INFO: task kworker/1:2:1116 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kworker/1:2 state:D stack:21928 pid:1116 tgid:1116 ppid:2 task_flags:0x4208060 flags:0x00080000 Workqueue: usb_hub_wq hub_event Call Trace: context_switch kernel/sched/core.c:5298 [inline] __schedule+0xeb1/0x4220 kernel/sched/core.c:6911 __schedule_loop kernel/sched/core.c:6993 [inline] schedule+0xdd/0x390 kernel/sched/core.c:7008 schedule_timeout+0x127/0x280 kernel/time/sleep_timeout.c:99 do_wait_for_common kernel/sched/completion.c:100 [inline] __wait_for_common+0x2e7/0x4c0 kernel/sched/completion.c:121 usb_start_wait_urb+0x2ae/0x580 drivers/usb/core/message.c:72 usb_internal_control_msg drivers/usb/core/message.c:117 [inline] usb_control_msg+0x328/0x4b0 drivers/usb/core/message.c:167 get_port_status drivers/usb/core/hub.c:607 [inline] hub_ext_port_status+0x152/0x600 drivers/usb/core/hub.c:624 usb_hub_port_status drivers/usb/core/hub.c:674 [inline] port_event drivers/usb/core/hub.c:5761 [inline] hub_event+0x6d2/0x4af0 drivers/usb/core/hub.c:5953 process_one_work+0xa23/0x19a0 kernel/workqueue.c:3276 process_scheduled_works kernel/workqueue.c:3359 [inline] worker_thread+0x5ef/0xe50 kernel/workqueue.c:3440 kthread+0x370/0x450 kernel/kthread.c:436 ret_from_fork+0x6c3/0xcb0 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 INFO: task syz.0.345:6383 blocked for more than 171 seconds. Not tainted syzkaller #0 Blocked by coredump. "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.0.345 state:D stack:27432 pid:6383 tgid:6382 ppid:2962 task_flags:0x40044c flags:0x00080003 Call Trace: context_switch kernel/sched/core.c:5298 [inline] __schedule+0xeb1/0x4220 kernel/sched/core.c:6911 __schedule_loop kernel/sched/core.c:6993 [inline] schedule+0xdd/0x390 kernel/sched/core.c:7008 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7065 rwsem_down_write_slowpath+0x530/0x1280 kernel/locking/rwsem.c:1185 __down_write_common kernel/locking/rwsem.c:1317 [inline] __down_write kernel/locking/rwsem.c:1326 [inline] down_write+0x1c7/0x1f0 kernel/locking/rwsem.c:1591 kernfs_remove_by_name_ns+0x3d/0xf0 fs/kernfs/dir.c:1717 sysfs_remove_file include/linux/sysfs.h:780 [inline] driver_remove_file drivers/base/driver.c:201 [inline] driver_remove_file+0x4a/0x60 drivers/base/driver.c:197 remove_bind_files drivers/base/bus.c:683 [inline] bus_remove_driver+0x248/0x2e0 drivers/base/bus.c:821 driver_unregister+0x76/0xb0 drivers/base/driver.c:277 usb_gadget_unregister_driver+0x49/0x70 drivers/usb/gadget/udc/core.c:1752 raw_release+0x19b/0x260 drivers/usb/gadget/legacy/raw_gadget.c:463 __fput+0x3ff/0xb40 fs/file_table.c:469 task_work_run+0x150/0x240 kernel/task_work.c:233 exit_task_work include/linux/task_work.h:40 [inline] do_exit+0x8b8/0x2b60 kernel/exit.c:976 do_group_exit+0xd5/0x2a0 kernel/exit.c:1118 get_signal+0x1ec7/0x21e0 kernel/signal.c:3034 arch_do_signal_or_restart+0x91/0x7a0 arch/x86/kernel/signal.c:337 __exit_to_user_mode_loop kernel/entry/common.c:64 [inline] exit_to_user_mode_loop+0x7e/0x430 kernel/entry/common.c:98 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:226 [inline] syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:256 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:325 [inline] do_syscall_64+0x671/0x7b0 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7ff3558ec4ab RSP: 002b:00007ff35433cf00 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: fffffffffffffffc RBX: 0000000000000003 RCX: 00007ff3558ec4ab RDX: 00007ff35433dfd0 RSI: 0000000080085502 RDI: 0000000000000003 RBP: 00007ff35433dfd0 R08: 0000000000000001 R09: 00000000ffffffff R10: 0000000000000000 R11: 0000000000000246 R12: 0000000080085502 R13: 0000000800000000 R14: 0000000000000000 R15: 00007ff3559a0ede Showing all locks held in the system: 3 locks held by kworker/0:0/9: 1 lock held by khungtaskd/30: #0: ffffffff896de760 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:312 [inline] ffffffff896de760 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:850 [inline] ffffffff896de760 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x3d/0x184 kernel/locking/lockdep.c:6775 5 locks held by kworker/1:2/1116: 4 locks held by kworker/0:2/2658: 1 lock held by udevd/2853: #0: ffff888101298188 ( &root->kernfs_rwsem ){++++}-{4:4} , at: kernfs_dop_revalidate+0xa5/0x740 fs/kernfs/dir.c:1185 2 locks held by getty/2915: #0: ffff8881124300a0 ( &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+0x419/0x1500 drivers/tty/n_tty.c:2211 1 lock held by syz-executor/2961: #0: ffff888101298188 (&root->kernfs_rwsem){++++}-{4:4} , at: kernfs_dop_revalidate+0x397/0x740 fs/kernfs/dir.c:1167 1 lock held by syz-executor/2962: #0: ffff888101298188 (&root->kernfs_rwsem ){++++}-{4:4}, at: kernfs_dop_revalidate+0x397/0x740 fs/kernfs/dir.c:1167 1 lock held by syz-executor/2963: #0: ffff888101298188 ( &root->kernfs_rwsem ){++++}-{4:4} , at: kernfs_dop_revalidate+0x397/0x740 fs/kernfs/dir.c:1167 1 lock held by syz-executor/2964: #0: ffff888101298188 ( &root->kernfs_rwsem ){++++}-{4:4} , at: kernfs_dop_revalidate+0x397/0x740 fs/kernfs/dir.c:1167 1 lock held by syz-executor/2969: #0: ffff888101298188 (&root->kernfs_rwsem ){++++}-{4:4}, at: kernfs_dop_revalidate+0x397/0x740 fs/kernfs/dir.c:1167 4 locks held by kworker/0:5/5221: #0: ffff8881062a4d48 ((wq_completion)usb_hub_wq){+.+.}-{0:0} , at: process_one_work+0x1310/0x19a0 kernel/workqueue.c:3251 #1: ffffc9000529fd18 ((work_completion)(&hub->events)){+.+.}-{0:0} , at: process_one_work+0x988/0x19a0 kernel/workqueue.c:3252 #2: ffff88810b71b1e0 ( &dev->mutex ){....}-{4:4} , at: device_lock include/linux/device.h:949 [inline] , at: hub_event+0x1bd/0x4af0 drivers/usb/core/hub.c:5899 #3: ffff888101298188 ( &root->kernfs_rwsem ){++++}-{4:4} , at: kernfs_activate fs/kernfs/dir.c:1430 [inline] , at: kernfs_add_one+0x54f/0x850 fs/kernfs/dir.c:839 2 locks held by kworker/0:6/5225: 4 locks held by kworker/1:3/5235: 5 locks held by kworker/1:6/5324: 5 locks held by kworker/1:7/5553: 1 lock held by syz.1.341/6369: 1 lock held by syz.3.344/6381: 1 lock held by syz.0.345/6383: #0: ffff888101298188 (&root->kernfs_rwsem){++++}-{4:4} , at: kernfs_remove_by_name_ns+0x3d/0xf0 fs/kernfs/dir.c:1717 1 lock held by syz-executor/6388: #0: ffff888101298188 ( &root->kernfs_rwsem){++++}-{4:4} , at: kernfs_dop_revalidate+0xa5/0x740 fs/kernfs/dir.c:1185 1 lock held by syz-executor/6389: #0: ffff888101298188 ( &root->kernfs_rwsem ){++++}-{4:4} , at: kernfs_dop_revalidate+0xa5/0x740 fs/kernfs/dir.c:1185 1 lock held by syz-executor/6390: #0: ffff888101298188 ( &root->kernfs_rwsem ){++++}-{4:4} , at: kernfs_dop_revalidate+0xa5/0x740 fs/kernfs/dir.c:1185 1 lock held by syz-executor/6391: #0: ffff888101298188 (&root->kernfs_rwsem){++++}-{4:4}, at: kernfs_dop_revalidate+0xa5/0x740 fs/kernfs/dir.c:1185 1 lock held by syz-executor/6392: #0: ffff888101298188 ( &root->kernfs_rwsem){++++}-{4:4}, at: kernfs_dop_revalidate+0xa5/0x740 fs/kernfs/dir.c:1185 ============================================= NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 30 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026 Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x100/0x190 lib/dump_stack.c:120 nmi_cpu_backtrace.cold+0x12d/0x151 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x1d7/0x230 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:161 [inline] __sys_info lib/sys_info.c:157 [inline] sys_info+0x141/0x190 lib/sys_info.c:165 check_hung_uninterruptible_tasks kernel/hung_task.c:346 [inline] watchdog+0xd25/0x1050 kernel/hung_task.c:515 kthread+0x370/0x450 kernel/kthread.c:436 ret_from_fork+0x6c3/0xcb0 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 4-1:36.0: urb_irq_callback - urb status -71 NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 2658 Comm: kworker/0:2 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026 Workqueue: events_power_efficient gc_worker RIP: 0010:__sanitizer_cov_trace_pc+0xb/0x70 kernel/kcov.c:213 Code: 5b 00 be 03 00 00 00 5b e9 c2 fd 1a 01 66 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 65 8b 05 e5 73 43 0b <48> 8b 34 24 65 48 8b 15 c1 73 43 0b a9 00 01 ff 00 74 1b f6 c4 01 RSP: 0018:ffffc90000006f20 EFLAGS: 00000087 RAX: 0000000080000102 RBX: ffffc9000000735b RCX: ffffffff87661071 RDX: ffff888115041d80 RSI: ffffffff87660ffd RDI: ffff888115041d80 RBP: 0000000000000000 R08: 0000000000000005 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000267148 R12: ffffc9000000735d R13: ffffc90080007357 R14: ffffc90000006fc8 R15: dffffc0000000000 FS: 0000000000000000(0000) GS:ffff8882686c9000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007ff35590b9b0 CR3: 00000000094ae000 CR4: 00000000003506f0 Call Trace: number+0x887/0xc90 lib/vsprintf.c:573 vsnprintf+0x30e/0x1240 lib/vsprintf.c:2912 sprintf+0xcc/0x100 lib/vsprintf.c:3111 print_time kernel/printk/printk.c:1359 [inline] info_print_prefix+0x25a/0x350 kernel/printk/printk.c:1385 record_print_text+0x143/0x3c0 kernel/printk/printk.c:1434 printk_get_next_message+0x2d1/0x6c0 kernel/printk/printk.c:3072 console_emit_next_record kernel/printk/printk.c:3137 [inline] console_flush_one_record+0x67c/0xe50 kernel/printk/printk.c:3269 console_flush_all kernel/printk/printk.c:3343 [inline] __console_flush_and_unlock kernel/printk/printk.c:3373 [inline] console_unlock+0x103/0x260 kernel/printk/printk.c:3413 vprintk_emit+0x407/0x6b0 kernel/printk/printk.c:2479 dev_vprintk_emit+0x394/0x3e0 drivers/base/core.c:4915 dev_printk_emit+0xd2/0x10d drivers/base/core.c:4926 __dev_printk+0xcb/0x100 drivers/base/core.c:4938 _dev_err+0xef/0x127 drivers/base/core.c:4981 urb_irq_callback.cold+0x41/0xfd drivers/input/misc/yealink.c:418 __usb_hcd_giveback_urb+0x38d/0x610 drivers/usb/core/hcd.c:1657 usb_hcd_giveback_urb+0x3ca/0x4a0 drivers/usb/core/hcd.c:1741 dummy_timer+0xda1/0x36c0 drivers/usb/gadget/udc/dummy_hcd.c:2005 __run_hrtimer kernel/time/hrtimer.c:1785 [inline] __hrtimer_run_queues+0x50e/0xa70 kernel/time/hrtimer.c:1849 hrtimer_run_softirq+0x17d/0x350 kernel/time/hrtimer.c:1866 handle_softirqs+0x1de/0x9d0 kernel/softirq.c:622 __do_softirq kernel/softirq.c:656 [inline] invoke_softirq kernel/softirq.c:496 [inline] __irq_exit_rcu+0xed/0x150 kernel/softirq.c:723 irq_exit_rcu+0x9/0x30 kernel/softirq.c:739 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1056 [inline] sysvec_apic_timer_interrupt+0x8f/0xb0 arch/x86/kernel/apic/apic.c:1056 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697 RIP: 0010:arch_atomic_read arch/x86/include/asm/atomic.h:23 [inline] RIP: 0010:raw_atomic_read include/linux/atomic/atomic-arch-fallback.h:457 [inline] RIP: 0010:rcu_is_watching_curr_cpu include/linux/context_tracking.h:128 [inline] RIP: 0010:rcu_is_watching+0x60/0xc0 kernel/rcu/tree.c:752 Code: 48 89 fa 48 c1 ea 03 80 3c 02 00 75 5c 48 03 1c ed e0 ab 1a 89 48 b8 00 00 00 00 00 fc ff df 48 89 da 48 c1 ea 03 0f b6 14 02 <48> 89 d8 83 e0 07 83 c0 03 38 d0 7c 04 84 d2 75 24 8b 03 c1 e8 02 RSP: 0018:ffffc90004fbfac8 EFLAGS: 00000a06 RAX: dffffc0000000000 RBX: ffff8881f5633968 RCX: 0000000000000002 RDX: 0000000000000000 RSI: ffffffff87afd2a0 RDI: ffffffff891aabe0 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000040000 R11: 0000000000000000 R12: 0000000000000002 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 trace_lock_acquire include/trace/events/lock.h:24 [inline] lock_acquire+0x317/0x380 kernel/locking/lockdep.c:5831 rcu_lock_acquire include/linux/rcupdate.h:312 [inline] rcu_read_lock include/linux/rcupdate.h:850 [inline] gc_worker+0x222/0x1630 net/netfilter/nf_conntrack_core.c:1546 process_one_work+0xa23/0x19a0 kernel/workqueue.c:3276 process_scheduled_works kernel/workqueue.c:3359 [inline] worker_thread+0x5ef/0xe50 kernel/workqueue.c:3440 kthread+0x370/0x450 kernel/kthread.c:436 ret_from_fork+0x6c3/0xcb0 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245