INFO: task kworker/0:4:5233 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kworker/0:4 state:D stack:22040 pid:5233 tgid:5233 ppid:2 task_flags:0x4208060 flags:0x00080000 Workqueue: events request_firmware_work_func Call Trace: context_switch kernel/sched/core.c:5260 [inline] __schedule+0xeb0/0x3e50 kernel/sched/core.c:6867 __schedule_loop kernel/sched/core.c:6949 [inline] schedule+0xdd/0x390 kernel/sched/core.c:6964 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7021 __mutex_lock_common kernel/locking/mutex.c:692 [inline] __mutex_lock+0xc9a/0x1b90 kernel/locking/mutex.c:776 device_lock include/linux/device.h:895 [inline] ath9k_hif_usb_firmware_fail drivers/net/wireless/ath/ath9k/hif_usb.c:1161 [inline] ath9k_hif_usb_firmware_cb+0x3b2/0x530 drivers/net/wireless/ath/ath9k/hif_usb.c:1294 request_firmware_work_func+0x13c/0x250 drivers/base/firmware_loader/main.c:1152 process_one_work+0x9c2/0x1840 kernel/workqueue.c:3257 process_scheduled_works kernel/workqueue.c:3340 [inline] worker_thread+0x5da/0xe40 kernel/workqueue.c:3421 kthread+0x3b3/0x730 kernel/kthread.c:463 ret_from_fork+0x6c3/0xa20 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246 Showing all locks held in the system: 1 lock held by khungtaskd/30: #0: ffffffff894da3a0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff894da3a0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline] #0: ffffffff894da3a0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x3d/0x184 kernel/locking/lockdep.c:6775 4 locks held by kworker/u8:14/2341: #0: ffff888100ac4948 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work+0x11ae/0x1840 kernel/workqueue.c:3232 #1: ffffc900035efca8 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work+0x927/0x1840 kernel/workqueue.c:3233 #2: ffffffff8a8b49b0 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xab/0x900 net/core/net_namespace.c:670 #3: ffffffff8a8ccfe8 (rtnl_mutex){+.+.}-{4:4}, at: default_device_exit_batch+0x90/0xc60 net/core/dev.c:13037 2 locks held by getty/2925: #0: ffff8881086f70a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x24/0x80 drivers/tty/tty_ldisc.c:243 #1: ffffc900000452f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x419/0x1500 drivers/tty/n_tty.c:2211 5 locks held by kworker/0:3/5232: 3 locks held by kworker/0:4/5233: #0: ffff888100071948 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x11ae/0x1840 kernel/workqueue.c:3232 #1: ffffc90002a8fca8 ((work_completion)(&fw_work->work)){+.+.}-{0:0}, at: process_one_work+0x927/0x1840 kernel/workqueue.c:3233 #2: ffff88810af29198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:895 [inline] #2: ffff88810af29198 (&dev->mutex){....}-{4:4}, at: ath9k_hif_usb_firmware_fail drivers/net/wireless/ath/ath9k/hif_usb.c:1161 [inline] #2: ffff88810af29198 (&dev->mutex){....}-{4:4}, at: ath9k_hif_usb_firmware_cb+0x3b2/0x530 drivers/net/wireless/ath/ath9k/hif_usb.c:1294 4 locks held by kworker/0:5/5287: 3 locks held by kworker/1:6/5338: #0: ffff888100071948 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x11ae/0x1840 kernel/workqueue.c:3232 #1: ffffc90002c27ca8 (free_ipc_work){+.+.}-{0:0}, at: process_one_work+0x927/0x1840 kernel/workqueue.c:3233 #2: ffffffff894e6b78 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock+0x19e/0x3c0 kernel/rcu/tree_exp.h:343 7 locks held by kworker/0:2/10015: 4 locks held by kworker/1:7/11236: #0: ffff888105287548 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work+0x11ae/0x1840 kernel/workqueue.c:3232 #1: ffffc90007257ca8 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work+0x927/0x1840 kernel/workqueue.c:3233 #2: ffff88810abe1198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:895 [inline] #2: ffff88810abe1198 (&dev->mutex){....}-{4:4}, at: hub_event+0x1bd/0x4af0 drivers/usb/core/hub.c:5899 #3: ffffffff8abb6b48 (uevent_sock_mutex){+.+.}-{4:4}, at: uevent_net_broadcast_untagged lib/kobject_uevent.c:317 [inline] #3: ffffffff8abb6b48 (uevent_sock_mutex){+.+.}-{4:4}, at: kobject_uevent_net_broadcast lib/kobject_uevent.c:410 [inline] #3: ffffffff8abb6b48 (uevent_sock_mutex){+.+.}-{4:4}, at: kobject_uevent_env+0xba8/0x18b0 lib/kobject_uevent.c:608 1 lock held by syz.5.982/11292: #0: ffffffff8abb6b48 (uevent_sock_mutex){+.+.}-{4:4}, at: uevent_net_broadcast_untagged lib/kobject_uevent.c:317 [inline] #0: ffffffff8abb6b48 (uevent_sock_mutex){+.+.}-{4:4}, at: kobject_uevent_net_broadcast lib/kobject_uevent.c:410 [inline] #0: ffffffff8abb6b48 (uevent_sock_mutex){+.+.}-{4:4}, at: kobject_uevent_env+0xba8/0x18b0 lib/kobject_uevent.c:608 2 locks held by syz.8.984/11299: #0: ffff888109fecdc0 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:895 [inline] #0: ffff888109fecdc0 (&dev->mutex){....}-{4:4}, at: __device_driver_lock drivers/base/dd.c:1104 [inline] #0: ffff888109fecdc0 (&dev->mutex){....}-{4:4}, at: __driver_attach+0x20c/0x5c0 drivers/base/dd.c:1224 #1: ffffffff8abb6b48 (uevent_sock_mutex){+.+.}-{4:4}, at: uevent_net_broadcast_untagged lib/kobject_uevent.c:317 [inline] #1: ffffffff8abb6b48 (uevent_sock_mutex){+.+.}-{4:4}, at: kobject_uevent_net_broadcast lib/kobject_uevent.c:410 [inline] #1: ffffffff8abb6b48 (uevent_sock_mutex){+.+.}-{4:4}, at: kobject_uevent_env+0xba8/0x18b0 lib/kobject_uevent.c:608 2 locks held by syz.7.985/11302: #0: ffff888109fe8dc0 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:895 [inline] #0: ffff888109fe8dc0 (&dev->mutex){....}-{4:4}, at: __device_driver_lock drivers/base/dd.c:1104 [inline] #0: ffff888109fe8dc0 (&dev->mutex){....}-{4:4}, at: __driver_attach+0x20c/0x5c0 drivers/base/dd.c:1224 #1: ffffffff8abb6b48 (uevent_sock_mutex){+.+.}-{4:4}, at: uevent_net_broadcast_untagged lib/kobject_uevent.c:317 [inline] #1: ffffffff8abb6b48 (uevent_sock_mutex){+.+.}-{4:4}, at: kobject_uevent_net_broadcast lib/kobject_uevent.c:410 [inline] #1: ffffffff8abb6b48 (uevent_sock_mutex){+.+.}-{4:4}, at: kobject_uevent_env+0xba8/0x18b0 lib/kobject_uevent.c:608 7 locks held by kworker/0:7/11307: 2 locks held by syz-executor/11319: #0: ffffffff8a8b49b0 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x41e/0x780 net/core/net_namespace.c:577 #1: ffffffff8a8ccfe8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] #1: ffffffff8a8ccfe8 (rtnl_mutex){+.+.}-{4:4}, at: register_netdevice_notifier_net+0x23/0xb0 net/core/dev.c:2096 2 locks held by syz-executor/11331: #0: ffffffff8a8b49b0 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x41e/0x780 net/core/net_namespace.c:577 #1: ffffffff8a8ccfe8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] #1: ffffffff8a8ccfe8 (rtnl_mutex){+.+.}-{4:4}, at: register_netdevice_notifier_net+0x23/0xb0 net/core/dev.c:2096 2 locks held by syz-executor/11333: #0: ffffffff8a8b49b0 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x41e/0x780 net/core/net_namespace.c:577 #1: ffffffff8a8ccfe8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] #1: ffffffff8a8ccfe8 (rtnl_mutex){+.+.}-{4:4}, at: register_netdevice_notifier_net+0x23/0xb0 net/core/dev.c:2096 2 locks held by syz-executor/11335: #0: ffffffff8a8b49b0 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x41e/0x780 net/core/net_namespace.c:577 #1: ffffffff8a8ccfe8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] #1: ffffffff8a8ccfe8 (rtnl_mutex){+.+.}-{4:4}, at: register_netdevice_notifier_net+0x23/0xb0 net/core/dev.c:2096 1 lock held by syz-executor/11370: #0: ffffffff894e6b78 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock+0x19e/0x3c0 kernel/rcu/tree_exp.h:343 ============================================= 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 10/25/2025 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+0xcc3/0xfe0 kernel/hung_task.c:515 kthread+0x3b3/0x730 kernel/kthread.c:463 ret_from_fork+0x6c3/0xa20 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246 Sending NMI from CPU 1 to CPUs 0: cdc_wdm 6-1:1.0: Stall on int endpoint NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 11307 Comm: kworker/0:7 Not tainted syzkaller #0 PREEMPT(voluntary) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 Workqueue: events free_obj_work RIP: 0010:check_kcov_mode kernel/kcov.c:183 [inline] RIP: 0010:write_comp_data+0x36/0x90 kernel/kcov.c:246 Code: f1 49 89 d2 65 48 8b 3d 10 2b 1a 0b a9 00 01 ff 00 74 1b f6 c4 01 74 07 a9 00 00 ff 00 74 05 e9 c0 34 a5 05 8b 87 64 15 00 00 <85> c0 74 f1 8b 87 40 15 00 00 83 f8 03 75 e6 48 8b 87 48 15 00 00 RSP: 0018:ffffc90000006f98 EFLAGS: 00000046 RAX: 0000000000000000 RBX: ffffffff876a8c62 RCX: ffffffff87500fb5 RDX: 0000000000000015 RSI: 0000000000000010 RDI: ffff88810536ba80 RBP: ffffc90000007040 R08: 0000000000000001 R09: 0000000000000010 R10: 0000000000000015 R11: 0000000000295408 R12: 0000000000000015 R13: ffffc900000070d0 R14: ffffffff876a8c61 R15: dffffc0000000000 FS: 0000000000000000(0000) GS:ffff88826896a000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00005637f2a99fd8 CR3: 0000000117388000 CR4: 00000000003506f0 Call Trace: spec_flag lib/vsprintf.c:2639 [inline] format_decode+0x275/0xcd0 lib/vsprintf.c:2704 vsnprintf+0x1c0/0x1240 lib/vsprintf.c:2889 sprintf+0xcc/0x100 lib/vsprintf.c:3110 print_time kernel/printk/printk.c:1357 [inline] info_print_prefix+0x25a/0x350 kernel/printk/printk.c:1383 record_print_text+0x143/0x3c0 kernel/printk/printk.c:1432 printk_get_next_message+0x2d1/0x6c0 kernel/printk/printk.c:3018 console_emit_next_record kernel/printk/printk.c:3083 [inline] console_flush_one_record+0x67c/0xe50 kernel/printk/printk.c:3215 console_flush_all kernel/printk/printk.c:3289 [inline] __console_flush_and_unlock kernel/printk/printk.c:3319 [inline] console_unlock+0x103/0x260 kernel/printk/printk.c:3359 vprintk_emit+0x407/0x6b0 kernel/printk/printk.c:2426 dev_vprintk_emit+0x394/0x3e0 drivers/base/core.c:4914 dev_printk_emit+0xd2/0x10d drivers/base/core.c:4925 __dev_printk+0xcb/0x100 drivers/base/core.c:4937 _dev_err+0xef/0x127 drivers/base/core.c:4980 wdm_int_callback+0x981/0xa80 drivers/usb/class/cdc-wdm.c:270 __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+0xd85/0x3670 drivers/usb/gadget/udc/dummy_hcd.c:1995 __run_hrtimer kernel/time/hrtimer.c:1777 [inline] __hrtimer_run_queues+0x516/0x990 kernel/time/hrtimer.c:1841 hrtimer_run_softirq+0x17d/0x350 kernel/time/hrtimer.c:1858 handle_softirqs+0x1dd/0x8f0 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:orc_ip arch/x86/kernel/unwind_orc.c:81 [inline] RIP: 0010:__orc_find+0x70/0xf0 arch/x86/kernel/unwind_orc.c:103 Code: ec 72 4e 4c 89 e2 48 29 ea 48 89 d6 48 c1 ea 3f 48 c1 fe 02 48 01 f2 48 d1 fa 48 8d 5c 95 00 48 89 da 48 c1 ea 03 0f b6 34 0a <48> 89 da 83 e2 07 83 c2 03 40 38 f2 7c 05 40 84 f6 75 4b 48 63 13 RSP: 0018:ffffc900073e7640 EFLAGS: 00000a07 RAX: ffffffff8b2f2c58 RBX: ffffffff8ada067c RCX: dffffc0000000000 RDX: 1ffffffff15b40cf RSI: 0000000000000000 RDI: ffffffff8ada067c RBP: ffffffff8ada067c R08: ffffffff8b2f2c5e R09: 0000000000000007 R10: 0000000000000200 R11: 0000000000007cd4 R12: ffffffff8ada067c R13: ffffffff817cd421 R14: ffffffff8ada067c R15: ffffffff8ada067c orc_find arch/x86/kernel/unwind_orc.c:238 [inline] unwind_next_frame+0x2ec/0x1ea0 arch/x86/kernel/unwind_orc.c:510 arch_stack_walk+0x94/0xf0 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0x8e/0xc0 kernel/stacktrace.c:122 kasan_save_stack+0x30/0x50 mm/kasan/common.c:57 kasan_save_track+0x14/0x30 mm/kasan/common.c:78 kasan_save_free_info+0x3b/0x70 mm/kasan/generic.c:584 poison_slab_object mm/kasan/common.c:253 [inline] __kasan_slab_free+0x43/0x70 mm/kasan/common.c:285 kasan_slab_free include/linux/kasan.h:235 [inline] slab_free_hook mm/slub.c:2540 [inline] slab_free mm/slub.c:6670 [inline] kmem_cache_free+0x124/0x6d0 mm/slub.c:6781 free_object_list.isra.0+0xf8/0x2a0 lib/debugobjects.c:326 free_obj_work+0x19d/0x3d0 lib/debugobjects.c:513 process_one_work+0x9c2/0x1840 kernel/workqueue.c:3257 process_scheduled_works kernel/workqueue.c:3340 [inline] worker_thread+0x5da/0xe40 kernel/workqueue.c:3421 kthread+0x3b3/0x730 kernel/kthread.c:463 ret_from_fork+0x6c3/0xa20 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246