syzbot

INFO: task kworker/1:4:7476 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/1:4     state:D stack:22648 pid:7476  tgid:7476  ppid:2      task_flags:0x4288060 flags:0x00080000
Workqueue: events request_firmware_work_func

Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5256 [inline]
 __schedule+0x145d/0x4a00 kernel/sched/core.c:6863
 __schedule_loop kernel/sched/core.c:6945 [inline]
 schedule+0xe7/0x3a0 kernel/sched/core.c:6960
 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+0xaf/0x2e0 drivers/net/wireless/marvell/libertas/if_usb.c:316
 usb_unbind_interface+0x1dd/0x9e0 drivers/usb/core/driver.c:458
 device_remove drivers/base/dd.c:571 [inline]
 device_remove+0x125/0x170 drivers/base/dd.c:563
 __device_release_driver drivers/base/dd.c:1282 [inline]
 device_release_driver_internal+0x44b/0x620 drivers/base/dd.c:1305
 usb_driver_release_interface drivers/usb/core/driver.c:640 [inline]
 usb_forced_unbind_intf+0x144/0x280 drivers/usb/core/driver.c:1133
 usb_reset_device+0x439/0xad0 drivers/usb/core/hub.c:6404
 if_usb_reset_device.isra.0+0x215/0x280 drivers/net/wireless/marvell/libertas/if_usb.c:400
 if_usb_prog_firmware+0x63c/0x10c0 drivers/net/wireless/marvell/libertas/if_usb.c:877
 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+0x1f8/0x2e0 drivers/net/wireless/marvell/libertas/firmware.c:64
 request_firmware_work_func+0x13c/0x250 drivers/base/firmware_loader/main.c:1152
 process_one_work+0x9ba/0x1b20 kernel/workqueue.c:3257
 process_scheduled_works kernel/workqueue.c:3340 [inline]
 worker_thread+0x6c8/0xf10 kernel/workqueue.c:3421
 kthread+0x3c5/0x780 kernel/kthread.c:463
 ret_from_fork+0x74f/0xa30 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246
 </TASK>

Showing all locks held in the system:
6 locks held by kworker/1:0/23:
1 lock held by khungtaskd/30:
 #0: ffffffff892cd760 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
 #0: ffffffff892cd760 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline]
 #0: ffffffff892cd760 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x36/0x1c0 kernel/locking/lockdep.c:6775
2 locks held by getty/2927:
 #0: ffff888115ce80a0 (&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+0x41b/0x1510 drivers/tty/n_tty.c:2211
5 locks held by kworker/0:5/7449:
4 locks held by udevd/7457:
 #0: ffff888134ef1b08 (&p->lock){+.+.}-{4:4}, at: seq_read_iter+0xe1/0x12d0 fs/seq_file.c:182
 #1: ffff888134629488 (&of->mutex#2){+.+.}-{4:4}, at: kernfs_seq_start+0x4f/0x2a0 fs/kernfs/file.c:172
 #2: ffff8881346c8008 (kn->active#23){++++}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:80 [inline]
 #2: ffff8881346c8008 (kn->active#23){++++}-{0:0}, at: kernfs_seq_start+0xbc/0x2a0 fs/kernfs/file.c:173
 #3: ffff888135067198 (&dev->mutex){....}-{4:4}, at: device_lock_interruptible include/linux/device.h:900 [inline]
 #3: ffff888135067198 (&dev->mutex){....}-{4:4}, at: manufacturer_show+0x26/0xa0 drivers/usb/core/sysfs.c:142
3 locks held by kworker/1:4/7476:
 #0: ffff888100071948 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x128d/0x1b20 kernel/workqueue.c:3232
 #1: ffffc90002197ca0 ((work_completion)(&fw_work->work)){+.+.}-{0:0}, at: process_one_work+0x914/0x1b20 kernel/workqueue.c:3233
 #2: ffff888117455160 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:895 [inline]
 #2: ffff888117455160 (&dev->mutex){....}-{4:4}, at: __device_driver_lock drivers/base/dd.c:1104 [inline]
 #2: ffff888117455160 (&dev->mutex){....}-{4:4}, at: device_release_driver_internal+0xa4/0x620 drivers/base/dd.c:1302
5 locks held by kworker/1:6/7582:
 #0: ffff888105afc148 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work+0x128d/0x1b20 kernel/workqueue.c:3232
 #1: ffffc900023efca0 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work+0x914/0x1b20 kernel/workqueue.c:3233
 #2: ffff88810a78a198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:895 [inline]
 #2: ffff88810a78a198 (&dev->mutex){....}-{4:4}, at: hub_event+0x1be/0x5420 drivers/usb/core/hub.c:5899
 #3: ffff888120618198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:895 [inline]
 #3: ffff888120618198 (&dev->mutex){....}-{4:4}, at: usb_disconnect+0x10a/0x9e0 drivers/usb/core/hub.c:2336
 #4: ffff888117455160
 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:895 [inline]
 (&dev->mutex){....}-{4:4}, at: device_del+0xa0/0x9f0 drivers/base/core.c:3840

=============================================

NMI backtrace for cpu 0
CPU: 0 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:
 <TASK>
 __dump_stack lib/dump_stack.c:94 [inline]
 dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:120
 nmi_cpu_backtrace+0x27b/0x390 lib/nmi_backtrace.c:113
 nmi_trigger_cpumask_backtrace+0x29c/0x300 lib/nmi_backtrace.c:62
 trigger_all_cpu_backtrace include/linux/nmi.h:160 [inline]
 __sys_info lib/sys_info.c:157 [inline]
 sys_info+0x133/0x180 lib/sys_info.c:165
 check_hung_uninterruptible_tasks kernel/hung_task.c:346 [inline]
 watchdog+0xe66/0x1180 kernel/hung_task.c:515
 kthread+0x3c5/0x780 kernel/kthread.c:463
 ret_from_fork+0x74f/0xa30 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246
 </TASK>
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 23 Comm: kworker/1:0 Not tainted syzkaller #0 PREEMPT(voluntary) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
Workqueue: usb_hub_wq hub_event
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:751
Code: 48 89 fa 48 c1 ea 03 80 3c 02 00 75 5c 48 03 1c ed e0 5b e8 88 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:ffffc900001a8ce8 EFLAGS: 00000806
RAX: dffffc0000000000 RBX: ffff8881f5733628 RCX: ffffffff814f59cf
RDX: 0000000000000000 RSI: ffffffff878a7300 RDI: ffffffff88e85be8
RBP: 0000000000000001 R08: 0000000000000000 R09: fffffbfff154921a
R10: ffffffff8aa490d7 R11: ffff888102286268 R12: 0000000000000088
R13: ffff888112475828 R14: ffff8881124757c0 R15: ffff8881f57390c0
FS:  0000000000000000(0000) GS:ffff888268cf4000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000561024603620 CR3: 0000000119ce4000 CR4: 00000000003506f0
Call Trace:
 <IRQ>
 trace_sched_wakeup+0xd2/0x110 include/trace/events/sched.h:178
 ttwu_do_wakeup kernel/sched/core.c:3607 [inline]
 ttwu_do_activate+0x1ac/0x890 kernel/sched/core.c:3634
 ttwu_queue kernel/sched/core.c:3894 [inline]
 try_to_wake_up+0x72d/0x1480 kernel/sched/core.c:4218
 hrtimer_wakeup+0x47/0x60 kernel/time/hrtimer.c:2013
 __run_hrtimer kernel/time/hrtimer.c:1777 [inline]
 __hrtimer_run_queues+0x202/0xc40 kernel/time/hrtimer.c:1841
 hrtimer_interrupt+0x397/0x8e0 kernel/time/hrtimer.c:1903
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1045 [inline]
 __sysvec_apic_timer_interrupt+0x10b/0x3c0 arch/x86/kernel/apic/apic.c:1062
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1056 [inline]
 sysvec_apic_timer_interrupt+0x8b/0xb0 arch/x86/kernel/apic/apic.c:1056
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:console_trylock_spinning kernel/printk/printk.c:2037 [inline]
RIP: 0010:vprintk_emit+0x556/0x6b0 kernel/printk/printk.c:2425
Code: 00 4d 85 ed 0f 85 19 01 00 00 e8 25 1e 21 00 9c 5d 81 e5 00 02 00 00 31 ff 48 89 ee e8 e3 18 21 00 48 85 ed 0f 85 25 01 00 00 <e8> 05 1e 21 00 45 31 c9 41 b8 01 00 00 00 31 c9 48 8d 05 00 00 00
RSP: 0018:ffffc9000018f5a8 EFLAGS: 00000287
RAX: 0000000000027322 RBX: 000000000000003b RCX: ffffc90008630000
RDX: 0000000000100000 RSI: ffffffff815ed285 RDI: 0000000000000007
RBP: 0000000000000000 R08: 0000000000000007 R09: 0000000000000000
R10: 0000000000000000 R11: ffff888102286268 R12: 1ffff92000031eb7
R13: 0000000000000200 R14: ffff8881022e57c0 R15: ffffc9000018f670
 dev_vprintk_emit drivers/base/core.c:4914 [inline]
 dev_printk_emit+0xfa/0x140 drivers/base/core.c:4925
 __dev_printk+0xf5/0x270 drivers/base/core.c:4937
 _dev_info+0xe4/0x120 drivers/base/core.c:4983
 hub_port_init+0xce6/0x3bb0 drivers/usb/core/hub.c:4996
 hub_port_connect drivers/usb/core/hub.c:5496 [inline]
 hub_port_connect_change drivers/usb/core/hub.c:5707 [inline]
 port_event drivers/usb/core/hub.c:5871 [inline]
 hub_event+0x2f75/0x5420 drivers/usb/core/hub.c:5953
 process_one_work+0x9ba/0x1b20 kernel/workqueue.c:3257
 process_scheduled_works kernel/workqueue.c:3340 [inline]
 worker_thread+0x6c8/0xf10 kernel/workqueue.c:3421
 kthread+0x3c5/0x780 kernel/kthread.c:463
 ret_from_fork+0x74f/0xa30 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246
 </TASK>