rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: (detected by 0, t=10502 jiffies, g=226957, q=321 ncpus=2)
rcu: All QSes seen, last rcu_preempt kthread activity 10498 (4295106245-4295095747), jiffies_till_next_fqs=1, root ->qsmask 0x0
rcu: rcu_preempt kthread starved for 10498 jiffies! g226957 f0x2 RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=0
rcu: Unless rcu_preempt kthread gets sufficient CPU time, OOM is now expected behavior.
rcu: RCU grace-period kthread stack dump:
task:rcu_preempt state:R running task
stack:28488 pid:15 tgid:15 ppid:2 task_flags:0x208040 flags:0x00080000
Call Trace:
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
schedule_timeout+0x123/0x290 kernel/time/sleep_timeout.c:99
rcu_gp_fqs_loop+0x1ea/0xaf0 kernel/rcu/tree.c:2083
rcu_gp_kthread+0x26d/0x380 kernel/rcu/tree.c:2285
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
rcu: Stack dump where RCU GP kthread last ran:
CPU: 0 UID: 0 PID: 14234 Comm: kworker/0:13 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:__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:152 [inline]
RIP: 0010:_raw_spin_unlock_irqrestore+0x31/0x80 kernel/locking/spinlock.c:194
Code: f5 53 48 8b 74 24 10 48 89 fb 48 83 c7 18 e8 46 1c 02 fa 48 89 df e8 fe 6e 02 fa f7 c5 00 02 00 00 75 23 9c 58 f6 c4 02 75 37 01 00 00 00 e8 45 c2 f5 f9 65 8b 05 5e 26 49 05 85 c0 74 16 5b
RSP: 0018:ffffc90000007bd8 EFLAGS: 00000246
RAX: 0000000000000006 RBX: ffff888109f64000 RCX: 0000000000000002
RDX: 0000000000000000 RSI: ffffffff88d03c4d RDI: ffffffff878a7300
RBP: 0000000000000246 R08: 0000000000000001 R09: 0000000000000001
R10: ffffffff8aa491d7 R11: ffff888109ff3470 R12: ffff8881c6dd6810
R13: dffffc0000000000 R14: 1ffff92000000fad R15: ffff888109ff349b
FS: 0000000000000000(0000) GS:ffff888268bf4000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007ff11daa7dac CR3: 00000001351b2000 CR4: 00000000003506f0
Call Trace:
spin_unlock_irqrestore include/linux/spinlock.h:406 [inline]
dummy_timer+0x1e8b/0x3ad0 drivers/usb/gadget/udc/dummy_hcd.c:2012
__run_hrtimer kernel/time/hrtimer.c:1777 [inline]
__hrtimer_run_queues+0x202/0xc40 kernel/time/hrtimer.c:1841
hrtimer_run_softirq+0x17d/0x350 kernel/time/hrtimer.c:1858
handle_softirqs+0x208/0x940 kernel/softirq.c:622
__do_softirq kernel/softirq.c:656 [inline]
invoke_softirq kernel/softirq.c:496 [inline]
__irq_exit_rcu+0xfa/0x160 kernel/softirq.c:723
irq_exit_rcu+0x9/0x30 kernel/softirq.c:739
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1056 [inline]
sysvec_apic_timer_interrupt+0x90/0xb0 arch/x86/kernel/apic/apic.c:1056
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:unwind_get_return_address+0x5d/0xa0 arch/x86/kernel/unwind_orc.c:369
Code: cc cc 48 b8 00 00 00 00 00 fc ff df 48 8d 6b 48 48 89 ea 48 c1 ea 03 80 3c 02 00 75 36 48 8b 7b 48 e8 a7 bc 0f 00 85 c0 74 cf <48> b8 00 00 00 00 00 fc ff df 48 89 ea 48 c1 ea 03 80 3c 02 00 75
RSP: 0018:ffffc90002fee8e0 EFLAGS: 00000202
RAX: 0000000000000001 RBX: ffffc90002fee8f8 RCX: ffffc90002fee84c
RDX: 1ffff920005fdd28 RSI: ffffffff88ce314f RDI: ffffffff838648b4
RBP: ffffc90002fee940 R08: 0000000000000001 R09: 00000000ae06e9b8
R10: 0000000000000002 R11: 00000000000285c8 R12: ffffffff816b1980
R13: ffffc90002fee9b8 R14: 0000000000000000 R15: ffff88811b7057c0
arch_stack_walk+0xa6/0x100 arch/x86/kernel/stacktrace.c:26
stack_trace_save+0x8e/0xc0 kernel/stacktrace.c:122
kasan_save_stack+0x33/0x60 mm/kasan/common.c:56
kasan_save_track+0x14/0x30 mm/kasan/common.c:77
poison_kmalloc_redzone mm/kasan/common.c:397 [inline]
__kasan_kmalloc+0x8f/0xa0 mm/kasan/common.c:414
kasan_kmalloc include/linux/kasan.h:262 [inline]
__do_kmalloc_node mm/slub.c:5657 [inline]
__kmalloc_node_track_caller_noprof+0x351/0x8e0 mm/slub.c:5764
kmalloc_reserve+0xef/0x2c0 net/core/skbuff.c:608
__alloc_skb+0x186/0x410 net/core/skbuff.c:690
__netdev_alloc_skb+0x7a/0x920 net/core/skbuff.c:754
netdev_alloc_skb include/linux/skbuff.h:3484 [inline]
dev_alloc_skb include/linux/skbuff.h:3497 [inline]
ath6kl_usb_post_recv_transfers.constprop.0+0x55/0x400 drivers/net/wireless/ath/ath6kl/usb.c:428
ath6kl_usb_start_recv_pipes drivers/net/wireless/ath/ath6kl/usb.c:498 [inline]
hif_start drivers/net/wireless/ath/ath6kl/usb.c:703 [inline]
ath6kl_usb_power_on+0x8e/0x160 drivers/net/wireless/ath/ath6kl/usb.c:1062
ath6kl_hif_power_on drivers/net/wireless/ath/ath6kl/hif-ops.h:136 [inline]
ath6kl_core_init+0x17e/0x11b0 drivers/net/wireless/ath/ath6kl/core.c:97
ath6kl_usb_probe+0xcee/0x1440 drivers/net/wireless/ath/ath6kl/usb.c:1168
usb_probe_interface+0x303/0xa80 drivers/usb/core/driver.c:396
call_driver_probe drivers/base/dd.c:581 [inline]
really_probe+0x241/0xb20 drivers/base/dd.c:659
__driver_probe_device+0x1de/0x470 drivers/base/dd.c:801
driver_probe_device+0x4c/0x1b0 drivers/base/dd.c:831
__device_attach_driver+0x1df/0x350 drivers/base/dd.c:959
bus_for_each_drv+0x159/0x1e0 drivers/base/bus.c:500
__device_attach+0x1e4/0x4e0 drivers/base/dd.c:1031
device_initial_probe+0xaa/0xc0 drivers/base/dd.c:1086
bus_probe_device+0x64/0x150 drivers/base/bus.c:574
device_add+0x116e/0x1980 drivers/base/core.c:3689
usb_set_configuration+0x1187/0x1e50 drivers/usb/core/message.c:2210
usb_generic_driver_probe+0xb1/0x110 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+0x241/0xb20 drivers/base/dd.c:659
__driver_probe_device+0x1de/0x470 drivers/base/dd.c:801
driver_probe_device+0x4c/0x1b0 drivers/base/dd.c:831
__device_attach_driver+0x1df/0x350 drivers/base/dd.c:959
bus_for_each_drv+0x159/0x1e0 drivers/base/bus.c:500
__device_attach+0x1e4/0x4e0 drivers/base/dd.c:1031
device_initial_probe+0xaa/0xc0 drivers/base/dd.c:1086
bus_probe_device+0x64/0x150 drivers/base/bus.c:574
device_add+0x116e/0x1980 drivers/base/core.c:3689
usb_new_device+0xd07/0x1a90 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+0x31bf/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