INFO: task udevd:2839 blocked for more than 143 seconds. Not tainted 6.15.0-rc1-syzkaller-00068-g169263214645 #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:udevd state:D stack:24536 pid:2839 tgid:2839 ppid:1 task_flags:0x400140 flags:0x00000002 Call Trace: context_switch kernel/sched/core.c:5382 [inline] __schedule+0x132a/0x3b00 kernel/sched/core.c:6767 __schedule_loop kernel/sched/core.c:6845 [inline] schedule+0xe7/0x3a0 kernel/sched/core.c:6860 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6917 rwsem_down_read_slowpath+0x62f/0xb60 kernel/locking/rwsem.c:1084 __down_read_common kernel/locking/rwsem.c:1248 [inline] __down_read kernel/locking/rwsem.c:1261 [inline] down_read+0xef/0x480 kernel/locking/rwsem.c:1526 kernfs_dop_revalidate+0xa5/0x740 fs/kernfs/dir.c:1178 d_revalidate fs/namei.c:929 [inline] d_revalidate fs/namei.c:925 [inline] lookup_fast+0x263/0x610 fs/namei.c:1768 walk_component+0x5b/0x5b0 fs/namei.c:2124 link_path_walk.part.0.constprop.0+0x682/0xd60 fs/namei.c:2493 link_path_walk fs/namei.c:2423 [inline] path_lookupat+0x91/0x780 fs/namei.c:2649 filename_lookup+0x224/0x5f0 fs/namei.c:2679 do_readlinkat+0xce/0x3a0 fs/stat.c:564 __do_sys_readlink fs/stat.c:601 [inline] __se_sys_readlink fs/stat.c:598 [inline] __x64_sys_readlink+0x78/0xc0 fs/stat.c:598 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xcd/0x260 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7ffbb9536d47 RSP: 002b:00007fff5fead068 EFLAGS: 00000246 ORIG_RAX: 0000000000000059 RAX: ffffffffffffffda RBX: 00007fff5fead078 RCX: 00007ffbb9536d47 RDX: 0000000000000400 RSI: 00007fff5fead078 RDI: 00007fff5fead558 RBP: 0000000000000400 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007fff5fead558 R13: 00007fff5fead4c8 R14: 00005560f89d42c0 R15: 0000000000000000 INFO: task udevd:5383 blocked for more than 171 seconds. Not tainted 6.15.0-rc1-syzkaller-00068-g169263214645 #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:udevd state:D stack:24728 pid:5383 tgid:5383 ppid:2839 task_flags:0x400140 flags:0x00004002 Call Trace: context_switch kernel/sched/core.c:5382 [inline] __schedule+0x132a/0x3b00 kernel/sched/core.c:6767 __schedule_loop kernel/sched/core.c:6845 [inline] schedule+0xe7/0x3a0 kernel/sched/core.c:6860 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6917 __mutex_lock_common kernel/locking/mutex.c:678 [inline] __mutex_lock+0x6c7/0xb90 kernel/locking/mutex.c:746 device_lock include/linux/device.h:922 [inline] uevent_show+0x187/0x3b0 drivers/base/core.c:2730 dev_attr_show+0x53/0xe0 drivers/base/core.c:2424 sysfs_kf_seq_show+0x213/0x3e0 fs/sysfs/file.c:65 seq_read_iter+0x506/0x12b0 fs/seq_file.c:230 kernfs_fop_read_iter+0x422/0x5a0 fs/kernfs/file.c:279 new_sync_read fs/read_write.c:489 [inline] vfs_read+0x8c8/0xc70 fs/read_write.c:570 ksys_read+0x12a/0x240 fs/read_write.c:713 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xcd/0x260 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7ffbb9535b6a RSP: 002b:00007fff5fea6088 EFLAGS: 00000246 ORIG_RAX: 0000000000000000 RAX: ffffffffffffffda RBX: 00005560f89f2c90 RCX: 00007ffbb9535b6a RDX: 0000000000001000 RSI: 00005560f8ab9ba0 RDI: 0000000000000008 RBP: 00005560f89f2c90 R08: 0000000000000008 R09: 0000000000000000 R10: 000000000000010f R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000003fff R14: 00007fff5fea6568 R15: 000000000000000a INFO: task udevd:5383 is blocked on a mutex likely owned by task kworker/0:0:9. task:kworker/0:0 state:D stack:21288 pid:9 tgid:9 ppid:2 task_flags:0x4208060 flags:0x00004000 Workqueue: usb_hub_wq hub_event Call Trace: context_switch kernel/sched/core.c:5382 [inline] __schedule+0x132a/0x3b00 kernel/sched/core.c:6767 __schedule_loop kernel/sched/core.c:6845 [inline] schedule+0xe7/0x3a0 kernel/sched/core.c:6860 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6917 __mutex_lock_common kernel/locking/mutex.c:678 [inline] __mutex_lock+0x6c7/0xb90 kernel/locking/mutex.c:746 uevent_net_broadcast_untagged lib/kobject_uevent.c:317 [inline] kobject_uevent_net_broadcast lib/kobject_uevent.c:410 [inline] kobject_uevent_env+0xb36/0x1870 lib/kobject_uevent.c:608 device_add+0x10dd/0x1a70 drivers/base/core.c:3647 rc_register_device+0xe1a/0x1bd0 drivers/media/rc/rc-main.c:1934 rc_core_dvb_usb_remote_init drivers/media/usb/dvb-usb/dvb-usb-remote.c:289 [inline] dvb_usb_remote_init+0xe47/0x15e0 drivers/media/usb/dvb-usb/dvb-usb-remote.c:337 dvb_usb_init drivers/media/usb/dvb-usb/dvb-usb-init.c:190 [inline] dvb_usb_device_init+0x1786/0x2070 drivers/media/usb/dvb-usb/dvb-usb-init.c:310 usb_probe_interface+0x300/0x9c0 drivers/usb/core/driver.c:396 call_driver_probe drivers/base/dd.c:579 [inline] really_probe+0x23e/0xa90 drivers/base/dd.c:658 __driver_probe_device+0x1de/0x440 drivers/base/dd.c:800 driver_probe_device+0x4c/0x1b0 drivers/base/dd.c:830 __device_attach_driver+0x1df/0x310 drivers/base/dd.c:958 bus_for_each_drv+0x156/0x1e0 drivers/base/bus.c:462 __device_attach+0x1e4/0x4b0 drivers/base/dd.c:1030 bus_probe_device+0x17f/0x1c0 drivers/base/bus.c:537 device_add+0x1148/0x1a70 drivers/base/core.c:3666 usb_set_configuration+0x1187/0x1e20 drivers/usb/core/message.c:2210 usb_generic_driver_probe+0xb1/0x110 drivers/usb/core/generic.c:250 usb_probe_device+0xec/0x3e0 drivers/usb/core/driver.c:291 call_driver_probe drivers/base/dd.c:579 [inline] really_probe+0x23e/0xa90 drivers/base/dd.c:658 __driver_probe_device+0x1de/0x440 drivers/base/dd.c:800 driver_probe_device+0x4c/0x1b0 drivers/base/dd.c:830 __device_attach_driver+0x1df/0x310 drivers/base/dd.c:958 bus_for_each_drv+0x156/0x1e0 drivers/base/bus.c:462 __device_attach+0x1e4/0x4b0 drivers/base/dd.c:1030 bus_probe_device+0x17f/0x1c0 drivers/base/bus.c:537 device_add+0x1148/0x1a70 drivers/base/core.c:3666 usb_new_device+0xd07/0x1a20 drivers/usb/core/hub.c:2663 hub_port_connect drivers/usb/core/hub.c:5535 [inline] hub_port_connect_change drivers/usb/core/hub.c:5675 [inline] port_event drivers/usb/core/hub.c:5835 [inline] hub_event+0x2f85/0x5030 drivers/usb/core/hub.c:5917 process_one_work+0x9cc/0x1b70 kernel/workqueue.c:3238 process_scheduled_works kernel/workqueue.c:3319 [inline] worker_thread+0x6c8/0xf10 kernel/workqueue.c:3400 kthread+0x3c2/0x780 kernel/kthread.c:464 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:153 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Showing all locks held in the system: 6 locks held by kworker/0:0/9: #0: ffff8881066b3d48 ( (wq_completion)usb_hub_wq ){+.+.}-{0:0} , at: process_one_work+0x12a2/0x1b70 kernel/workqueue.c:3213 #1: ffffc9000009fd18 ( (work_completion)(&hub->events) ){+.+.}-{0:0} , at: process_one_work+0x929/0x1b70 kernel/workqueue.c:3214 #2: ffff88810b78b198 ( &dev->mutex ){....}-{4:4} , at: device_lock include/linux/device.h:922 [inline] , at: hub_event+0x1be/0x5030 drivers/usb/core/hub.c:5863 #3: ffff888118a0d198 ( &dev->mutex ){....}-{4:4} , at: device_lock include/linux/device.h:922 [inline] , at: __device_attach+0x7e/0x4b0 drivers/base/dd.c:1005 #4: ffff88811266a160 ( &dev->mutex ){....}-{4:4} , at: device_lock include/linux/device.h:922 [inline] , at: __device_attach+0x7e/0x4b0 drivers/base/dd.c:1005 #5: ffffffff8a6720a8 ( uevent_sock_mutex ){+.+.}-{4:4} , at: uevent_net_broadcast_untagged lib/kobject_uevent.c:317 [inline] , at: kobject_uevent_net_broadcast lib/kobject_uevent.c:410 [inline] , at: kobject_uevent_env+0xb36/0x1870 lib/kobject_uevent.c:608 6 locks held by kworker/0:1/10: 1 lock held by khungtaskd/30: #0: ffffffff890c1a00 ( rcu_read_lock ){....}-{1:3} , at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] , at: rcu_read_lock include/linux/rcupdate.h:841 [inline] , at: debug_show_all_locks+0x36/0x1c0 kernel/locking/lockdep.c:6764 4 locks held by udevd/2839: #0: ffff8881153b83f8 ( sb_writers #8 ){.+.+}-{0:0} , at: ksys_write+0x12a/0x240 fs/read_write.c:736 #1: ffff888113296c88 ( &of->mutex ){+.+.}-{4:4} , at: kernfs_fop_write_iter+0x287/0x510 fs/kernfs/file.c:325 #2: ffff88810f2b42d8 ( kn->active #5 ){++++}-{0:0} , at: kernfs_fop_write_iter+0x2aa/0x510 fs/kernfs/file.c:326 #3: ffffffff8a6720a8 ( uevent_sock_mutex ){+.+.}-{4:4} , at: uevent_net_broadcast_untagged lib/kobject_uevent.c:317 [inline] , at: kobject_uevent_net_broadcast lib/kobject_uevent.c:410 [inline] , at: kobject_uevent_env+0xb36/0x1870 lib/kobject_uevent.c:608 2 locks held by getty/2897: #0: ffff8881152d00a0 ( &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/2940: #0: ffffffff890ccf38 ( rcu_state.exp_mutex ){+.+.}-{4:4} , at: exp_funnel_lock+0x280/0x3c0 kernel/rcu/tree_exp.h:304 1 lock held by syz-executor/2945: 5 locks held by kworker/1:3/5225: 4 locks held by udevd/5229: 8 locks held by kworker/1:5/5310: 5 locks held by kworker/0:5/5317: #0: ffff8881066b3d48 ( (wq_completion)usb_hub_wq ){+.+.}-{0:0} , at: process_one_work+0x12a2/0x1b70 kernel/workqueue.c:3213 #1: ffffc90002307d18 ( (work_completion)(&hub->events) ){+.+.}-{0:0} , at: process_one_work+0x929/0x1b70 kernel/workqueue.c:3214 #2: ffff88810afac198 ( &dev->mutex ){....}-{4:4} , at: device_lock include/linux/device.h:922 [inline] , at: hub_event+0x1be/0x5030 drivers/usb/core/hub.c:5863 #3: ffff88810afaf508 ( &port_dev->status_lock ){+.+.}-{4:4} , at: usb_lock_port drivers/usb/core/hub.c:3220 [inline] , at: hub_port_connect drivers/usb/core/hub.c:5432 [inline] , at: hub_port_connect_change drivers/usb/core/hub.c:5675 [inline] , at: port_event drivers/usb/core/hub.c:5835 [inline] , at: hub_event+0x29da/0x5030 drivers/usb/core/hub.c:5917 #4: ffff88810feb6e68 ( hcd->address0_mutex ){+.+.}-{4:4} , at: hub_port_connect drivers/usb/core/hub.c:5433 [inline] , at: hub_port_connect_change drivers/usb/core/hub.c:5675 [inline] , at: port_event drivers/usb/core/hub.c:5835 [inline] , at: hub_event+0x2a00/0x5030 drivers/usb/core/hub.c:5917 4 locks held by udevd/5383: #0: ffff888101f809e0 ( &p->lock ){+.+.}-{4:4} , at: seq_read_iter+0xe1/0x12b0 fs/seq_file.c:182 #1: ffff88810b3de488 ( &of->mutex #2 ){+.+.}-{4:4} , at: kernfs_seq_start+0x4d/0x240 fs/kernfs/file.c:154 #2: ffff88811d501008 ( kn->active #5 ){++++}-{0:0} , at: kernfs_seq_start+0x71/0x240 fs/kernfs/file.c:155 #3: ffff888118a0d198 ( &dev->mutex ){....}-{4:4} , at: device_lock include/linux/device.h:922 [inline] , at: uevent_show+0x187/0x3b0 drivers/base/core.c:2730 1 lock held by syz.4.727/7494: #0: ffffffff8a6720a8 ( uevent_sock_mutex ){+.+.}-{4:4} , at: uevent_net_broadcast_untagged lib/kobject_uevent.c:317 [inline] , at: kobject_uevent_net_broadcast lib/kobject_uevent.c:410 [inline] , at: kobject_uevent_env+0xb36/0x1870 lib/kobject_uevent.c:608 2 locks held by syz.3.728/7485: #0: ffff88810b320d78 ( &dev->mutex ){....}-{4:4} , at: device_lock include/linux/device.h:922 [inline] , at: __device_driver_lock drivers/base/dd.c:1095 [inline] , at: device_release_driver_internal+0xa4/0x620 drivers/base/dd.c:1293 #1: ffffffff8a6720a8 ( uevent_sock_mutex ){+.+.}-{4:4} , at: uevent_net_broadcast_untagged lib/kobject_uevent.c:317 [inline] , at: kobject_uevent_net_broadcast lib/kobject_uevent.c:410 [inline] , at: kobject_uevent_env+0xb36/0x1870 lib/kobject_uevent.c:608 2 locks held by syz.0.729/7489: #0: ffff888107b6cd78 ( &dev->mutex ){....}-{4:4} , at: device_lock include/linux/device.h:922 [inline] , at: __device_driver_lock drivers/base/dd.c:1095 [inline] , at: __driver_attach+0x278/0x580 drivers/base/dd.c:1215 #1: ffffffff8a6720a8 ( uevent_sock_mutex ){+.+.}-{4:4} , at: uevent_net_broadcast_untagged lib/kobject_uevent.c:317 [inline] , at: kobject_uevent_net_broadcast lib/kobject_uevent.c:410 [inline] , at: kobject_uevent_env+0xb36/0x1870 lib/kobject_uevent.c:608 1 lock held by syz.1.730/7491: #0: ffffffff890ccf38 ( rcu_state.exp_mutex ){+.+.}-{4:4} , at: exp_funnel_lock+0x1a3/0x3c0 kernel/rcu/tree_exp.h:336 2 locks held by syz.2.731/7493: ============================================= NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 30 Comm: khungtaskd Not tainted 6.15.0-rc1-syzkaller-00068-g169263214645 #0 PREEMPT(voluntary) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025 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:158 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:274 [inline] watchdog+0x11c4/0x15d0 kernel/hung_task.c:437 kthread+0x3c2/0x780 kernel/kthread.c:464 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:153 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Sending NMI from CPU 0 to CPUs 1: yealink 3-1:36.0: unexpected response 0 yealink 3-1:36.0: urb_ctl_callback - urb status -71 NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 5310 Comm: kworker/1:5 Not tainted 6.15.0-rc1-syzkaller-00068-g169263214645 #0 PREEMPT(voluntary) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025 Workqueue: events_power_efficient gc_worker RIP: 0010:io_serial_out+0x8f/0xb0 drivers/tty/serial/8250/8250_port.c:416 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 81 9e 09 ff eb a0 e8 0a 9f 09 RSP: 0000:ffffc900001a8500 EFLAGS: 00000002 RAX: 0000000000000035 RBX: 00000000000003f8 RCX: 0000000000000000 RDX: 00000000000003f8 RSI: ffffffff82ce5ab5 RDI: ffffffff938b6820 RBP: ffffffff938b67e0 R08: 0000000000000001 R09: 000000000000001f R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000 R13: 0000000000000035 R14: ffffffff938b67e0 R15: ffffffff82ce5a50 FS: 0000000000000000(0000) GS:ffff8882692d3000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007ffbb924e3a6 CR3: 0000000008ea4000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: serial_port_out include/linux/serial_core.h:796 [inline] serial8250_console_putchar drivers/tty/serial/8250/8250_port.c:3306 [inline] serial8250_console_fifo_write drivers/tty/serial/8250/8250_port.c:3378 [inline] serial8250_console_write+0xfbc/0x1890 drivers/tty/serial/8250/8250_port.c:3456 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 dev_vprintk_emit drivers/base/core.c:4891 [inline] dev_printk_emit+0xfa/0x140 drivers/base/core.c:4902 __dev_printk+0xf5/0x270 drivers/base/core.c:4914 _dev_err+0xe4/0x120 drivers/base/core.c:4957 urb_ctl_callback+0x1eb/0x2f0 drivers/input/misc/yealink.c:456 __usb_hcd_giveback_urb+0x38a/0x6e0 drivers/usb/core/hcd.c:1650 usb_hcd_giveback_urb+0x39b/0x450 drivers/usb/core/hcd.c:1734 dummy_timer+0x180e/0x3a20 drivers/usb/gadget/udc/dummy_hcd.c:1994 __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+0x205/0x8d0 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:1049 [inline] sysvec_apic_timer_interrupt+0x90/0xb0 arch/x86/kernel/apic/apic.c:1049 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:get_current arch/x86/include/asm/current.h:25 [inline] RIP: 0010:__sanitizer_cov_trace_pc+0x8/0x70 kernel/kcov.c:216 Code: e9 3d fe 53 00 be 03 00 00 00 5b e9 12 ac 03 01 66 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 48 8b 34 24 <65> 48 8b 15 a8 86 e8 0a 65 8b 05 b9 86 e8 0a a9 00 01 ff 00 74 1d RSP: 0000:ffffc90001ebfb58 EFLAGS: 00000202 RAX: 0000000000000000 RBX: 0000000000000001 RCX: ffffffff8638831e RDX: ffff888115cc57c0 RSI: ffffffff863889c8 RDI: 0000000000000005 RBP: ffffffff93a1de6c R08: 0000000000000005 R09: 0000000000000000 R10: 0000000000000001 R11: 0000000000000000 R12: ffff888112200000 R13: 0000000000008793 R14: dffffc0000000000 R15: 0000000000001770 rcu_read_unlock include/linux/rcupdate.h:869 [inline] gc_worker+0x1028/0x16d0 net/netfilter/nf_conntrack_core.c:1603 process_one_work+0x9cc/0x1b70 kernel/workqueue.c:3238 process_scheduled_works kernel/workqueue.c:3319 [inline] worker_thread+0x6c8/0xf10 kernel/workqueue.c:3400 kthread+0x3c2/0x780 kernel/kthread.c:464 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:153 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245