INFO: task kworker/1:1:36 blocked for more than 143 seconds. Not tainted 6.11.0-syzkaller-11558-g075dbe9f6e3c #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kworker/1:1 state:D stack:19312 pid:36 tgid:36 ppid:2 flags:0x00004000 Workqueue: usb_hub_wq hub_event Call Trace: context_switch kernel/sched/core.c:5315 [inline] __schedule+0x105f/0x34b0 kernel/sched/core.c:6675 __schedule_loop kernel/sched/core.c:6752 [inline] schedule+0xe7/0x350 kernel/sched/core.c:6767 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6824 rwsem_down_write_slowpath+0x539/0x12a0 kernel/locking/rwsem.c:1178 __down_write_common kernel/locking/rwsem.c:1306 [inline] __down_write kernel/locking/rwsem.c:1315 [inline] down_write+0x1d8/0x200 kernel/locking/rwsem.c:1580 kernfs_remove_by_name_ns+0x87/0x130 fs/kernfs/dir.c:1689 sysfs_remove_file include/linux/sysfs.h:773 [inline] device_remove_file drivers/base/core.c:3064 [inline] device_remove_file+0x28/0x30 drivers/base/core.c:3060 usb_remove_sysfs_intf_files+0x62/0xa0 drivers/usb/core/sysfs.c:1365 usb_bus_notify+0xf7/0x110 drivers/usb/core/usb.c:1047 notifier_call_chain+0xb9/0x410 kernel/notifier.c:93 blocking_notifier_call_chain kernel/notifier.c:388 [inline] blocking_notifier_call_chain+0x69/0xa0 kernel/notifier.c:376 bus_notify+0x56/0x70 drivers/base/bus.c:994 device_del+0x199/0x9f0 drivers/base/core.c:3844 usb_disable_device+0x36c/0x7f0 drivers/usb/core/message.c:1418 usb_disconnect+0x2e1/0x920 drivers/usb/core/hub.c:2304 hub_port_connect drivers/usb/core/hub.c:5361 [inline] hub_port_connect_change drivers/usb/core/hub.c:5661 [inline] port_event drivers/usb/core/hub.c:5821 [inline] hub_event+0x1bed/0x4f40 drivers/usb/core/hub.c:5903 process_one_work+0x9c5/0x1ba0 kernel/workqueue.c:3229 process_scheduled_works kernel/workqueue.c:3310 [inline] worker_thread+0x6c8/0xf00 kernel/workqueue.c:3391 kthread+0x2c1/0x3a0 kernel/kthread.c:389 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 Showing all locks held in the system: 10 locks held by kworker/0:0/8: 1 lock held by khungtaskd/30: #0: ffffffff88ebacc0 ( rcu_read_lock ){....}-{1:2} , at: rcu_lock_acquire include/linux/rcupdate.h:337 [inline] , at: rcu_read_lock include/linux/rcupdate.h:849 [inline] , at: debug_show_all_locks+0x75/0x340 kernel/locking/lockdep.c:6701 6 locks held by kworker/1:1/36: 2 locks held by getty/2607: #0: ffff8881148780a0 (&tty->ldisc_sem){++++}-{0:0} , at: tty_ldisc_ref_wait+0x24/0x80 drivers/tty/tty_ldisc.c:243 #1: ffffc900000432f0 ( &ldata->atomic_read_lock){+.+.}-{3:3} , at: n_tty_read+0xfba/0x1480 drivers/tty/n_tty.c:2211 4 locks held by udevd/5281: 4 locks held by udevd/5290: #0: ffff88811cde50a0 (&p->lock ){+.+.}-{3:3} , at: seq_read_iter+0xd8/0x12b0 fs/seq_file.c:182 #1: ffff888109364088 ( &of->mutex #2 ){+.+.}-{3:3} , at: kernfs_seq_start+0x4d/0x240 fs/kernfs/file.c:154 #2: ffff88811b9afa58 ( kn->active #9 ){++++}-{0:0} , at: kernfs_seq_start+0x71/0x240 fs/kernfs/file.c:155 #3: ffff8881066cc190 ( &dev->mutex ){....}-{3:3} , at: device_lock_interruptible include/linux/device.h:1019 [inline] , at: manufacturer_show+0x26/0xa0 drivers/usb/core/sysfs.c:142 7 locks held by kworker/0:7/12784: 5 locks held by kworker/1:3/13986: #0: ffff8881062c3548 ( (wq_completion)usb_hub_wq ){+.+.}-{0:0} , at: process_one_work+0x129b/0x1ba0 kernel/workqueue.c:3204 #1: ffffc9001082fd80 ( (work_completion)(&hub->events) ){+.+.}-{0:0} , at: process_one_work+0x921/0x1ba0 kernel/workqueue.c:3205 #2: ffff888109b5b190 ( &dev->mutex ){....}-{3:3} , at: device_lock include/linux/device.h:1014 [inline] , at: hub_event+0x1be/0x4f40 drivers/usb/core/hub.c:5849 #3: ffff8881066cc190 ( &dev->mutex ){....}-{3:3} , at: device_lock include/linux/device.h:1014 [inline] , at: __device_attach+0x7f/0x4b0 drivers/base/dd.c:1005 #4: ffff88811174b160 ( &dev->mutex ){....}-{3:3} , at: device_lock include/linux/device.h:1014 [inline] , at: __device_attach+0x7f/0x4b0 drivers/base/dd.c:1005 2 locks held by kworker/u8:1/14168: #0: ffff888100089148 ( (wq_completion)events_unbound ){+.+.}-{0:0} , at: process_one_work+0x129b/0x1ba0 kernel/workqueue.c:3204 #1: ffffc9000fae7d80 ( (work_completion)(&sub_info->work) ){+.+.}-{0:0} , at: process_one_work+0x921/0x1ba0 kernel/workqueue.c:3205 1 lock held by syz.0.2814/14875: #0: ffffffff88ec6638 ( rcu_state.exp_mutex ){+.+.}-{3:3} , at: exp_funnel_lock+0x1a4/0x3b0 kernel/rcu/tree_exp.h:329 1 lock held by syz-executor/14887: #0: ffffffff88ec6638 ( rcu_state.exp_mutex ){+.+.}-{3:3} , at: exp_funnel_lock+0x1a4/0x3b0 kernel/rcu/tree_exp.h:329 2 locks held by kworker/u8:3/14896: #0: ffff8881f583d6d8 ( &rq->__lock ){-.-.}-{2:2} , at: process_one_work+0x129b/0x1ba0 kernel/workqueue.c:3204 #1: ffffc90001bafd80 ( (work_completion)(&sub_info->work) ){+.+.}-{0:0} , at: process_one_work+0x921/0x1ba0 kernel/workqueue.c:3205 2 locks held by kworker/u8:5/14898: #0: ffff888100089148 ( (wq_completion)events_unbound ){+.+.}-{0:0} , at: process_one_work+0x129b/0x1ba0 kernel/workqueue.c:3204 #1: ffffc90001b8fd80 ((work_completion)(&sub_info->work)){+.+.}-{0:0}, at: process_one_work+0x921/0x1ba0 kernel/workqueue.c:3205 1 lock held by modprobe/15390: ============================================= NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 30 Comm: khungtaskd Not tainted 6.11.0-syzkaller-11558-g075dbe9f6e3c #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024 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:162 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:223 [inline] watchdog+0xf0c/0x1240 kernel/hung_task.c:379 kthread+0x2c1/0x3a0 kernel/kthread.c:389 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 4935 Comm: kworker/0:4 Not tainted 6.11.0-syzkaller-11558-g075dbe9f6e3c #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024 Workqueue: events dvb_usb_read_remote_control RIP: 0010:io_serial_out+0x8f/0xb0 drivers/tty/serial/8250/8250_port.c:413 Code: 48 8d 7d 40 44 89 e1 48 b8 00 00 00 00 00 fc ff df 48 89 fa d3 e3 48 c1 ea 03 80 3c 02 00 75 1c 66 03 5d 40 44 89 e8 89 da ee <5b> 5d 41 5c 41 5d c3 cc cc cc cc e8 c1 ea 0d ff eb a0 e8 4a eb 0d RSP: 0000:ffffc900024af7c0 EFLAGS: 00000002 RAX: 0000000000000031 RBX: 00000000000003f8 RCX: 0000000000000000 RDX: 00000000000003f8 RSI: ffffffff82a04085 RDI: ffffffff9362a660 RBP: ffffffff9362a620 R08: 0000000000000001 R09: 000000000000001f R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000 R13: 0000000000000031 R14: ffffffff82a04020 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff8881f5800000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f6b9ccead08 CR3: 00000001236ec000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: serial_out drivers/tty/serial/8250/8250.h:142 [inline] serial8250_console_fifo_write drivers/tty/serial/8250/8250_port.c:3322 [inline] serial8250_console_write+0xf9e/0x17c0 drivers/tty/serial/8250/8250_port.c:3393 console_emit_next_record kernel/printk/printk.c:3092 [inline] console_flush_all+0x800/0xc60 kernel/printk/printk.c:3180 __console_flush_and_unlock kernel/printk/printk.c:3239 [inline] console_unlock+0xd9/0x210 kernel/printk/printk.c:3279 vprintk_emit+0x424/0x6f0 kernel/printk/printk.c:2407 vprintk+0x7f/0xa0 kernel/printk/printk_safe.c:68 _printk+0xc8/0x100 kernel/printk/printk.c:2432 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+0x9c5/0x1ba0 kernel/workqueue.c:3229 process_scheduled_works kernel/workqueue.c:3310 [inline] worker_thread+0x6c8/0xf00 kernel/workqueue.c:3391 kthread+0x2c1/0x3a0 kernel/kthread.c:389 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244