INFO: task kworker/0:7:8811 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kworker/0:7 state:D stack:21592 pid:8811 tgid:8811 ppid:2 task_flags:0x4208060 flags:0x00080000 Workqueue: events request_firmware_work_func Call Trace: context_switch kernel/sched/core.c:5510 [inline] __schedule+0x1325/0x47d0 kernel/sched/core.c:7234 __schedule_loop kernel/sched/core.c:7311 [inline] schedule+0xdd/0x2c0 kernel/sched/core.c:7326 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7383 __mutex_lock_common kernel/locking/mutex.c:726 [inline] __mutex_lock+0xccc/0x1bd0 kernel/locking/mutex.c:821 device_lock include/linux/device.h:1102 [inline] ath9k_hif_usb_firmware_fail drivers/net/wireless/ath/ath9k/hif_usb.c:1151 [inline] ath9k_hif_usb_firmware_cb+0x39e/0x510 drivers/net/wireless/ath/ath9k/hif_usb.c:1284 request_firmware_work_func+0x13f/0x440 drivers/base/firmware_loader/main.c:1164 process_one_work+0xa23/0x1940 kernel/workqueue.c:3322 process_scheduled_works kernel/workqueue.c:3405 [inline] worker_thread+0x5ef/0xe50 kernel/workqueue.c:3486 kthread+0x370/0x450 kernel/kthread.c:436 ret_from_fork+0x69a/0xc80 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Showing all locks held in the system: 1 lock held by khungtaskd/30: #0: ffffffff896e3000 ( rcu_read_lock ){....}-{1:3} , at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline] , at: rcu_read_lock include/linux/rcupdate.h:840 [inline] , at: debug_show_all_locks+0x3d/0x184 kernel/locking/lockdep.c:6775 2 locks held by getty/2921: #0: ffff8881123200a0 ( &tty->ldisc_sem ){++++}-{0:0} , at: tty_ldisc_ref_wait+0x24/0x80 drivers/tty/tty_ldisc.c:243 #1: ffffc900000452e8 ( &ldata->atomic_read_lock ){+.+.}-{4:4} , at: n_tty_read+0x419/0x14e0 drivers/tty/n_tty.c:2211 4 locks held by udevd/5209: #0: ffff88811ebd2998 ( &p->lock ){+.+.}-{4:4} , at: seq_read_iter+0xe1/0x1270 fs/seq_file.c:183 #1: ffff888136663c80 (&of->mutex#2){+.+.}-{4:4}, at: kernfs_seq_start+0x4f/0x2a0 fs/kernfs/file.c:165 #2: ffff888120ce8878 (kn->active#18){++++}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:73 [inline] ffff888120ce8878 (kn->active#18){++++}-{0:0}, at: kernfs_seq_start+0xbc/0x2a0 fs/kernfs/file.c:166 #3: ffff88811f81b1d8 (&dev->mutex){....}-{4:4}, at: device_lock_interruptible include/linux/device.h:1107 [inline] #3: ffff88811f81b1d8 (&dev->mutex){....}-{4:4}, at: manufacturer_show+0x26/0xa0 drivers/usb/core/sysfs.c:142 6 locks held by kworker/1:2/5216: #0: ffff888105aa3940 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work+0x12b1/0x1940 kernel/workqueue.c:3297 #1: ffffc9000215fd18 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work+0x988/0x1940 kernel/workqueue.c:3298 #2: ffff88810ab6d1d8 ( &dev->mutex ){....}-{4:4}, at: device_lock include/linux/device.h:1102 [inline] ){....}-{4:4}, at: hub_event+0x1bd/0x4af0 drivers/usb/core/hub.c:5899 #3: ffff88810af42560 (&port_dev->status_lock){+.+.}-{4:4} , at: usb_lock_port drivers/usb/core/hub.c:3252 [inline] , at: hub_port_connect drivers/usb/core/hub.c:5464 [inline] , at: hub_port_connect_change drivers/usb/core/hub.c:5707 [inline] , at: port_event drivers/usb/core/hub.c:5871 [inline] , at: hub_event+0x2bd2/0x4af0 drivers/usb/core/hub.c:5953 #4: ffff88810af01d60 ( hcd->address0_mutex ){+.+.}-{4:4}, at: hub_port_connect drivers/usb/core/hub.c:5465 [inline] ){+.+.}-{4:4}, at: hub_port_connect_change drivers/usb/core/hub.c:5707 [inline] ){+.+.}-{4:4}, at: port_event drivers/usb/core/hub.c:5871 [inline] ){+.+.}-{4:4}, at: hub_event+0x2bfb/0x4af0 drivers/usb/core/hub.c:5953 #5: ffff8881f57397a0 (&rq->__lock){-.-.}-{2:2} , at: raw_spin_rq_lock_nested kernel/sched/core.c:667 [inline] , at: raw_spin_rq_lock kernel/sched/sched.h:1653 [inline] , at: rq_lock kernel/sched/sched.h:1991 [inline] , at: __schedule+0x2dc/0x47d0 kernel/sched/core.c:7108 6 locks held by kworker/0:4/5233: 4 locks held by udevd/7194: #0: ffff8881141621b8 ( &p->lock ){+.+.}-{4:4} , at: seq_read_iter+0xe1/0x1270 fs/seq_file.c:183 #1: ffff888118e31c80 (&of->mutex#2){+.+.}-{4:4}, at: kernfs_seq_start+0x4f/0x2a0 fs/kernfs/file.c:165 #2: ffff88811514a1e8 (kn->active#18 ){++++}-{0:0} , at: kernfs_get_active_of fs/kernfs/file.c:73 [inline] , at: kernfs_seq_start+0xbc/0x2a0 fs/kernfs/file.c:166 #3: ffff88813595a1d8 ( &dev->mutex){....}-{4:4}, at: device_lock_interruptible include/linux/device.h:1107 [inline] &dev->mutex){....}-{4:4}, at: manufacturer_show+0x26/0xa0 drivers/usb/core/sysfs.c:142 6 locks held by kworker/0:0/8805: #0: ffff888105aa3940 ((wq_completion)usb_hub_wq ){+.+.}-{0:0} , at: process_one_work+0x12b1/0x1940 kernel/workqueue.c:3297 #1: ffffc900032e7d18 ((work_completion)(&hub->events) ){+.+.}-{0:0}, at: process_one_work+0x988/0x1940 kernel/workqueue.c:3298 #2: ffff88810a3551d8 (&dev->mutex ){....}-{4:4} , at: device_lock include/linux/device.h:1102 [inline] , at: hub_event+0x1bd/0x4af0 drivers/usb/core/hub.c:5899 #3: ffff88811f81b1d8 ( &dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1102 [inline] &dev->mutex){....}-{4:4}, at: __device_attach+0x7e/0x4d0 drivers/base/dd.c:1073 #4: ffff88811ff3e1a0 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1102 [inline] #4: ffff88811ff3e1a0 (&dev->mutex){....}-{4:4}, at: __device_attach+0x7e/0x4d0 drivers/base/dd.c:1073 #5: ffffffff8aa45b40 (register_mutex#3){+.+.}-{4:4}, at: class_mutex_constructor include/linux/mutex.h:253 [inline] #5: ffffffff8aa45b40 (register_mutex#3){+.+.}-{4:4}, at: usb_audio_probe+0x385/0x3b10 sound/usb/card.c:951 3 locks held by kworker/0:7/8811: #0: ffff88810006b140 ( (wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x12b1/0x1940 kernel/workqueue.c:3297 #1: ffffc900033d7d18 ((work_completion)(&fw_work->work)){+.+.}-{0:0}, at: process_one_work+0x988/0x1940 kernel/workqueue.c:3298 #2: ffff88810a7551d8 ( &dev->mutex ){....}-{4:4} , at: device_lock include/linux/device.h:1102 [inline] , at: ath9k_hif_usb_firmware_fail drivers/net/wireless/ath/ath9k/hif_usb.c:1151 [inline] , at: ath9k_hif_usb_firmware_cb+0x39e/0x510 drivers/net/wireless/ath/ath9k/hif_usb.c:1284 2 locks held by kworker/0:8/9011: #0: ffff8881f56397a0 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested kernel/sched/core.c:667 [inline] #0: ffff8881f56397a0 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock kernel/sched/sched.h:1653 [inline] #0: ffff8881f56397a0 (&rq->__lock){-.-.}-{2:2}, at: rq_lock kernel/sched/sched.h:1991 [inline] #0: ffff8881f56397a0 (&rq->__lock){-.-.}-{2:2}, at: __schedule+0x2dc/0x47d0 kernel/sched/core.c:7108 #1: ffffc90002cafd18 ((work_completion)(&(&d->rc_query_work)->work)#2){+.+.}-{0:0}, at: process_one_work+0x988/0x1940 kernel/workqueue.c:3298 ============================================= NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 30 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT(lazy) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026 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:122 nmi_trigger_cpumask_backtrace+0x21c/0x2a0 lib/nmi_backtrace.c:65 trigger_all_cpu_backtrace include/linux/nmi.h:162 [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:353 [inline] watchdog+0xcb1/0x1030 kernel/hung_task.c:561 kthread+0x370/0x450 kernel/kthread.c:436 ret_from_fork+0x69a/0xc80 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 5232 Comm: kworker/1:4 Not tainted syzkaller #0 PREEMPT(lazy) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026 Workqueue: events legacy_dvb_usb_read_remote_control RIP: 0010:mark_held_locks+0x2b/0x70 kernel/locking/lockdep.c:4318 Code: 87 50 0b 00 00 85 c0 7e 5a 41 55 49 89 fd 41 54 41 89 f4 55 31 ed 53 48 8d 9f 58 0b 00 00 0f b6 43 22 89 c2 83 e2 03 80 fa 01 <44> 89 e2 83 da ff a8 04 74 0f 48 89 de 4c 89 ef e8 90 f5 ff ff 85 RSP: 0018:ffffc900001a8bb8 EFLAGS: 00000097 RAX: 0000000000000004 RBX: ffff888118bfe558 RCX: 0000000000000000 RDX: 0000000000000000 RSI: 0000000000000002 RDI: ffff888118bfda00 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000001 R11: 0000000000000000 R12: 0000000000000002 R13: ffff888118bfda00 R14: 0000000000000011 R15: ffff888123018000 FS: 0000000000000000(0000) GS:ffff88826873e000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000001b2e70eff8 CR3: 00000001235d8000 CR4: 00000000003506f0 Call Trace: __trace_hardirqs_on_caller kernel/locking/lockdep.c:4343 [inline] lockdep_hardirqs_on_prepare kernel/locking/lockdep.c:4410 [inline] lockdep_hardirqs_on_prepare+0xb4/0x1b0 kernel/locking/lockdep.c:4362 trace_hardirqs_on+0x36/0x40 kernel/trace/trace_preemptirq.c:78 __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:178 [inline] _raw_spin_unlock_irqrestore+0x52/0x80 kernel/locking/spinlock.c:198 __debug_check_no_obj_freed lib/debugobjects.c:1180 [inline] debug_check_no_obj_freed+0x31f/0x630 lib/debugobjects.c:1201 __free_pages_prepare mm/page_alloc.c:1413 [inline] __free_frozen_pages+0x3cf/0xf50 mm/page_alloc.c:2950 __pagetable_free include/linux/mm.h:3695 [inline] pagetable_free include/linux/mm.h:3719 [inline] pagetable_dtor_free include/linux/mm.h:3818 [inline] __tlb_remove_table include/asm-generic/tlb.h:221 [inline] __tlb_remove_table_free mm/mmu_gather.c:228 [inline] tlb_remove_table_rcu+0x2cf/0x380 mm/mmu_gather.c:291 rcu_do_batch kernel/rcu/tree.c:2645 [inline] rcu_core+0x5a2/0x10d0 kernel/rcu/tree.c:2897 handle_softirqs+0x1dd/0x990 kernel/softirq.c:622 __do_softirq kernel/softirq.c:656 [inline] invoke_softirq kernel/softirq.c:496 [inline] __irq_exit_rcu+0x160/0x210 kernel/softirq.c:735 irq_exit_rcu+0x9/0x30 kernel/softirq.c:752 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1062 [inline] sysvec_apic_timer_interrupt+0x8f/0xb0 arch/x86/kernel/apic/apic.c:1062 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:674 RIP: 0010:console_trylock_spinning kernel/printk/printk.c:2039 [inline] RIP: 0010:vprintk_emit+0x553/0x6b0 kernel/printk/printk.c:2478 Code: 00 4d 85 ed 0f 85 1b 01 00 00 e8 08 1c 21 00 9c 5d 81 e5 00 02 00 00 31 ff 48 89 ee e8 96 16 21 00 48 85 ed 0f 85 27 01 00 00 e8 1b 21 00 45 31 c9 41 b8 01 00 00 00 31 c9 48 8d 05 00 00 00 RSP: 0018:ffffc9000219f9d8 EFLAGS: 00000293 RAX: 0000000000000000 RBX: 0000000000000017 RCX: ffffffff8192eeea RDX: ffff888118bfda00 RSI: ffffffff8192eef4 RDI: ffff888118bfda00 RBP: 0000000000000000 R08: 0000000000000007 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: 1ffff92000433f3d R13: 0000000000000200 R14: ffff888118bfbc00 R15: ffffc9000219faa0 _printk+0xcf/0x110 kernel/printk/printk.c:2504 m920x_read drivers/media/usb/dvb-usb/m920x.c:40 [inline] m920x_rc_query.cold+0x2b/0x30 drivers/media/usb/dvb-usb/m920x.c:188 legacy_dvb_usb_read_remote_control+0x10c/0x4f0 drivers/media/usb/dvb-usb/dvb-usb-remote.c:123 process_one_work+0xa23/0x1940 kernel/workqueue.c:3322 process_scheduled_works kernel/workqueue.c:3405 [inline] worker_thread+0x5ef/0xe50 kernel/workqueue.c:3486 kthread+0x370/0x450 kernel/kthread.c:436 ret_from_fork+0x69a/0xc80 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245