e0 <48> c1 e8 03 42 80 3c 38 00 0f 84 11 ff ff ff 4c 89 e7 e8 97 d9 7e RSP: 0018:ffffc900135ff8c0 EFLAGS: 00000293 RAX: ffffffff897db338 RBX: 0000000000000000 RCX: ffffffff815d4d10 RDX: ffff888122c70000 RSI: ffffffff815d4d1e RDI: 0000000000000007 RBP: 0000000000000001 R08: 0000000000000007 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: ffffffff897db338 R13: ffffffff897db2e0 R14: ffffc900135ff950 R15: dffffc0000000000 __console_flush_and_unlock kernel/printk/printk.c:3285 [inline] console_unlock+0xd8/0x210 kernel/printk/printk.c:3325 vprintk_emit+0x418/0x6d0 kernel/printk/printk.c:2450 _printk+0xc7/0x100 kernel/printk/printk.c:2475 m920x_read drivers/media/usb/dvb-usb/m920x.c:40 [inline] m920x_rc_core_query+0x2d7/0x500 drivers/media/usb/dvb-usb/m920x.c:229 dvb_usb_read_remote_control+0xda/0x1c0 drivers/media/usb/dvb-usb/dvb-usb-remote.c:261 process_one_work+0x9cc/0x1b70 kernel/workqueue.c:3236 process_scheduled_works kernel/workqueue.c:3319 [inline] worker_thread+0x6c8/0xf10 kernel/workqueue.c:3400 kthread+0x3c5/0x780 kernel/kthread.c:463 ret_from_fork+0x5b6/0x6c0 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245