INFO: task udevd:2853 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:udevd state:D stack:23656 pid:2853 tgid:2853 ppid:1 task_flags:0x400140 flags:0x00080001 Call Trace: context_switch kernel/sched/core.c:5325 [inline] __schedule+0x12fc/0x3b80 kernel/sched/core.c:6929 __schedule_loop kernel/sched/core.c:7011 [inline] schedule+0xe7/0x3a0 kernel/sched/core.c:7026 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7083 rwsem_down_read_slowpath+0x64b/0xbf0 kernel/locking/rwsem.c:1086 __down_read_common kernel/locking/rwsem.c:1261 [inline] __down_read kernel/locking/rwsem.c:1274 [inline] down_read+0xef/0x480 kernel/locking/rwsem.c:1539 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:1777 walk_component+0x5b/0x5b0 fs/namei.c:2147 link_path_walk+0x627/0xe20 fs/namei.c:2519 path_lookupat+0x15a/0x6d0 fs/namei.c:2675 filename_lookup+0x224/0x5f0 fs/namei.c:2705 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/0x4d0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fb5adf8a3a7 RSP: 002b:00007fff2b2374b8 EFLAGS: 00000246 ORIG_RAX: 0000000000000059 RAX: ffffffffffffffda RBX: 00007fff2b237990 RCX: 00007fb5adf8a3a7 RDX: 0000000000000400 RSI: 00007fff2b2374c0 RDI: 00007fff2b237990 RBP: 00007fff2b2374c0 R08: 0000000000000075 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000400 R13: 0000560523bd0100 R14: 0000000000000001 R15: 00007fff2b239290 Showing all locks held in the system: 5 locks held by kworker/0:1/10: 1 lock held by khungtaskd/30: #0: ffffffff892c89e0 (rcu_read_lock ){....}-{1:3} , at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] , at: rcu_read_lock include/linux/rcupdate.h:867 [inline] , at: debug_show_all_locks+0x36/0x1c0 kernel/locking/lockdep.c:6775 3 locks held by kworker/1:1/42: 2 locks held by kworker/u8:7/350: 2 locks held by getty/2915: #0: ffff88811280f0a0 ( &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/2960: 1 lock held by syz-executor/2963: 1 lock held by syz-executor/2964: #0: ffffffff892d3f78 ( rcu_state.exp_mutex ){+.+.}-{4:4}, at: exp_funnel_lock+0x1a3/0x3c0 kernel/rcu/tree_exp.h:343 1 lock held by syz-executor/2966: 1 lock held by syz-executor/2967: 5 locks held by kworker/0:4/5227: 8 locks held by kworker/0:5/5256: 4 locks held by udevd/5347: #0: ffff888116fd1c30 ( &p->lock ){+.+.}-{4:4} , at: seq_read_iter+0xe1/0x12d0 fs/seq_file.c:182 #1: ffff88810ab61c88 ( &of->mutex #2 ){+.+.}-{4:4} , at: kernfs_seq_start+0x4f/0x2a0 fs/kernfs/file.c:172 #2: ffff888113c50008 ( kn->active#9 ){++++}-{0:0} , at: kernfs_get_active_of fs/kernfs/file.c:80 [inline] , at: kernfs_seq_start+0xbc/0x2a0 fs/kernfs/file.c:173 #3: ffff888114674198 ( &dev->mutex){....}-{4:4} , at: device_lock_interruptible include/linux/device.h:919 [inline] , at: manufacturer_show+0x26/0xa0 drivers/usb/core/sysfs.c:142 6 locks held by kworker/0:6/5640: 3 locks held by kworker/1:7/7643: ============================================= 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 10/02/2025 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:332 [inline] watchdog+0xf3f/0x1170 kernel/hung_task.c:495 kthread+0x3c5/0x780 kernel/kthread.c:463 ret_from_fork+0x56d/0x700 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Sending NMI from CPU 1 to CPUs 0: yealink 1-1:36.0: urb_ctl_callback - urb status -71 NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 5256 Comm: kworker/0:5 Not tainted syzkaller #0 PREEMPT(voluntary) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025 Workqueue: events_power_efficient gc_worker RIP: 0010:memcpy_orig+0x58/0x130 arch/x86/lib/memcpy_64.S:96 Code: 4f 08 4c 89 57 10 4c 89 5f 18 48 8d 7f 20 73 d4 83 c2 20 eb 44 48 01 d6 48 01 d7 48 83 ea 20 0f 1f 00 48 83 ea 20 4c 8b 46 f8 <4c> 8b 4e f0 4c 8b 56 e8 4c 8b 5e e0 48 8d 76 e0 4c 89 47 f8 4c 89 RSP: 0018:ffffc900000072c8 EFLAGS: 00000087 RAX: ffffffff93a1f420 RBX: 0000000000000800 RCX: ffffffff815e5d1e RDX: ffffffffffffffe7 RSI: ffffffff93a50fb7 RDI: ffffffff93a1f447 RBP: 0000000000000027 R08: 302065736e6f7073 R09: fffffbfff2743e88 R10: ffffffff93a1f446 R11: 8000000062000027 R12: ffffffff93a1f420 R13: 000000000000d65e R14: ffffffff891d5ce0 R15: ffffc900000073a0 FS: 0000000000000000(0000) GS:ffff888268ea0000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007feabfa91000 CR3: 00000000090a4000 CR4: 00000000003506f0 Call Trace: copy_data kernel/printk/printk_ringbuffer.c:1869 [inline] prb_read kernel/printk/printk_ringbuffer.c:1954 [inline] _prb_read_valid+0x48e/0x890 kernel/printk/printk_ringbuffer.c:2131 prb_read_valid+0x78/0xa0 kernel/printk/printk_ringbuffer.c:2203 printk_get_next_message+0x15b/0x6d0 kernel/printk/printk.c:2978 console_emit_next_record kernel/printk/printk.c:3065 [inline] console_flush_all+0x6ea/0xc60 kernel/printk/printk.c:3199 __console_flush_and_unlock kernel/printk/printk.c:3258 [inline] console_unlock+0xd8/0x210 kernel/printk/printk.c:3298 vprintk_emit+0x3d7/0x680 kernel/printk/printk.c:2423 dev_vprintk_emit drivers/base/core.c:4914 [inline] dev_printk_emit+0xfa/0x140 drivers/base/core.c:4925 __dev_printk+0xf5/0x270 drivers/base/core.c:4937 _dev_err+0xe4/0x120 drivers/base/core.c:4980 urb_ctl_callback+0x1eb/0x2f0 drivers/input/misc/yealink.c:456 __usb_hcd_giveback_urb+0x38b/0x610 drivers/usb/core/hcd.c:1661 usb_hcd_giveback_urb+0x39b/0x450 drivers/usb/core/hcd.c:1745 dummy_timer+0x1809/0x3a00 drivers/usb/gadget/udc/dummy_hcd.c:1995 __run_hrtimer kernel/time/hrtimer.c:1777 [inline] __hrtimer_run_queues+0x202/0xad0 kernel/time/hrtimer.c:1841 hrtimer_run_softirq+0x17d/0x350 kernel/time/hrtimer.c:1858 handle_softirqs+0x208/0x8d0 kernel/softirq.c:622 __do_softirq kernel/softirq.c:656 [inline] invoke_softirq kernel/softirq.c:496 [inline] __irq_exit_rcu+0xfa/0x160 kernel/softirq.c:723 irq_exit_rcu+0x9/0x30 kernel/softirq.c:739 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1052 [inline] sysvec_apic_timer_interrupt+0x90/0xb0 arch/x86/kernel/apic/apic.c:1052 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697 RIP: 0010:__seqprop_spinlock_sequence include/linux/seqlock.h:227 [inline] RIP: 0010:nf_conntrack_get_ht include/net/netfilter/nf_conntrack.h:342 [inline] RIP: 0010:gc_worker+0x2d5/0x16d0 net/netfilter/nf_conntrack_core.c:1548 Code: 00 00 48 c7 c7 28 2d a1 8a e8 47 9b 04 fb 9c 5b 81 e3 00 02 00 00 31 ff 48 89 de e8 75 3e 28 fb 58 48 85 db 0f 85 d0 0f 00 00 f6 42 28 fb 8b 1d b0 21 4b 04 41 89 dc 31 ff 41 83 e4 01 44 89 RSP: 0018:ffffc90004727b58 EFLAGS: 00000293 RAX: 0000000000000000 RBX: 0000000000000000 RCX: ffffffff865616a9 RDX: ffff8881157c8000 RSI: ffffffff865616b8 RDI: 0000000000000007 RBP: ffffffff93d44dcc R08: 0000000000000007 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000001 R12: ffff888112400000 R13: 0000000000040000 R14: dffffc0000000000 R15: 0000000000001770 process_one_work+0x9cf/0x1b70 kernel/workqueue.c:3263 process_scheduled_works kernel/workqueue.c:3346 [inline] worker_thread+0x6c8/0xf10 kernel/workqueue.c:3427 kthread+0x3c5/0x780 kernel/kthread.c:463 ret_from_fork+0x56d/0x700 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245