INFO: task udevd:4795 blocked for more than 143 seconds. Not tainted 6.10.0-rc4-syzkaller-00053-g819984a0dd36 #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:udevd state:D stack:24880 pid:4795 tgid:4795 ppid:2403 flags:0x00004002 Call Trace: context_switch kernel/sched/core.c:5408 [inline] __schedule+0xca6/0x3170 kernel/sched/core.c:6745 __schedule_loop kernel/sched/core.c:6822 [inline] schedule+0xe7/0x350 kernel/sched/core.c:6837 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6894 __mutex_lock_common kernel/locking/mutex.c:684 [inline] __mutex_lock+0x5b8/0x9c0 kernel/locking/mutex.c:752 device_lock include/linux/device.h:1009 [inline] uevent_show+0x188/0x3b0 drivers/base/core.c:2743 dev_attr_show+0x53/0xe0 drivers/base/core.c:2437 sysfs_kf_seq_show+0x23e/0x410 fs/sysfs/file.c:59 seq_read_iter+0x4fa/0x12c0 fs/seq_file.c:230 kernfs_fop_read_iter+0x41a/0x590 fs/kernfs/file.c:279 new_sync_read fs/read_write.c:395 [inline] vfs_read+0x869/0xbd0 fs/read_write.c:476 ksys_read+0x12f/0x260 fs/read_write.c:619 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xcd/0x250 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fe8dc1f0b6a RSP: 002b:00007ffc29298938 EFLAGS: 00000246 ORIG_RAX: 0000000000000000 RAX: ffffffffffffffda RBX: 000055d1f3149730 RCX: 00007fe8dc1f0b6a RDX: 0000000000001000 RSI: 000055d1f3136970 RDI: 0000000000000008 RBP: 000055d1f3149730 R08: 0000000000000008 R09: 0000000000000000 R10: 000000000000010f R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000003fff R14: 00007ffc29298e18 R15: 000000000000000a Showing all locks held in the system: 2 locks held by kworker/0:1/9: 1 lock held by khungtaskd/30: #0: ffffffff886b4660 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:329 [inline] #0: ffffffff886b4660 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:781 [inline] #0: ffffffff886b4660 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x75/0x340 kernel/locking/lockdep.c:6614 2 locks held by kworker/u8:5/167: #0: ffff888100089148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work+0x12bf/0x1b60 kernel/workqueue.c:3206 #1: ffffc90001607d80 ((work_completion)(&sub_info->work)){+.+.}-{0:0}, at: process_one_work+0x957/0x1b60 kernel/workqueue.c:3207 2 locks held by kworker/u8:6/999: #0: ffff888100089148 ( (wq_completion)events_unbound ){+.+.}-{0:0} , at: process_one_work+0x12bf/0x1b60 kernel/workqueue.c:3206 #1: ffffc900020ffd80 ( (work_completion)(&sub_info->work) ){+.+.}-{0:0} , at: process_one_work+0x957/0x1b60 kernel/workqueue.c:3207 2 locks held by getty/2463: #0: ffff888107e8d0a0 ( &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+0xfc8/0x1490 drivers/tty/n_tty.c:2211 1 lock held by syz-fuzzer/2517: 4 locks held by udevd/4795: #0: ffff88811876ab08 (&p->lock ){+.+.}-{3:3} , at: seq_read_iter+0xde/0x12c0 fs/seq_file.c:182 #1: ffff888122440488 ( &of->mutex #2 ){+.+.}-{3:3} , at: kernfs_seq_start+0x4d/0x240 fs/kernfs/file.c:154 #2: ffff88812f45f878 (kn->active #3 ){++++}-{0:0} , at: kernfs_seq_start+0x71/0x240 fs/kernfs/file.c:155 #3: ffff888119a6a190 ( &dev->mutex ){....}-{3:3} , at: device_lock include/linux/device.h:1009 [inline] , at: uevent_show+0x188/0x3b0 drivers/base/core.c:2743 7 locks held by kworker/0:4/4820: 6 locks held by kworker/0:7/9699: 1 lock held by syz-executor.3/20568: #0: ffffffff886bfdf8 ( rcu_state.exp_mutex ){+.+.}-{3:3} , at: exp_funnel_lock+0x1a4/0x3b0 kernel/rcu/tree_exp.h:323 1 lock held by syz-executor.1/20574: #0: ffffffff886bfdf8 (rcu_state.exp_mutex ){+.+.}-{3:3} , at: exp_funnel_lock+0x282/0x3b0 kernel/rcu/tree_exp.h:291 1 lock held by modprobe/22264: 1 lock held by modprobe/22265: ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 30 Comm: khungtaskd Not tainted 6.10.0-rc4-syzkaller-00053-g819984a0dd36 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/07/2024 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:114 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+0xf86/0x1240 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: yealink 3-1:36.0: urb_ctl_callback - urb status -71 NMI backtrace for cpu 0 CPU: 0 PID: 4820 Comm: kworker/0:4 Not tainted 6.10.0-rc4-syzkaller-00053-g819984a0dd36 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/07/2024 Workqueue: events drain_vmap_area_work RIP: 0010:io_serial_in+0x87/0xb0 drivers/tty/serial/8250/8250_port.c:407 Code: 34 b9 fe 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 1a 66 03 5d 40 89 da ec <5b> 0f b6 c0 5d 41 5c c3 cc cc cc cc e8 18 90 0b ff eb a2 e8 a1 90 RSP: 0018:ffffc900000075c8 EFLAGS: 00000006 RAX: dffffc0000000005 RBX: 00000000000003f9 RCX: 0000000000000000 RDX: 00000000000003f9 RSI: ffffffff829a0f40 RDI: ffffffff8d719be0 RBP: ffffffff8d719ba0 R08: 0000000000000001 R09: 000000000000001f R10: 0000000000000000 R11: 0000000000000006 R12: 0000000000000000 R13: ffffffff8d719ba0 R14: ffffffff8d719bf0 R15: 000000000000004b FS: 0000000000000000(0000) GS:ffff8881f6400000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000020848000 CR3: 0000000116c1e000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: serial_port_in include/linux/serial_core.h:674 [inline] serial8250_console_write+0x17d/0x1090 drivers/tty/serial/8250/8250_port.c:3357 console_emit_next_record kernel/printk/printk.c:2928 [inline] console_flush_all+0x53c/0xd70 kernel/printk/printk.c:2994 console_unlock+0xae/0x290 kernel/printk/printk.c:3063 vprintk_emit kernel/printk/printk.c:2345 [inline] vprintk_emit+0x11a/0x5a0 kernel/printk/printk.c:2300 dev_vprintk_emit drivers/base/core.c:4909 [inline] dev_printk_emit+0xfb/0x140 drivers/base/core.c:4920 __dev_printk+0xf5/0x270 drivers/base/core.c:4932 _dev_err+0xe5/0x120 drivers/base/core.c:4975 urb_ctl_callback+0x1eb/0x2f0 drivers/input/misc/yealink.c:454 __usb_hcd_giveback_urb+0x466/0x6e0 drivers/usb/core/hcd.c:1650 usb_hcd_giveback_urb+0x396/0x450 drivers/usb/core/hcd.c:1734 dummy_timer+0x17f6/0x3900 drivers/usb/gadget/udc/dummy_hcd.c:1987 __run_hrtimer kernel/time/hrtimer.c:1687 [inline] __hrtimer_run_queues+0x20c/0xcc0 kernel/time/hrtimer.c:1751 hrtimer_interrupt+0x31b/0x800 kernel/time/hrtimer.c:1813 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1032 [inline] __sysvec_apic_timer_interrupt+0x10f/0x450 arch/x86/kernel/apic/apic.c:1049 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1043 [inline] sysvec_apic_timer_interrupt+0x8b/0xb0 arch/x86/kernel/apic/apic.c:1043 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:preempt_count arch/x86/include/asm/preempt.h:26 [inline] RIP: 0010:check_kcov_mode kernel/kcov.c:173 [inline] RIP: 0010:write_comp_data+0x11/0x90 kernel/kcov.c:236 Code: cc cc 0f 1f 80 00 00 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 49 89 d2 49 89 f8 49 89 f1 65 48 8b 15 bf 88 b0 7e <65> 8b 05 c0 88 b0 7e a9 00 01 ff 00 74 0f f6 c4 01 74 59 8b 82 54 RSP: 0018:ffffc900043979c8 EFLAGS: 00000202 RAX: 0000000000000001 RBX: ffff8881f6543000 RCX: ffffffff8147397b RDX: ffff8881194e8000 RSI: 0000000000000000 RDI: 0000000000000005 RBP: 0000000000000003 R08: 0000000000000005 R09: 0000000000000000 R10: 0000000000000001 R11: 0000000000000000 R12: ffffed103eca8601 R13: 0000000000000001 R14: ffff8881f6543008 R15: ffff8881f643e900 csd_lock_wait kernel/smp.c:311 [inline] smp_call_function_many_cond+0x50b/0x1420 kernel/smp.c:855 on_each_cpu_cond_mask+0x40/0x90 kernel/smp.c:1023 on_each_cpu include/linux/smp.h:71 [inline] flush_tlb_kernel_range+0x82/0xb0 arch/x86/mm/tlb.c:1076 purge_vmap_node+0x3fc/0x920 mm/vmalloc.c:2207 __purge_vmap_area_lazy+0x9ca/0xc10 mm/vmalloc.c:2289 drain_vmap_area_work+0x27/0x40 mm/vmalloc.c:2323 process_one_work+0x9fb/0x1b60 kernel/workqueue.c:3231 process_scheduled_works kernel/workqueue.c:3312 [inline] worker_thread+0x6c8/0xf70 kernel/workqueue.c:3393 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