INFO: task kworker/1:3:5217 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kworker/1:3 state:D stack:21944 pid:5217 tgid:5217 ppid:2 task_flags:0x4208060 flags:0x00080000 Workqueue: usb_hub_wq hub_event Call Trace: context_switch kernel/sched/core.c:5388 [inline] __schedule+0x1138/0x47e0 kernel/sched/core.c:7189 __schedule_loop kernel/sched/core.c:7268 [inline] schedule+0xdd/0x390 kernel/sched/core.c:7283 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7340 __mutex_lock_common kernel/locking/mutex.c:726 [inline] __mutex_lock+0xced/0x1b10 kernel/locking/mutex.c:820 device_lock include/linux/device.h:1040 [inline] device_del+0xa0/0x9b0 drivers/base/core.c:3857 usb_disable_device+0x367/0x810 drivers/usb/core/message.c:1478 usb_disconnect+0x2e2/0x9a0 drivers/usb/core/hub.c:2345 hub_port_connect drivers/usb/core/hub.c:5407 [inline] hub_port_connect_change drivers/usb/core/hub.c:5707 [inline] port_event drivers/usb/core/hub.c:5871 [inline] hub_event+0x1d0c/0x4af0 drivers/usb/core/hub.c:5953 process_one_work+0xa0e/0x1980 kernel/workqueue.c:3314 process_scheduled_works kernel/workqueue.c:3397 [inline] worker_thread+0x5ef/0xe50 kernel/workqueue.c:3478 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 INFO: task kworker/0:6:5474 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kworker/0:6 state:D stack:21944 pid:5474 tgid:5474 ppid:2 task_flags:0x4288060 flags:0x00080000 Workqueue: events request_firmware_work_func Call Trace: context_switch kernel/sched/core.c:5388 [inline] __schedule+0x1138/0x47e0 kernel/sched/core.c:7189 __schedule_loop kernel/sched/core.c:7268 [inline] schedule+0xdd/0x390 kernel/sched/core.c:7283 lbs_wait_for_firmware_load+0x11e/0x1e0 drivers/net/wireless/marvell/libertas/firmware.c:116 lbs_remove_card+0x84/0x390 drivers/net/wireless/marvell/libertas/main.c:913 if_usb_disconnect+0xc5/0x270 drivers/net/wireless/marvell/libertas/if_usb.c:317 usb_unbind_interface+0x1dd/0x9e0 drivers/usb/core/driver.c:458 device_remove drivers/base/dd.c:621 [inline] device_remove+0x12a/0x180 drivers/base/dd.c:613 __device_release_driver drivers/base/dd.c:1352 [inline] device_release_driver_internal+0x44e/0x620 drivers/base/dd.c:1375 usb_driver_release_interface drivers/usb/core/driver.c:640 [inline] usb_forced_unbind_intf+0x1a4/0x240 drivers/usb/core/driver.c:1133 usb_reset_device+0x411/0xaa0 drivers/usb/core/hub.c:6404 if_usb_reset_device.isra.0+0x21e/0x290 drivers/net/wireless/marvell/libertas/if_usb.c:400 if_usb_prog_firmware.cold+0x161/0x192 drivers/net/wireless/marvell/libertas/if_usb.c:918 lbs_fw_loaded drivers/net/wireless/marvell/libertas/firmware.c:23 [inline] helper_firmware_cb drivers/net/wireless/marvell/libertas/firmware.c:80 [inline] helper_firmware_cb+0x202/0x2e0 drivers/net/wireless/marvell/libertas/firmware.c:64 request_firmware_work_func+0x13c/0x250 drivers/base/firmware_loader/main.c:1152 process_one_work+0xa0e/0x1980 kernel/workqueue.c:3314 process_scheduled_works kernel/workqueue.c:3397 [inline] worker_thread+0x5ef/0xe50 kernel/workqueue.c:3478 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: 6 locks held by kworker/1:0/23: #0: ffff88810669c940 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work+0x12d6/0x1980 kernel/workqueue.c:3289 #1: ffffc9000018fd18 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work+0x973/0x1980 kernel/workqueue.c:3290 #2: ffff88810bb741d8 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1040 [inline] #2: ffff88810bb741d8 (&dev->mutex){....}-{4:4}, at: hub_event+0x1bd/0x4af0 drivers/usb/core/hub.c:5899 #3: ffff88813dc661d8 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1040 [inline] #3: ffff88813dc661d8 (&dev->mutex){....}-{4:4}, at: __device_attach+0x7e/0x4d0 drivers/base/dd.c:1076 #4: ffff88812269f1a0 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1040 [inline] #4: ffff88812269f1a0 (&dev->mutex){....}-{4:4}, at: __device_attach+0x7e/0x4d0 drivers/base/dd.c:1076 #5: ffff888114041a58 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1040 [inline] #5: ffff888114041a58 (&dev->mutex){....}-{4:4}, at: __device_attach+0x7e/0x4d0 drivers/base/dd.c:1076 1 lock held by khungtaskd/29: #0: ffffffff896de960 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline] #0: ffffffff896de960 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline] #0: ffffffff896de960 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x3d/0x184 kernel/locking/lockdep.c:6775 2 locks held by getty/2918: #0: ffff8881162db0a0 (&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+0x419/0x14f0 drivers/tty/n_tty.c:2211 5 locks held by kworker/1:3/5217: #0: ffff88810669c940 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work+0x12d6/0x1980 kernel/workqueue.c:3289 #1: ffffc90002d0fd18 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work+0x973/0x1980 kernel/workqueue.c:3290 #2: ffff88810bb041d8 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1040 [inline] #2: ffff88810bb041d8 (&dev->mutex){....}-{4:4}, at: hub_event+0x1bd/0x4af0 drivers/usb/core/hub.c:5899 #3: ffff88811f63f1d8 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1040 [inline] #3: ffff88811f63f1d8 (&dev->mutex){....}-{4:4}, at: usb_disconnect+0x10a/0x9a0 drivers/usb/core/hub.c:2336 #4: ffff88811e9a51a0 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1040 [inline] (&dev->mutex){....}-{4:4}, at: device_del+0xa0/0x9b0 drivers/base/core.c:3857 6 locks held by kworker/1:4/5228: #0: ffff88810669c940 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work+0x12d6/0x1980 kernel/workqueue.c:3289 #1: ffffc90002c8fd18 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work+0x973/0x1980 kernel/workqueue.c:3290 #2: ffff88810b71c1d8 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1040 [inline] #2: ffff88810b71c1d8 (&dev->mutex){....}-{4:4}, at: hub_event+0x1bd/0x4af0 drivers/usb/core/hub.c:5899 #3: ffff888104eff1d8 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1040 [inline] #3: ffff888104eff1d8 (&dev->mutex){....}-{4:4}, at: __device_attach+0x7e/0x4d0 drivers/base/dd.c:1076 #4: ffff88813dc671a0 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1040 [inline] #4: ffff88813dc671a0 (&dev->mutex){....}-{4:4}, at: __device_attach+0x7e/0x4d0 drivers/base/dd.c:1076 #5: ffff88813a101a58 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1040 [inline] #5: ffff88813a101a58 (&dev->mutex){....}-{4:4}, at: __device_attach+0x7e/0x4d0 drivers/base/dd.c:1076 2 locks held by kworker/1:6/5248: 3 locks held by kworker/0:6/5474: #0: ffff88810006b140 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x12d6/0x1980 kernel/workqueue.c:3289 #1: ffffc90004117d18 ((work_completion)(&fw_work->work)){+.+.}-{0:0}, at: process_one_work+0x973/0x1980 kernel/workqueue.c:3290 #2: ffff88811e9a51a0 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1040 [inline] #2: ffff88811e9a51a0 (&dev->mutex){....}-{4:4}, at: __device_driver_lock drivers/base/dd.c:1174 [inline] #2: ffff88811e9a51a0 (&dev->mutex){....}-{4:4}, at: device_release_driver_internal+0xb2/0x620 drivers/base/dd.c:1372 1 lock held by udevd/8921: #0: ffff8881f56396e0 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested kernel/sched/core.c:652 [inline] #0: ffff8881f56396e0 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock kernel/sched/sched.h:1624 [inline] #0: ffff8881f56396e0 (&rq->__lock){-.-.}-{2:2}, at: rq_lock kernel/sched/sched.h:1968 [inline] #0: ffff8881f56396e0 (&rq->__lock){-.-.}-{2:2}, at: __schedule+0x2bc/0x47e0 kernel/sched/core.c:7064 2 locks held by syz.1.1026/8985: ============================================= NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 29 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:113 nmi_trigger_cpumask_backtrace+0x1d7/0x230 lib/nmi_backtrace.c:62 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: 5248 Comm: kworker/1:6 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:io_serial_in+0x87/0xb0 drivers/tty/serial/8250/8250_port.c:402 Code: ef 8f 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 a8 aa f5 fe eb a2 e8 31 ab RSP: 0000:ffffc90002dcf690 EFLAGS: 00000006 RAX: dffffc0000000005 RBX: 00000000000003f9 RCX: 0000000000000000 RDX: 00000000000003f9 RSI: ffffffff8322f5d0 RDI: ffffffff941da800 RBP: ffffffff941da7c0 R08: 0000000000000001 R09: 000000000000001f R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000 R13: ffffffff941daa80 R14: ffffffff941da810 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff8882687a5000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000001b2e8e4ff8 CR3: 00000001333a6000 CR4: 00000000003506f0 Call Trace: serial_port_in include/linux/serial_core.h:806 [inline] serial8250_console_write+0x246/0x1900 drivers/tty/serial/8250/8250_port.c:3324 console_emit_next_record kernel/printk/printk.c:3183 [inline] console_flush_one_record+0x790/0xe50 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 _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+0xa0e/0x1980 kernel/workqueue.c:3314 process_scheduled_works kernel/workqueue.c:3397 [inline] worker_thread+0x5ef/0xe50 kernel/workqueue.c:3478 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