INFO: task kworker/0:7:5242 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:20600 pid:5242 tgid:5242 ppid:2 task_flags:0x4288060 flags:0x00080000 Workqueue: events request_firmware_work_func Call Trace: context_switch kernel/sched/core.c:5520 [inline] __schedule+0x1325/0x47e0 kernel/sched/core.c:7270 __schedule_loop kernel/sched/core.c:7347 [inline] schedule+0xdd/0x2c0 kernel/sched/core.c:7362 lbs_wait_for_firmware_load+0x11e/0x1e0 drivers/net/wireless/marvell/libertas/firmware.c:117 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:461 device_remove drivers/base/dd.c:618 [inline] device_remove+0x12a/0x180 drivers/base/dd.c:610 __device_release_driver drivers/base/dd.c:1349 [inline] device_release_driver_internal+0x44e/0x620 drivers/base/dd.c:1372 usb_driver_release_interface drivers/usb/core/driver.c:643 [inline] usb_forced_unbind_intf+0x1a4/0x240 drivers/usb/core/driver.c:1137 usb_reset_device+0x411/0xaa0 drivers/usb/core/hub.c:6417 if_usb_reset_device.isra.0+0x21e/0x290 drivers/net/wireless/marvell/libertas/if_usb.c:400 if_usb_prog_firmware+0x626/0xef0 drivers/net/wireless/marvell/libertas/if_usb.c:889 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+0x1f7/0x2d0 drivers/net/wireless/marvell/libertas/firmware.c:64 request_firmware_work_func+0x13f/0x440 drivers/base/firmware_loader/main.c:1164 process_one_work+0xac7/0x1b10 kernel/workqueue.c:3387 process_scheduled_works kernel/workqueue.c:3470 [inline] worker_thread+0x5ef/0xe50 kernel/workqueue.c:3551 kthread+0x373/0x450 kernel/kthread.c:436 ret_from_fork+0x69f/0xc90 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: locks held by kworker/0:0/9: 7, last CPU#0: #0: ffff888102ac5540 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work+0x1466/0x1b10 kernel/workqueue.c:3362 #1: ffffc9000009fd18 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work+0xa2c/0x1b10 kernel/workqueue.c:3363 #2: ffff888109fdd1d8 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1104 [inline] #2: ffff888109fdd1d8 (&dev->mutex){....}-{4:4}, at: hub_event+0x1bb/0x4510 drivers/usb/core/hub.c:5912 #3: ffff88811e49f1d8 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1104 [inline] #3: ffff88811e49f1d8 (&dev->mutex){....}-{4:4}, at: __device_attach+0x7e/0x4d0 drivers/base/dd.c:1073 #4: ffff888114d361a0 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1104 [inline] #4: ffff888114d361a0 (&dev->mutex){....}-{4:4}, at: __device_attach+0x7e/0x4d0 drivers/base/dd.c:1073 #5: ffffffff8a8091a0 (dvbdev_register_lock){+.+.}-{4:4}, at: dvb_register_device+0x47/0x1e20 drivers/media/dvb-core/dvbdev.c:462 #6: ffffffff8a0b4320 (gdp_mutex){+.+.}-{4:4}, at: get_device_parent+0xff/0x4c0 drivers/base/core.c:3338 locks held by pr/ttyS0/15: 2, last CPU#1: #0: ffffffff898d0c78 (console_srcu){....}-{0:0}, at: rcu_try_lock_acquire include/linux/rcupdate.h:314 [inline] #0: ffffffff898d0c78 (console_srcu){....}-{0:0}, at: srcu_read_lock_nmisafe include/linux/srcu.h:439 [inline] #0: ffffffff898d0c78 (console_srcu){....}-{0:0}, at: console_srcu_read_lock+0x49/0x60 kernel/printk/printk.c:291 #1: ffffffff944867f8 (&port_lock_key){-.-.}-{3:3}, at: __uart_port_lock_irqsave include/linux/serial_core.h:613 [inline] #1: ffffffff944867f8 (&port_lock_key){-.-.}-{3:3}, at: univ8250_console_device_lock+0x64/0xc0 drivers/tty/serial/8250/8250_core.c:413 locks held by khungtaskd/31: 1, last CPU#0: #0: ffffffff898e49a0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline] #0: ffffffff898e49a0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #0: ffffffff898e49a0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x3d/0x184 kernel/locking/lockdep.c:6837 locks held by getty/2925: 2, on CPU#0: #0: ffff8881120800a0 (&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 locks held by udevd/5222: 4, on CPU#1: #0: ffff88813513d878 (&p->lock){+.+.}-{4:4}, at: seq_read_iter+0xe1/0x1270 fs/seq_file.c:183 #1: ffff8881149f9c80 (&of->mutex#2){+.+.}-{4:4}, at: kernfs_seq_start+0x4f/0x2a0 fs/kernfs/file.c:165 #2: ffff888114cc8008 (kn->active#25){++++}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:73 [inline] #2: ffff888114cc8008 (kn->active#25){++++}-{0:0}, at: kernfs_seq_start+0xbc/0x2a0 fs/kernfs/file.c:166 #3: ffff88811e49f1d8 (&dev->mutex){....}-{4:4}, at: device_lock_interruptible include/linux/device.h:1109 [inline] #3: ffff88811e49f1d8 (&dev->mutex){....}-{4:4}, at: manufacturer_show+0x26/0xa0 drivers/usb/core/sysfs.c:142 locks held by kworker/0:5/5238: 3, on CPU#0: #0: ffff88810006a140 ((wq_completion)events_freezable){+.+.}-{0:0}, at: process_one_work+0x1466/0x1b10 kernel/workqueue.c:3362 #1: ffffc9000317fd18 ((work_completion)(&hcd->wakeup_work)){+.+.}-{0:0}, at: process_one_work+0xa2c/0x1b10 kernel/workqueue.c:3363 #2: ffff88810a7d51d8 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1104 [inline] #2: ffff88810a7d51d8 (&dev->mutex){....}-{4:4}, at: usb_remote_wakeup+0x23/0x100 drivers/usb/core/hub.c:3899 locks held by kworker/0:7/5242: 3, on CPU#0: #0: ffff88810006b140 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x1466/0x1b10 kernel/workqueue.c:3362 #1: ffffc900031bfd18 ((work_completion)(&fw_work->work)){+.+.}-{0:0}, at: process_one_work+0xa2c/0x1b10 kernel/workqueue.c:3363 #2: ffff88813c9541a0 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1104 [inline] #2: ffff88813c9541a0 (&dev->mutex){....}-{4:4}, at: __device_driver_lock drivers/base/dd.c:1171 [inline] #2: ffff88813c9541a0 (&dev->mutex){....}-{4:4}, at: device_release_driver_internal+0xb2/0x620 drivers/base/dd.c:1369 locks held by kworker/0:9/11220: 5, on CPU#0: #0: ffff888102ac5540 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work+0x1466/0x1b10 kernel/workqueue.c:3362 #1: ffffc90003e2fd18 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work+0xa2c/0x1b10 kernel/workqueue.c:3363 #2: ffff88810ab151d8 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1104 [inline] #2: ffff88810ab151d8 (&dev->mutex){....}-{4:4}, at: hub_event+0x1bb/0x4510 drivers/usb/core/hub.c:5912 #3: ffff88813c8091d8 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1104 [inline] #3: ffff88813c8091d8 (&dev->mutex){....}-{4:4}, at: usb_disconnect+0x10a/0x9a0 drivers/usb/core/hub.c:2341 #4: ffff88813c9541a0 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1104 [inline] #4: ffff88813c9541a0 (&dev->mutex){....}-{4:4}, at: device_del+0xa0/0x9b0 drivers/base/core.c:3927 locks held by kworker/1:6/12137: 5, on CPU#1: #0: ffff888102ac5540 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work+0x1466/0x1b10 kernel/workqueue.c:3362 #1: ffffc90013b2fd18 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work+0xa2c/0x1b10 kernel/workqueue.c:3363 #2: ffff88810a7451d8 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1104 [inline] #2: ffff88810a7451d8 (&dev->mutex){....}-{4:4}, at: hub_event+0x1bb/0x4510 drivers/usb/core/hub.c:5912 #3: ffff88810a7d2560 (&port_dev->status_lock){+.+.}-{4:4}, at: usb_lock_port drivers/usb/core/hub.c:3265 [inline] #3: ffff88810a7d2560 (&port_dev->status_lock){+.+.}-{4:4}, at: hub_event+0x5ab/0x4510 drivers/usb/core/hub.c:5965 #4: ffff88810a7d3090 (&hub->status_mutex){+.+.}-{4:4}, at: hub_ext_port_status+0x5e/0x690 drivers/usb/core/hub.c:623 locks held by syz-executor/12538: 2, last CPU#1: #0: ffff8881103df6c8 (vm_lock){++++}-{0:0}, at: lock_vma_under_rcu+0x11d/0x590 mm/mmap_lock.c:310 #1: ffffffff898e49a0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline] #1: ffffffff898e49a0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #1: ffffffff898e49a0 (rcu_read_lock){....}-{1:3}, at: count_memcg_events_mm.constprop.0+0x2f/0x2a0 include/linux/memcontrol.h:990 ============================================= NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 31 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT(lazy) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026 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:123 nmi_trigger_cpumask_backtrace+0x21f/0x2a0 lib/nmi_backtrace.c:66 trigger_all_cpu_backtrace include/linux/nmi.h:164 [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+0x373/0x450 kernel/kthread.c:436 ret_from_fork+0x69f/0xc90 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: 15 Comm: pr/ttyS0 Not tainted syzkaller #0 PREEMPT(lazy) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026 RIP: 0010:io_serial_in+0x87/0xb0 drivers/tty/serial/8250/8250_port.c:410 Code: 67 83 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 e9 7d ea 58 04 e8 88 34 ee fe eb a2 e8 11 35 RSP: 0018:ffffc900000ff968 EFLAGS: 00000002 RAX: dffffc0000000000 RBX: 00000000000003fd RCX: 0000000000000000 RDX: 00000000000003fd RSI: ffffffff83318170 RDI: ffffffff94486820 RBP: ffffffff944867e0 R08: 0000000000000001 R09: 000000000000001f R10: 0000000000000000 R11: 205d313354202020 R12: 0000000000000000 R13: 0000000000000020 R14: fffffbfff2890d59 R15: dffffc0000000000 FS: 0000000000000000(0000) GS:ffff8882684e8000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007ff48c0bd558 CR3: 0000000118ea4000 CR4: 00000000003506f0 Call Trace: serial_in drivers/tty/serial/8250/8250.h:128 [inline] serial_lsr_in drivers/tty/serial/8250/8250.h:150 [inline] wait_for_lsr+0x13a/0x210 drivers/tty/serial/8250/8250_port.c:2013 serial8250_fifo_wait_for_lsr_thre+0x5f/0xd0 drivers/tty/serial/8250/8250_port.c:3270 __serial8250_console_fifo_write+0x23c/0x290 drivers/tty/serial/8250/8250_port.c:3372 serial8250_console_fifo_write drivers/tty/serial/8250/8250_port.c:3378 [inline] __serial8250_console_write drivers/tty/serial/8250/8250_port.c:3429 [inline] serial8250_console_write+0xf46/0x1330 drivers/tty/serial/8250/8250_port.c:3493 nbcon_emit_next_record+0x8f7/0xa70 kernel/printk/nbcon.c:1070 nbcon_emit_one+0x1a8/0x2b0 kernel/printk/nbcon.c:1157 nbcon_kthread_func+0x613/0x7d0 kernel/printk/nbcon.c:1271 kthread+0x373/0x450 kernel/kthread.c:436 ret_from_fork+0x69f/0xc90 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245