syzbot
INFO: task hung in ath9k_hif_usb_firmware_cb (5)
Status:
upstream: reported on 2026/10/18 15:27
Reported-by: syzbot+a42c4238d6a925993d6e@syzkaller.appspotmail.com
First crash: 1d21h, last: 1d21h
Sample crash report:
INFO: task kworker/0:4:4260 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:19808 pid: 4260 ppid: 2 flags:0x00004000
Workqueue: events request_firmware_work_func
Call Trace:
<TASK>
context_switch kernel/sched/core.c:5049 [inline]
__schedule+0x11c3/0x4350 kernel/sched/core.c:6395
schedule+0x11b/0x1e0 kernel/sched/core.c:6478
schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:6537
__mutex_lock_common+0xdf5/0x2400 kernel/locking/mutex.c:669
__mutex_lock kernel/locking/mutex.c:729 [inline]
mutex_lock_nested+0x17/0x20 kernel/locking/mutex.c:743
device_lock include/linux/device.h:809 [inline]
ath9k_hif_usb_firmware_fail drivers/net/wireless/ath/ath9k/hif_usb.c:1163 [inline]
ath9k_hif_usb_firmware_cb+0x326/0x4b0 drivers/net/wireless/ath/ath9k/hif_usb.c:1291
request_firmware_work_func+0xe8/0x1a0 drivers/base/firmware_loader/main.c:1129
process_one_work+0x867/0xff0 kernel/workqueue.c:2310
worker_thread+0xad7/0x12a0 kernel/workqueue.c:2457
kthread+0x42e/0x520 kernel/kthread.c:334
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287
</TASK>
Showing all locks held in the system:
1 lock held by khungtaskd/27:
#0: ffffffff8d11efa0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x0/0x30
4 locks held by udevd/4176:
#0: ffff888018fb1418 (&p->lock){+.+.}-{3:3}, at: seq_read_iter+0x9d/0xc50 fs/seq_file.c:182
#1: ffff88805f571488 (&of->mutex){+.+.}-{3:3}, at: kernfs_seq_start+0x55/0x3c0 fs/kernfs/file.c:112
#2: ffff888026bc8ae8 (kn->active#32){++++}-{0:0}, at: kernfs_seq_start+0x75/0x3c0 fs/kernfs/file.c:113
#3: ffff8880797491a8 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:809 [inline]
#3: ffff8880797491a8 (&dev->mutex){....}-{3:3}, at: uevent_show+0x16c/0x320 drivers/base/core.c:2408
3 locks held by kworker/0:4/4260:
#0: ffff888017870938 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x75c/0xff0 kernel/workqueue.c:-1
#1: ffffc900034dfd00 ((work_completion)(&fw_work->work)){+.+.}-{0:0}, at: process_one_work+0x79e/0xff0 kernel/workqueue.c:2285
#2: ffff888025078220 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:809 [inline]
#2: ffff888025078220 (&dev->mutex){....}-{3:3}, at: ath9k_hif_usb_firmware_fail drivers/net/wireless/ath/ath9k/hif_usb.c:1163 [inline]
#2: ffff888025078220 (&dev->mutex){....}-{3:3}, at: ath9k_hif_usb_firmware_cb+0x326/0x4b0 drivers/net/wireless/ath/ath9k/hif_usb.c:1291
3 locks held by kworker/1:3/4263:
#0: ffff888017870938 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x75c/0xff0 kernel/workqueue.c:-1
#1: ffffc900034ffd00 (key_gc_work){+.+.}-{0:0}, at: process_one_work+0x79e/0xff0 kernel/workqueue.c:2285
#2: ffffffff8d123a28 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:290 [inline]
#2: ffffffff8d123a28 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x2d1/0x750 kernel/rcu/tree_exp.h:845
5 locks held by kworker/0:13/4395:
#0: ffff88801c902938 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work+0x75c/0xff0 kernel/workqueue.c:-1
#1: ffffc900032cfd00 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work+0x79e/0xff0 kernel/workqueue.c:2285
#2: ffff888025078220 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:809 [inline]
#2: ffff888025078220 (&dev->mutex){....}-{3:3}, at: hub_event+0x178/0x5260 drivers/usb/core/hub.c:5832
#3: ffff888079748220 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:809 [inline]
#3: ffff888079748220 (&dev->mutex){....}-{3:3}, at: __device_attach+0x85/0x480 drivers/base/dd.c:974
#4: ffff8880797491a8 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:809 [inline]
#4: ffff8880797491a8 (&dev->mutex){....}-{3:3}, at: __device_attach+0x85/0x480 drivers/base/dd.c:974
2 locks held by kworker/1:12/4634:
#0: ffff888017872138 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_one_work+0x75c/0xff0 kernel/workqueue.c:-1
#1: ffffc9000326fd00 ((work_completion)(&rew.rew_work)){+.+.}-{0:0}, at: process_one_work+0x79e/0xff0 kernel/workqueue.c:2285
1 lock held by syz.3.439/6305:
=============================================
NMI backtrace for cpu 1
CPU: 1 PID: 27 Comm: khungtaskd Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
Call Trace:
<TASK>
dump_stack_lvl+0x188/0x250 lib/dump_stack.c:106
nmi_cpu_backtrace+0x3a2/0x3d0 lib/nmi_backtrace.c:111
nmi_trigger_cpumask_backtrace+0x163/0x280 lib/nmi_backtrace.c:62
trigger_all_cpu_backtrace include/linux/nmi.h:148 [inline]
check_hung_uninterruptible_tasks kernel/hung_task.c:212 [inline]
watchdog+0xe1b/0xe60 kernel/hung_task.c:369
kthread+0x42e/0x520 kernel/kthread.c:334
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287
</TASK>
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 4445 Comm: kworker/u4:7 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
Workqueue: bat_events batadv_nc_worker
RIP: 0010:kasan_check_range+0x1b0/0x290 mm/kasan/generic.c:-1
Code: f3 4d 01 f3 49 89 df 49 8d 5f 07 4d 85 ff 49 0f 49 df 48 83 e3 f8 49 29 df 74 0e 41 80 3b 00 75 69 49 ff c3 49 ff cf 75 f2 5b <41> 5c 41 5e 41 5f 5d c3 45 84 ff 0f 85 91 00 00 00 41 f7 c7 00 ff
RSP: 0018:ffffc9000332f758 EFLAGS: 00000056
RAX: 0000000000000001 RBX: 0000000000000000 RCX: ffffffff815cfde1
RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffffffff910151b0
RBP: ffffc9000332f9c8 R08: ffffffff910151b7 R09: 1ffffffff2202a36
R10: dffffc0000000000 R11: fffffbfff2202a37 R12: dffffc0000000001
R13: ffff88801ea78004 R14: 1ffffffff2202a36 R15: 0000000000000001
FS: 0000000000000000(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000200000ffa030 CR3: 0000000060935000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
<TASK>
instrument_atomic_read include/linux/instrumented.h:71 [inline]
test_bit include/asm-generic/bitops/instrumented-non-atomic.h:134 [inline]
hlock_class kernel/locking/lockdep.c:197 [inline]
check_wait_context kernel/locking/lockdep.c:4784 [inline]
__lock_acquire+0xa41/0x7d40 kernel/locking/lockdep.c:5070
lock_acquire+0x19f/0x400 kernel/locking/lockdep.c:5737
__raw_spin_lock_bh include/linux/spinlock_api_smp.h:135 [inline]
_raw_spin_lock_bh+0x32/0x50 kernel/locking/spinlock.c:178
spin_lock_bh include/linux/spinlock.h:369 [inline]
batadv_nc_purge_paths+0xe2/0x3a0 net/batman-adv/network-coding.c:446
batadv_nc_worker+0x2e1/0x5c0 net/batman-adv/network-coding.c:724
process_one_work+0x867/0xff0 kernel/workqueue.c:2310
worker_thread+0xad7/0x12a0 kernel/workqueue.c:2457
kthread+0x42e/0x520 kernel/kthread.c:334
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287
</TASK>
* Struck through repros no longer work on HEAD.