[syzbot] [libertas?] INFO: task hung in lbs_remove_card

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: 2b38afce25c4 Merge tag 'turbostat-2025.09.09' of git://git..
git tree: https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git usb-testing
console output: https://syzkaller.appspot.com/x/log.txt?x=142f4af0580000
kernel config: https://syzkaller.appspot.com/x/.config?x=fc65f9fdda222232
dashboard link: https://syzkaller.appspot.com/bug?extid=c99d17aa44dbdba16ad2
compiler: gcc (Debian 12.2.0-14+deb12u1) 12.2.0, GNU ld (GNU Binutils for Debian) 2.40

Unfortunately, I don't have any reproducer for this issue yet.

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/03c1659365fe/disk-2b38afce.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/c24a7ba0c087/vmlinux-2b38afce.xz
kernel image: https://storage.googleapis.com/syzbot-assets/ae60f96c7e73/bzImage-2b38afce.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+c99d17...@syzkaller.appspotmail.com

INFO: task kworker/1:5:10878 blocked for more than 143 seconds.
Not tainted 6.16.0-syzkaller-12288-g2b38afce25c4 #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/1:5 state:D
stack:21576 pid:10878 tgid:10878 ppid:2 task_flags:0x4288060 flags:0x00004000
Workqueue: events request_firmware_work_func
Call Trace:
<TASK>
context_switch kernel/sched/core.c:5357 [inline]
__schedule+0x12fc/0x3b90 kernel/sched/core.c:6961
__schedule_loop kernel/sched/core.c:7043 [inline]
schedule+0xe7/0x3a0 kernel/sched/core.c:7058
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:1274 [inline]
device_release_driver_internal+0x44b/0x620 drivers/base/dd.c:1297
usb_driver_release_interface drivers/usb/core/driver.c:640 [inline]
usb_forced_unbind_intf+0x144/0x220 drivers/usb/core/driver.c:1133
usb_reset_device+0x439/0xa90 drivers/usb/core/hub.c:6403
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+0x139/0x250 drivers/base/firmware_loader/main.c:1161
process_one_work+0x9cf/0x1b70 kernel/workqueue.c:3236
process_scheduled_works kernel/workqueue.c:3319 [inline]
worker_thread+0x6c8/0xf10 kernel/workqueue.c:3400
kthread+0x3c5/0x780 kernel/kthread.c:463
ret_from_fork+0x5b6/0x6c0 arch/x86/kernel/process.c:148
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
</TASK>

Showing all locks held in the system:
1 lock held by khungtaskd/30:
#0: ffffffff892c7320 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
#0: ffffffff892c7320 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline]
#0: ffffffff892c7320 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x36/0x1c0 kernel/locking/lockdep.c:6775
2 locks held by getty/2908:
#0: ffff8881123fe0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x24/0x80 drivers/tty/tty_ldisc.c:243
#1: ffffc900000432f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x41b/0x14f0 drivers/tty/n_tty.c:2222
4 locks held by udevd/5192:
3 locks held by kworker/0:4/5233:
3 locks held by kworker/1:5/10878:
#0: ffff888100080d48 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x12a2/0x1b70 kernel/workqueue.c:3211
#1: ffffc90016497d10 ((work_completion)(&fw_work->work)){+.+.}-{0:0}, at: process_one_work+0x929/0x1b70 kernel/workqueue.c:3212
#2: ffff88814573d160 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:911 [inline]
#2: ffff88814573d160 (&dev->mutex){....}-{4:4}, at: __device_driver_lock drivers/base/dd.c:1096 [inline]
#2: ffff88814573d160 (&dev->mutex){....}-{4:4}, at: device_release_driver_internal+0xa4/0x620 drivers/base/dd.c:1294
3 locks held by kworker/1:8/12237:
3 locks held by kworker/0:1/14373:
5 locks held by kworker/0:8/19369:
#0: ffff888106eaf548 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work+0x12a2/0x1b70 kernel/workqueue.c:3211
#1: ffffc90013447d10 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work+0x929/0x1b70 kernel/workqueue.c:3212
#2: ffff88810b752198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:911 [inline]
#2: ffff88810b752198 (&dev->mutex){....}-{4:4}, at: hub_event+0x1be/0x5060 drivers/usb/core/hub.c:5898
#3: ffff88811d13c198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:911 [inline]
#3: ffff88811d13c198 (&dev->mutex){....}-{4:4}, at: usb_disconnect+0x10a/0x9c0 drivers/usb/core/hub.c:2335
#4: ffff88814573d160 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:911 [inline]
#4: ffff88814573d160 (&dev->mutex){....}-{4:4}, at: device_del+0xa0/0x9f0 drivers/base/core.c:3840
2 locks held by kworker/u8:0/21113:
#0: ffff888100089148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work+0x12a2/0x1b70 kernel/workqueue.c:3211
#1: ffffc90012d3fd10 ((reaper_work).work){+.+.}-{0:0}, at: process_one_work+0x929/0x1b70 kernel/workqueue.c:3212
4 locks held by kworker/1:7/23200:

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

NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 30 Comm: khungtaskd Not tainted 6.16.0-syzkaller-12288-g2b38afce25c4 #0 PREEMPT(voluntary)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
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]
check_hung_uninterruptible_tasks kernel/hung_task.c:328 [inline]
watchdog+0xf0e/0x1260 kernel/hung_task.c:491
kthread+0x3c5/0x780 kernel/kthread.c:463
ret_from_fork+0x5b6/0x6c0 arch/x86/kernel/process.c:148
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
</TASK>
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 5219 Comm: kworker/1:4 Not tainted 6.16.0-syzkaller-12288-g2b38afce25c4 #0 PREEMPT(voluntary)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
Workqueue: events legacy_dvb_usb_read_remote_control
RIP: 0010:io_serial_out+0x8f/0xb0 drivers/tty/serial/8250/8250_port.c:407
Code: 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 1c 66 03 5d 40 44 89 e8 89 da ee <5b> 5d 41 5c 41 5d e9 06 6b 66 04 e8 41 85 02 ff eb a0 e8 ca 85 02
RSP: 0018:ffffc9000233f700 EFLAGS: 00000006
RAX: 0000000000000000 RBX: 00000000000003f9 RCX: 0000000000000000
RDX: 00000000000003f9 RSI: ffffffff82d9a765 RDI: ffffffff93b7f160
RBP: ffffffff93b7f120 R08: 0000000000000001 R09: 000000000000001f
R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000
R13: 0000000000000000 R14: ffffffff93b7f120 R15: ffffffff93b7f3e0
FS: 0000000000000000(0000) GS:ffff888268ffc000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00005555908fc4a8 CR3: 000000014b144000 CR4: 00000000003506f0
Call Trace:
<TASK>
serial_out drivers/tty/serial/8250/8250.h:142 [inline]
serial8250_clear_IER+0x9b/0xc0 drivers/tty/serial/8250/8250_port.c:713
serial8250_console_write+0x255/0x1890 drivers/tty/serial/8250/8250_port.c:3361
console_emit_next_record kernel/printk/printk.c:3138 [inline]
console_flush_all+0x7fe/0xc60 kernel/printk/printk.c:3226
__console_flush_and_unlock kernel/printk/printk.c:3285 [inline]
console_unlock+0xd8/0x210 kernel/printk/printk.c:3325
vprintk_emit+0x418/0x6d0 kernel/printk/printk.c:2450
_printk+0xc7/0x100 kernel/printk/printk.c:2475
legacy_dvb_usb_read_remote_control+0x40b/0x4f0 drivers/media/usb/dvb-usb/dvb-usb-remote.c:124
process_one_work+0x9cf/0x1b70 kernel/workqueue.c:3236
process_scheduled_works kernel/workqueue.c:3319 [inline]
worker_thread+0x6c8/0xf10 kernel/workqueue.c:3400
kthread+0x3c5/0x780 kernel/kthread.c:463
ret_from_fork+0x5b6/0x6c0 arch/x86/kernel/process.c:148
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
</TASK>


---
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If the report is a duplicate of another one, reply with:
#syz dup: exact-subject-of-another-report

If you want to undo deduplication, reply with:
#syz undup

[syzbot]

syzbot has found a reproducer for the following issue on:

HEAD commit: bb375c251ab4 dt-bindings: usb: st,st-ohci-300x: convert to..

git tree: https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git usb-testing

console output: https://syzkaller.appspot.com/x/log.txt?x=1141755a580000
kernel config: https://syzkaller.appspot.com/x/.config?x=f1500201919951cc
dashboard link: https://syzkaller.appspot.com/bug?extid=c99d17aa44dbdba16ad2
compiler: gcc (Debian 14.2.0-19) 14.2.0, GNU ld (GNU Binutils for Debian) 2.44
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=1191555a580000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=114a15c6580000

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/2475c3172471/disk-bb375c25.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/30449aa672dd/vmlinux-bb375c25.xz
kernel image: https://storage.googleapis.com/syzbot-assets/46d3937d1c16/bzImage-bb375c25.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+c99d17...@syzkaller.appspotmail.com

INFO: task kworker/0:1:10 blocked for more than 143 seconds.
Not tainted syzkaller #0

"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.

task:kworker/0:1 state:D stack:26840 pid:10 tgid:10 ppid:2 task_flags:0x4288060 flags:0x00080000
Workqueue: usb_hub_wq hub_event
Call Trace:
<TASK>
context_switch kernel/sched/core.c:5295 [inline]
__schedule+0xeb1/0x41f0 kernel/sched/core.c:6907
__schedule_loop kernel/sched/core.c:6989 [inline]
schedule+0xdd/0x390 kernel/sched/core.c:7004

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:573 [inline]
device_remove+0x12a/0x180 drivers/base/dd.c:565
__device_release_driver drivers/base/dd.c:1284 [inline]
device_release_driver_internal+0x42e/0x600 drivers/base/dd.c:1307
bus_remove_device+0x22f/0x440 drivers/base/bus.c:616
device_del+0x376/0x9b0 drivers/base/core.c:3878
usb_disable_device+0x367/0x810 drivers/usb/core/message.c:1418
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+0x9d7/0x1920 kernel/workqueue.c:3275
process_scheduled_works kernel/workqueue.c:3358 [inline]
worker_thread+0x5da/0xe40 kernel/workqueue.c:3439
kthread+0x370/0x450 kernel/kthread.c:467
ret_from_fork+0x6c3/0xcb0 arch/x86/kernel/process.c:158

ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
</TASK>

Showing all locks held in the system:

5 locks held by kworker/0:1/10:
#0: ffff8881056afd48 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work+0x1287/0x1920 kernel/workqueue.c:3250
#1: ffffc900000afd18 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work+0x93c/0x1920 kernel/workqueue.c:3251
#2: ffff88810b795198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:895 [inline]
#2: ffff88810b795198 (&dev->mutex){....}-{4:4}, at: hub_event+0x1bd/0x4af0 drivers/usb/core/hub.c:5899
#3: ffff88811c2c3198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:895 [inline]
#3: ffff88811c2c3198 (&dev->mutex){....}-{4:4}, at: usb_disconnect+0x10a/0x9a0 drivers/usb/core/hub.c:2336
#4: ffff88811bcbf160 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:895 [inline]
#4: ffff88811bcbf160 (&dev->mutex){....}-{4:4}, at: __device_driver_lock drivers/base/dd.c:1106 [inline]
#4: ffff88811bcbf160 (&dev->mutex){....}-{4:4}, at: device_release_driver_internal+0xaa/0x600 drivers/base/dd.c:1304
2 locks held by kworker/1:0/23:
#0: ffff88810006b548 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x1287/0x1920 kernel/workqueue.c:3250
#1: ffffc9000018fd18 ((work_completion)(&fw_work->work)){+.+.}-{0:0}, at: process_one_work+0x93c/0x1920 kernel/workqueue.c:3251

1 lock held by khungtaskd/30:

#0: ffffffff896e05a0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:312 [inline]
#0: ffffffff896e05a0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:850 [inline]
#0: ffffffff896e05a0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x3d/0x184 kernel/locking/lockdep.c:6775
2 locks held by getty/2917:
#0: ffff888115dd90a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x24/0x80 drivers/tty/tty_ldisc.c:243
#1: ffffc900000432f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x419/0x1500 drivers/tty/n_tty.c:2211

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

NMI backtrace for cpu 0

CPU: 0 UID: 0 PID: 30 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026

Call Trace:
<TASK>
__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+0xd25/0x1050 kernel/hung_task.c:515
kthread+0x370/0x450 kernel/kthread.c:467
ret_from_fork+0x6c3/0xcb0 arch/x86/kernel/process.c:158

ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
</TASK>
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1

CPU: 1 UID: 0 PID: 0 Comm: swapper/1 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
RIP: 0010:pv_native_safe_halt+0xf/0x20 arch/x86/kernel/paravirt.c:63
Code: ae b1 01 e9 13 e8 02 00 0f 1f 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 66 90 0f 00 2d d3 e1 1d 00 fb f4 <c3> cc cc cc cc 66 2e 0f 1f 84 00 00 00 00 00 66 90 90 90 90 90 90
RSP: 0018:ffffc9000013fe00 EFLAGS: 00000242
RAX: 000000000007f00b RBX: ffff8881022a1d00 RCX: ffffffff876898d5
RDX: 0000000000000000 RSI: ffffffff8901db96 RDI: ffffffff87afa420
RBP: 0000000000000001 R08: 0000000000000001 R09: ffffed103eae6725
R10: ffff8881f573392b R11: 0000000000000000 R12: ffffed10204543a0
R13: 0000000000000001 R14: ffffffff8aefe2d0 R15: 0000000000000000
FS: 0000000000000000(0000) GS:ffff8882687d3000(0000) knlGS:0000000000000000

CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033

CR2: 00007f983bef5900 CR3: 0000000116d22000 CR4: 00000000003506f0
Call Trace:
<TASK>
arch_safe_halt arch/x86/include/asm/paravirt.h:73 [inline]
default_idle+0x9/0x10 arch/x86/kernel/process.c:767
default_idle_call+0x6c/0xb0 kernel/sched/idle.c:122
cpuidle_idle_call kernel/sched/idle.c:191 [inline]
do_idle+0x35b/0x4b0 kernel/sched/idle.c:332
cpu_startup_entry+0x4f/0x60 kernel/sched/idle.c:430
start_secondary+0x21d/0x2d0 arch/x86/kernel/smpboot.c:312
common_startup_64+0x13e/0x148
</TASK>


---
If you want syzbot to run the reproducer, reply with:
#syz test: git://repo/address.git branch-or-commit-hash
If you attach or paste a git patch, syzbot will apply it before testing.

[Hillf Danton]

> Date: Fri, 27 Feb 2026 03:22:26 -0800 [thread overview]

> syzbot has found a reproducer for the following issue on:
>
> HEAD commit: bb375c251ab4 dt-bindings: usb: st,st-ohci-300x: convert to..
> git tree: https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git usb-testing
> console output: https://syzkaller.appspot.com/x/log.txt?x=1141755a580000
> kernel config: https://syzkaller.appspot.com/x/.config?x=f1500201919951cc
> dashboard link: https://syzkaller.appspot.com/bug?extid=c99d17aa44dbdba16ad2
> compiler: gcc (Debian 14.2.0-19) 14.2.0, GNU ld (GNU Binutils for Debian) 2.44
> syz repro: https://syzkaller.appspot.com/x/repro.syz?x=1191555a580000
> C reproducer: https://syzkaller.appspot.com/x/repro.c?x=114a15c6580000

#syz test

--- x/drivers/net/wireless/marvell/libertas/firmware.c
+++ y/drivers/net/wireless/marvell/libertas/firmware.c
@@ -111,9 +111,20 @@ next:
do_load_firmware(priv, iter->helper, helper_firmware_cb);
}

+static bool lbs_check_fw_loaded(struct lbs_private *priv)
+{
+ unsigned long flags;
+ bool rc;
+
+ spin_lock_irqsave(&priv->driver_lock, flags);
+ rc = priv->fw_callback == NULL;
+ spin_unlock_irqrestore(&priv->driver_lock, flags);
+ return rc;
+}
+
void lbs_wait_for_firmware_load(struct lbs_private *priv)
{
- wait_event(priv->fw_waitq, priv->fw_callback == NULL);
+ wait_event(priv->fw_waitq, true == lbs_check_fw_loaded(priv));
}

/**
--

[syzbot]

Hello,

syzbot has tested the proposed patch but the reproducer is still triggering an issue:
INFO: task hung in lbs_remove_card

INFO: task kworker/1:2:705 blocked for more than 143 seconds.

Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.

task:kworker/1:2 state:D stack:26328 pid:705 tgid:705 ppid:2 task_flags:0x4288060 flags:0x00080000

Workqueue: usb_hub_wq hub_event
Call Trace:
<TASK>
context_switch kernel/sched/core.c:5295 [inline]
__schedule+0xeb1/0x41f0 kernel/sched/core.c:6907
__schedule_loop kernel/sched/core.c:6989 [inline]
schedule+0xdd/0x390 kernel/sched/core.c:7004

lbs_wait_for_firmware_load+0x190/0x260 drivers/net/wireless/marvell/libertas/firmware.c:127

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:573 [inline]
device_remove+0x12a/0x180 drivers/base/dd.c:565
__device_release_driver drivers/base/dd.c:1284 [inline]
device_release_driver_internal+0x42e/0x600 drivers/base/dd.c:1307
bus_remove_device+0x22f/0x440 drivers/base/bus.c:616
device_del+0x376/0x9b0 drivers/base/core.c:3878
usb_disable_device+0x367/0x810 drivers/usb/core/message.c:1418
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+0x9d7/0x1920 kernel/workqueue.c:3275
process_scheduled_works kernel/workqueue.c:3358 [inline]
worker_thread+0x5da/0xe40 kernel/workqueue.c:3439
kthread+0x370/0x450 kernel/kthread.c:467
ret_from_fork+0x6c3/0xcb0 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
</TASK>

Showing all locks held in the system:

2 locks held by kworker/0:1/10:

#0: ffff88810006b548 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x1287/0x1920 kernel/workqueue.c:3250

#1: ffffc900000afd18 ((work_completion)(&fw_work->work)){+.+.}-{0:0}, at: process_one_work+0x93c/0x1920 kernel/workqueue.c:3251

1 lock held by khungtaskd/30:
#0: ffffffff896e05a0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:312 [inline]
#0: ffffffff896e05a0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:850 [inline]
#0: ffffffff896e05a0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x3d/0x184 kernel/locking/lockdep.c:6775

5 locks held by kworker/1:2/705:
#0: ffff888105eac148 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work+0x1287/0x1920 kernel/workqueue.c:3250
#1: ffffc90001fbfd18 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work+0x93c/0x1920 kernel/workqueue.c:3251
#2: ffff88810b76a198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:895 [inline]
#2: ffff88810b76a198 (&dev->mutex){....}-{4:4}, at: hub_event+0x1bd/0x4af0 drivers/usb/core/hub.c:5899
#3: ffff888106382198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:895 [inline]
#3: ffff888106382198 (&dev->mutex){....}-{4:4}, at: usb_disconnect+0x10a/0x9a0 drivers/usb/core/hub.c:2336
#4: ffff888115d0a160 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:895 [inline]
#4: ffff888115d0a160 (&dev->mutex){....}-{4:4}, at: __device_driver_lock drivers/base/dd.c:1106 [inline]
#4: ffff888115d0a160 (&dev->mutex){....}-{4:4}, at: device_release_driver_internal+0xaa/0x600 drivers/base/dd.c:1304
2 locks held by getty/2917:
#0: ffff888115b8b0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x24/0x80 drivers/tty/tty_ldisc.c:243

#1: ffffc900000432f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x419/0x1500 drivers/tty/n_tty.c:2211

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

NMI backtrace for cpu 1

CPU: 1 UID: 0 PID: 30 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT(full)

Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
Call Trace:
<TASK>
__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+0xd25/0x1050 kernel/hung_task.c:515
kthread+0x370/0x450 kernel/kthread.c:467
ret_from_fork+0x6c3/0xcb0 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
</TASK>

Sending NMI from CPU 1 to CPUs 0:

NMI backtrace for cpu 0

CPU: 0 UID: 0 PID: 0 Comm: swapper/0 Not tainted syzkaller #0 PREEMPT(full)

Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
RIP: 0010:pv_native_safe_halt+0xf/0x20 arch/x86/kernel/paravirt.c:63
Code: ae b1 01 e9 13 e8 02 00 0f 1f 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 66 90 0f 00 2d d3 e1 1d 00 fb f4 <c3> cc cc cc cc 66 2e 0f 1f 84 00 00 00 00 00 66 90 90 90 90 90 90

RSP: 0018:ffffffff89407e10 EFLAGS: 00000242
RAX: 00000000000f7031 RBX: ffffffff8942ea40 RCX: ffffffff876898d5

RDX: 0000000000000000 RSI: ffffffff8901db96 RDI: ffffffff87afa420

RBP: 0000000000000000 R08: 0000000000000001 R09: ffffed103eac6725
R10: ffff8881f563392b R11: 0000000000000000 R12: fffffbfff1285d48
R13: 0000000000000000 R14: ffffffff8aefe2d0 R15: 0000000000000000
FS: 0000000000000000(0000) GS:ffff8882686d3000(0000) knlGS:0000000000000000

CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033

CR2: 00007fe3889f5900 CR3: 00000001323d4000 CR4: 00000000003506f0

Call Trace:
<TASK>
arch_safe_halt arch/x86/include/asm/paravirt.h:73 [inline]
default_idle+0x9/0x10 arch/x86/kernel/process.c:767
default_idle_call+0x6c/0xb0 kernel/sched/idle.c:122
cpuidle_idle_call kernel/sched/idle.c:191 [inline]
do_idle+0x35b/0x4b0 kernel/sched/idle.c:332
cpu_startup_entry+0x4f/0x60 kernel/sched/idle.c:430

rest_init+0x251/0x260 init/main.c:760
start_kernel+0x47a/0x480 init/main.c:1210
x86_64_start_reservations+0x24/0x30 arch/x86/kernel/head64.c:310
x86_64_start_kernel+0x12b/0x130 arch/x86/kernel/head64.c:291
common_startup_64+0x13e/0x148
</TASK>


Tested on:

commit: bb375c25 dt-bindings: usb: st,st-ohci-300x: convert to..

git tree: https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git usb-testing

console output: https://syzkaller.appspot.com/x/log.txt?x=1168d55a580000

kernel config: https://syzkaller.appspot.com/x/.config?x=f1500201919951cc
dashboard link: https://syzkaller.appspot.com/bug?extid=c99d17aa44dbdba16ad2
compiler: gcc (Debian 14.2.0-19) 14.2.0, GNU ld (GNU Binutils for Debian) 2.44

patch: https://syzkaller.appspot.com/x/patch.diff?x=10122202580000