BUG: workqueue lockup - pool cpus=1 node=0 flags=0x0 nice=0 stuck for 144s!
Showing busy workqueues and worker pools:
workqueue events: flags=0x100
pwq 2: cpus=0 node=0 flags=0x0 nice=0 active=1 refcnt=2
pending: kernfs_notify_workfn
pwq 6: cpus=1 node=0 flags=0x0 nice=0 active=2 refcnt=3
pending: legacy_dvb_usb_read_remote_control, free_obj_work
workqueue events_power_efficient: flags=0x180
pwq 6: cpus=1 node=0 flags=0x0 nice=0 active=7 refcnt=8
pending: neigh_managed_work, neigh_periodic_work, gc_worker, 4*check_lifetime
workqueue mm_percpu_wq: flags=0x8
pwq 6: cpus=1 node=0 flags=0x0 nice=0 active=1 refcnt=2
pending: vmstat_update
workqueue kblockd: flags=0x18
pwq 7: cpus=1 node=0 flags=0x0 nice=-20 active=2 refcnt=3
pending: blk_mq_requeue_work, blk_mq_timeout_work
workqueue usb_hub_wq: flags=0x104
pwq 2: cpus=0 node=0 flags=0x0 nice=0 active=4 refcnt=5
in-flight: 5233:hub_event hub_event ,5280:hub_event hub_event
pwq 6: cpus=1 node=0 flags=0x0 nice=0 active=4 refcnt=5
in-flight: 5321:hub_event hub_event ,5247:hub_event hub_event
pool 2: cpus=0 node=0 flags=0x0 nice=0 hung=0s workers=8 idle: 1122 5234 9 5567 10 10629
pool 6: cpus=1 node=0 flags=0x0 nice=0 hung=144s workers=7 idle: 38 2519 23 7892 5238
Showing backtraces of running workers in stalled CPU-bound worker pools:
pool 6:
task:kworker/1:5 state:R running task stack:21144 pid:5321 tgid:5321 ppid:2 task_flags:0x4208060 flags:0x00080010
Workqueue: usb_hub_wq hub_event
Call Trace:
pool 6:
task:kworker/1:4 state:R running task stack:21416 pid:5247 tgid:5247 ppid:2 task_flags:0x4208060 flags:0x00080000
Workqueue: usb_hub_wq hub_event
Call Trace:
context_switch kernel/sched/core.c:5260 [inline]
__schedule+0xeb0/0x3e50 kernel/sched/core.c:6867
__schedule_loop kernel/sched/core.c:6949 [inline]
schedule+0xdd/0x390 kernel/sched/core.c:6964
schedule_timeout+0x127/0x280 kernel/time/sleep_timeout.c:99
do_wait_for_common kernel/sched/completion.c:100 [inline]
__wait_for_common+0x2e7/0x4c0 kernel/sched/completion.c:121
usb_start_wait_urb+0x147/0x4c0 drivers/usb/core/message.c:64
usb_internal_control_msg drivers/usb/core/message.c:103 [inline]
usb_control_msg+0x326/0x4a0 drivers/usb/core/message.c:154
reg_w.part.0+0x86/0xf0 drivers/media/usb/gspca/zc3xx.c:5559
reg_w drivers/media/usb/gspca/zc3xx.c:5557 [inline]
start_2wr_probe+0x67/0x1f0 drivers/media/usb/gspca/zc3xx.c:6037
vga_2wr_probe drivers/media/usb/gspca/zc3xx.c:6066 [inline]
zcxx_probeSensor drivers/media/usb/gspca/zc3xx.c:6311 [inline]
zcxx_probeSensor+0x8e/0x2ae0 drivers/media/usb/gspca/zc3xx.c:6294
sd_init+0x22/0x1590 drivers/media/usb/gspca/zc3xx.c:6507
gspca_dev_probe2+0xad0/0x1636 drivers/media/usb/gspca/gspca.c:1532
gspca_dev_probe.cold+0x1a/0xb9 drivers/media/usb/gspca/gspca.c:1608
usb_probe_interface+0x303/0x8f0 drivers/usb/core/driver.c:396
call_driver_probe drivers/base/dd.c:581 [inline]
really_probe+0x241/0xa60 drivers/base/dd.c:659
__driver_probe_device+0x1de/0x400 drivers/base/dd.c:801
driver_probe_device+0x4c/0x1b0 drivers/base/dd.c:831
__device_attach_driver+0x1df/0x340 drivers/base/dd.c:959
bus_for_each_drv+0x159/0x1e0 drivers/base/bus.c:500
__device_attach+0x1e4/0x4d0 drivers/base/dd.c:1031
device_initial_probe+0xaf/0xd0 drivers/base/dd.c:1086
bus_probe_device+0x64/0x160 drivers/base/bus.c:574
device_add+0x11d9/0x1950 drivers/base/core.c:3689
usb_set_configuration+0xd97/0x1c60 drivers/usb/core/message.c:2210
usb_generic_driver_probe+0xa1/0xe0 drivers/usb/core/generic.c:250
usb_probe_device+0xef/0x400 drivers/usb/core/driver.c:291
call_driver_probe drivers/base/dd.c:581 [inline]
really_probe+0x241/0xa60 drivers/base/dd.c:659
__driver_probe_device+0x1de/0x400 drivers/base/dd.c:801
driver_probe_device+0x4c/0x1b0 drivers/base/dd.c:831
__device_attach_driver+0x1df/0x340 drivers/base/dd.c:959
bus_for_each_drv+0x159/0x1e0 drivers/base/bus.c:500
__device_attach+0x1e4/0x4d0 drivers/base/dd.c:1031
device_initial_probe+0xaf/0xd0 drivers/base/dd.c:1086
bus_probe_device+0x64/0x160 drivers/base/bus.c:574
device_add+0x11d9/0x1950 drivers/base/core.c:3689
usb_new_device.cold+0x685/0x115c drivers/usb/core/hub.c:2695
hub_port_connect drivers/usb/core/hub.c:5567 [inline]
hub_port_connect_change drivers/usb/core/hub.c:5707 [inline]
port_event drivers/usb/core/hub.c:5871 [inline]
hub_event+0x314d/0x4af0 drivers/usb/core/hub.c:5953
process_one_work+0x9c2/0x1840 kernel/workqueue.c:3257
process_scheduled_works kernel/workqueue.c:3340 [inline]
worker_thread+0x5da/0xe40 kernel/workqueue.c:3421
kthread+0x3b3/0x730 kernel/kthread.c:463
ret_from_fork+0x6c3/0xa20 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 1122 Comm: kworker/0:2 Not tainted syzkaller #0 PREEMPT(voluntary)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
Workqueue: events legacy_dvb_usb_read_remote_control
RIP: 0010:rcu_is_watching+0x80/0xc0 kernel/rcu/tree.c:752
Code: 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 83 e0 01 65 ff 0d 00 af 34 0b <74> 07 5b 5d c3 cc cc cc cc 0f 1f 44 00 00 5b 5d e9 9b b8 bf 05 48
RSP: 0018:ffffc90000007e38 EFLAGS: 00000082
RAX: 0000000000000001 RBX: ffff8881f5633628 RCX: 0000000000000002
RDX: 0000000000000000 RSI: ffffffff878e9720 RDI: ffffffff88f6cbe0
RBP: 0000000000000000 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000001 R12: 0000000000000002
R13: 0000000000000001 R14: 0000000000000000 R15: 0000000000000000
FS: 0000000000000000(0000) GS:ffff88826896a000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000000 CR3: 0000000112740000 CR4: 00000000003506f0
Call Trace:
trace_lock_acquire include/trace/events/lock.h:24 [inline]
lock_acquire+0x2c4/0x330 kernel/locking/lockdep.c:5831
seqcount_lockdep_reader_access include/linux/seqlock.h:72 [inline]
ktime_get_update_offsets_now+0x8f/0x4d0 kernel/time/timekeeping.c:2570
hrtimer_update_base kernel/time/hrtimer.c:633 [inline]
hrtimer_interrupt+0x13e/0x8c0 kernel/time/hrtimer.c:1885
local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1045 [inline]
__sysvec_apic_timer_interrupt+0x109/0x3c0 arch/x86/kernel/apic/apic.c:1062
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1056 [inline]
sysvec_apic_timer_interrupt+0x8a/0xb0 arch/x86/kernel/apic/apic.c:1056
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+0x553/0x6b0 kernel/printk/printk.c:2425
Code: 00 4d 85 ed 0f 85 1b 01 00 00 e8 78 54 20 00 9c 5d 81 e5 00 02 00 00 31 ff 48 89 ee e8 46 4f 20 00 48 85 ed 0f 85 27 01 00 00 58 54 20 00 45 31 c9 41 b8 01 00 00 00 31 c9 48 8d 05 00 00 00
RSP: 0018:ffffc90001c1f970 EFLAGS: 00000293
RAX: 0000000000000000 RBX: 0000000000000017 RCX: ffffffff8190e8ba
RDX: ffff88810eb657c0 RSI: ffffffff8190e8c4 RDI: ffff88810eb657c0
RBP: 0000000000000000 R08: 0000000000000007 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: 1ffff92000383f30
R13: 0000000000000200 R14: ffff888115428000 R15: ffffc90001c1fa38
_printk+0xcf/0x110 kernel/printk/printk.c:2451
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+0x9c2/0x1840 kernel/workqueue.c:3257
process_scheduled_works kernel/workqueue.c:3340 [inline]
worker_thread+0x5da/0xe40 kernel/workqueue.c:3421
kthread+0x3b3/0x730 kernel/kthread.c:463
ret_from_fork+0x6c3/0xa20 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246
----------------
Code disassembly (best guess):
0: 89 da mov %ebx,%edx
2: 48 c1 ea 03 shr $0x3,%rdx
6: 0f b6 14 02 movzbl (%rdx,%rax,1),%edx
a: 48 89 d8 mov %rbx,%rax
d: 83 e0 07 and $0x7,%eax
10: 83 c0 03 add $0x3,%eax
13: 38 d0 cmp %dl,%al
15: 7c 04 jl 0x1b
17: 84 d2 test %dl,%dl
19: 75 24 jne 0x3f
1b: 8b 03 mov (%rbx),%eax
1d: c1 e8 02 shr $0x2,%eax
20: 83 e0 01 and $0x1,%eax
23: 65 ff 0d 00 af 34 0b decl %gs:0xb34af00(%rip) # 0xb34af2a
* 2a: 74 07 je 0x33 <-- trapping instruction
2c: 5b pop %rbx
2d: 5d pop %rbp
2e: c3 ret
2f: cc int3
30: cc int3
31: cc int3
32: cc int3
33: 0f 1f 44 00 00 nopl 0x0(%rax,%rax,1)
38: 5b pop %rbx
39: 5d pop %rbp
3a: e9 9b b8 bf 05 jmp 0x5bfb8da
3f: 48 rex.W