INFO: task udevd:2843 blocked for more than 143 seconds. Not tainted 6.16.0-rc7-syzkaller-g51d4b0a44c82 #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:udevd state:D stack:24520 pid:2843 tgid:2843 ppid:1 task_flags:0x400140 flags:0x00004002 Call Trace: context_switch kernel/sched/core.c:5397 [inline] __schedule+0x1325/0x3b10 kernel/sched/core.c:6786 __schedule_loop kernel/sched/core.c:6864 [inline] schedule+0xe7/0x3a0 kernel/sched/core.c:6879 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6936 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:1180 d_revalidate fs/namei.c:929 [inline] d_revalidate fs/namei.c:925 [inline] lookup_fast+0x266/0x610 fs/namei.c:1778 walk_component+0x5b/0x5b0 fs/namei.c:2134 link_path_walk+0x627/0xe20 fs/namei.c:2506 path_lookupat+0x15a/0x6d0 fs/namei.c:2662 filename_lookup+0x224/0x5f0 fs/namei.c:2692 do_readlinkat+0xce/0x3a0 fs/stat.c:576 __do_sys_readlink fs/stat.c:613 [inline] __se_sys_readlink fs/stat.c:610 [inline] __x64_sys_readlink+0x78/0xc0 fs/stat.c:610 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: 0033:0x7f0e0d3ca3a7 RSP: 002b:00007ffc844ac4b8 EFLAGS: 00000246 ORIG_RAX: 0000000000000059 RAX: ffffffffffffffda RBX: 00007ffc844ac990 RCX: 00007f0e0d3ca3a7 RDX: 0000000000000400 RSI: 00007ffc844ac4c0 RDI: 00007ffc844ac990 RBP: 00007ffc844ac4c0 R08: 0000000000000075 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000400 R13: 0000563143c22100 R14: 0000000000000001 R15: 00007ffc844ae290 Showing all locks held in the system: 1 lock held by khungtaskd/30: #0: ffffffff890c8440 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff890c8440 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline] #0: ffffffff890c8440 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x36/0x1c0 kernel/locking/lockdep.c:6770 4 locks held by kworker/1:1/38: #0: ffff888100080d48 ( (wq_completion)events ){+.+.}-{0:0} , at: process_one_work+0x12a2/0x1b70 kernel/workqueue.c:3213 #1: ffffc90000287d10 ( kernfs_notify_work ){+.+.}-{0:0} , at: process_one_work+0x929/0x1b70 kernel/workqueue.c:3214 #2: ffff888100ac4ab8 ( &root->kernfs_supers_rwsem ){++++}-{4:4} , at: kernfs_notify_workfn+0xf7/0xb30 fs/kernfs/file.c:914 #3: ffff888100ac4988 ( &root->kernfs_rwsem ){++++}-{4:4} , at: kernfs_notify_workfn+0xff/0xb30 fs/kernfs/file.c:915 7 locks held by kworker/0:2/2560: 1 lock held by udevd/2843: #0: ffff888100ac4988 (&root->kernfs_rwsem ){++++}-{4:4} , at: kernfs_dop_revalidate+0xa5/0x740 fs/kernfs/dir.c:1180 2 locks held by getty/2905: #0: ffff888107f8f0a0 ( &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 5 locks held by kworker/0:3/5232: 4 locks held by udevd/5492: #0: ffff8881357e2d58 ( &p->lock){+.+.}-{4:4} , at: seq_read_iter+0xe1/0x12c0 fs/seq_file.c:182 #1: ffff888116dba488 (&of->mutex#2){+.+.}-{4:4} , at: kernfs_seq_start+0x4d/0x240 fs/kernfs/file.c:154 #2: ffff888133eeb5a8 ( kn->active#23 ){++++}-{0:0} , at: kernfs_seq_start+0x71/0x240 fs/kernfs/file.c:155 #3: ffff888113e9d198 ( &dev->mutex){....}-{4:4} , at: device_lock_interruptible include/linux/device.h:889 [inline] , at: manufacturer_show+0x26/0xa0 drivers/usb/core/sysfs.c:142 6 locks held by kworker/1:6/5591: #0: ffff8881066f3948 ( (wq_completion)usb_hub_wq ){+.+.}-{0:0} , at: process_one_work+0x12a2/0x1b70 kernel/workqueue.c:3213 #1: ffffc900033ffd10 ( (work_completion)(&hub->events) ){+.+.}-{0:0} , at: process_one_work+0x929/0x1b70 kernel/workqueue.c:3214 #2: ffff88810b35b198 (&dev->mutex ){....}-{4:4} , at: device_lock include/linux/device.h:884 [inline] , at: hub_event+0x1be/0x5060 drivers/usb/core/hub.c:5898 #3: ffff88811f805198 ( &dev->mutex ){....}-{4:4} , at: device_lock include/linux/device.h:884 [inline] , at: usb_disconnect+0x10a/0x9c0 drivers/usb/core/hub.c:2335 #4: ffff888106ecc278 (&(&priv->bus_notifier)->rwsem ){++++}-{4:4} , at: blocking_notifier_call_chain kernel/notifier.c:379 [inline] , at: blocking_notifier_call_chain+0x53/0xa0 kernel/notifier.c:368 #5: ffff888100ac4988 (&root->kernfs_rwsem ){++++}-{4:4} , at: kernfs_remove_by_name_ns+0x3d/0x110 fs/kernfs/dir.c:1712 4 locks held by kworker/u8:0/8265: 1 lock held by syz.0.1630/11011: #0: ffff888100ac4988 (&root->kernfs_rwsem ){++++}-{4:4} , at: kernfs_add_one+0x38/0x840 fs/kernfs/dir.c:791 1 lock held by syz-executor/11020: #0: ffff888100ac4988 ( &root->kernfs_rwsem){++++}-{4:4} , at: kernfs_dop_revalidate+0xa5/0x740 fs/kernfs/dir.c:1180 1 lock held by syz-executor/11022: #0: ffff888100ac4988 (&root->kernfs_rwsem ){++++}-{4:4} , at: kernfs_dop_revalidate+0xa5/0x740 fs/kernfs/dir.c:1180 1 lock held by syz-executor/11023: #0: ffff888100ac4988 ( &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 6.16.0-rc7-syzkaller-g51d4b0a44c82 #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:158 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:307 [inline] watchdog+0xf70/0x12c0 kernel/hung_task.c:470 kthread+0x3c2/0x780 kernel/kthread.c:464 ret_from_fork+0x5b3/0x6c0 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: yealink 5-1:36.0: urb_irq_callback - urb status -71 NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 2560 Comm: kworker/0:2 Not tainted 6.16.0-rc7-syzkaller-g51d4b0a44c82 #0 PREEMPT(voluntary) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025 Workqueue: events_power_efficient gc_worker 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 2d 1e 55 00 be 03 00 00 00 5b e9 d2 19 09 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 68 69 ee 0a 65 8b 05 79 69 ee 0a a9 00 01 ff 00 74 1d RSP: 0018:ffffc90000007490 EFLAGS: 00000046 RAX: 000000000000004b RBX: 1ffff92000000e98 RCX: 1ffff92000000eda RDX: 0000000000000000 RSI: ffffffff815d3c9a RDI: ffffc900000076d0 RBP: ffffc900000076c8 R08: 0000000000000007 R09: 0000000000000000 R10: 0000000000000800 R11: 205d304320202020 R12: 0000000000000000 R13: 0000000000000001 R14: ffffc900000074e0 R15: ffffc90000007520 FS: 0000000000000000(0000) GS:ffff888269160000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000200000001380 CR3: 00000001342b6000 CR4: 00000000003506f0 Call Trace: printk_get_next_message+0x30a/0x6d0 kernel/printk/printk.c:3028 console_emit_next_record kernel/printk/printk.c:3092 [inline] console_flush_all+0x6ea/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:4917 [inline] dev_printk_emit+0xfa/0x140 drivers/base/core.c:4928 __dev_printk+0xf5/0x270 drivers/base/core.c:4940 _dev_err+0xe4/0x120 drivers/base/core.c:4983 urb_irq_callback+0x454/0x700 drivers/input/misc/yealink.c:418 __usb_hcd_giveback_urb+0x38d/0x6e0 drivers/usb/core/hcd.c:1663 usb_hcd_giveback_urb+0x39b/0x450 drivers/usb/core/hcd.c:1747 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:lock_is_held_type+0x107/0x150 kernel/locking/lockdep.c:5948 Code: 00 00 b8 ff ff ff ff 65 0f c1 05 6c dd 3c 05 83 f8 01 75 2d 9c 58 f6 c4 02 75 43 48 f7 04 24 00 02 00 00 74 01 fb 48 83 c4 08 <44> 89 e8 5b 5d 41 5c 41 5d 41 5e 41 5f e9 97 9d 02 00 45 31 ed eb RSP: 0018:ffffc900036afa98 EFLAGS: 00000282 RAX: 0000000000000046 RBX: ffff888114840ad0 RCX: 0000000000000001 RDX: 0000000000000000 RSI: ffffffff88ae59a0 RDI: ffffffff87690bc0 RBP: ffffffff890c83e0 R08: 0000000000000001 R09: 0000000000000000 R10: 0000000000000001 R11: 0000000000000001 R12: ffff888114840000 R13: 0000000000000000 R14: 00000000ffffffff R15: 0000000000000002 lock_is_held include/linux/lockdep.h:249 [inline] __might_resched+0x473/0x5e0 kernel/sched/core.c:8762 gc_worker+0x9b6/0x16d0 net/netfilter/nf_conntrack_core.c:1621 process_one_work+0x9cc/0x1b70 kernel/workqueue.c:3238 process_scheduled_works kernel/workqueue.c:3321 [inline] worker_thread+0x6c8/0xf10 kernel/workqueue.c:3402 kthread+0x3c2/0x780 kernel/kthread.c:464 ret_from_fork+0x5b3/0x6c0 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245