rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: (detected by 1, t=10502 jiffies, g=69013, q=38 ncpus=2)
rcu: All QSes seen, last rcu_preempt kthread activity 10498 (4294993043-4294982545), jiffies_till_next_fqs=1, root ->qsmask 0x0
rcu: rcu_preempt kthread starved for 10498 jiffies! g69013 f0x2 RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=1
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:28328 pid:15 tgid:15 ppid:2 task_flags:0x208040 flags:0x00080000
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
rcu_gp_fqs_loop+0x1a9/0xb00 kernel/rcu/tree.c:2083
rcu_gp_kthread+0x21e/0x320 kernel/rcu/tree.c:2285
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
rcu: Stack dump where RCU GP kthread last ran:
CPU: 1 UID: 0 PID: 5226 Comm: kworker/1:3 Not tainted syzkaller #0 PREEMPT(voluntary)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/24/2026
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 06 01 38 fa 48 89 df e8 ee 4e 38 fa f7 c5 00 02 00 00 75 23 9c 58 f6 c4 02 75 37 01 00 00 00 e8 e5 d9 2b fa 65 8b 05 5e 30 75 05 85 c0 74 16 5b
RSP: 0018:ffffc900001a8c00 EFLAGS: 00000246
RAX: 0000000000000002 RBX: ffff88810a33c000 RCX: 0000000000000004
RDX: 0000000000000000 RSI: ffffffff88dec92b RDI: ffffffff878e97a0
RBP: 0000000000000246 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000001 R11: 0000000000000000 R12: ffff8881b78ed110
R13: ffff88810a7ce470 R14: 1ffff920000351b0 R15: dffffc0000000000
FS: 0000000000000000(0000) GS:ffff888268a6a000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f2a19547dac CR3: 00000000092a8000 CR4: 00000000003506f0
Call Trace:
spin_unlock_irqrestore include/linux/spinlock.h:406 [inline]
dummy_timer+0x1d58/0x3670 drivers/usb/gadget/udc/dummy_hcd.c:2012
__run_hrtimer kernel/time/hrtimer.c:1777 [inline]
__hrtimer_run_queues+0x516/0x990 kernel/time/hrtimer.c:1841
hrtimer_run_softirq+0x17d/0x350 kernel/time/hrtimer.c:1858
handle_softirqs+0x1dd/0x8f0 kernel/softirq.c:622
__do_softirq kernel/softirq.c:656 [inline]
invoke_softirq kernel/softirq.c:496 [inline]
__irq_exit_rcu+0xed/0x150 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+0x8f/0xb0 arch/x86/kernel/apic/apic.c:1056
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:orc_find arch/x86/kernel/unwind_orc.c:220 [inline]
RIP: 0010:unwind_next_frame+0x1bb/0x1ea0 arch/x86/kernel/unwind_orc.c:510
Code: 00 4d 85 ff 0f 84 f0 05 00 00 49 81 ff 00 00 00 81 0f 82 25 02 00 00 49 81 ff 18 cc 56 87 0f 83 18 02 00 00 8b 35 05 a8 87 07 <4c> 89 f8 48 2d 00 00 00 81 48 c1 e8 08 8d 56 ff 41 89 c3 39 d0 0f
RSP: 0018:ffffc9000228e390 EFLAGS: 00000297
RAX: 0000000000000000 RBX: 0000000000000001 RCX: 1ffff92000451c89
RDX: dffffc0000000000 RSI: 00000000000656ce RDI: ffffffff88f6cbe8
RBP: ffffc9000228e448 R08: 00000000fab6b97c R09: 0000000000000007
R10: 0000000000000200 R11: 0000000000000000 R12: ffffc9000228e450
R13: ffffc9000228e400 R14: ffffc9000228e435 R15: ffffffff820ae343
arch_stack_walk+0x94/0xf0 arch/x86/kernel/stacktrace.c:25
stack_trace_save+0x8e/0xc0 kernel/stacktrace.c:122
save_stack+0x162/0x1e0 mm/page_owner.c:165
__set_page_owner+0x8c/0x540 mm/page_owner.c:341
set_page_owner include/linux/page_owner.h:32 [inline]
post_alloc_hook+0x1e1/0x250 mm/page_alloc.c:1884
prep_new_page mm/page_alloc.c:1892 [inline]
get_page_from_freelist+0xd57/0x3b20 mm/page_alloc.c:3945
__alloc_frozen_pages_noprof+0x269/0x2230 mm/page_alloc.c:5240
alloc_pages_mpol+0xe8/0x410 mm/mempolicy.c:2486
alloc_slab_page mm/slub.c:3075 [inline]
allocate_slab mm/slub.c:3248 [inline]
new_slab+0x2c4/0x440 mm/slub.c:3302
___slab_alloc+0xda3/0x1ca0 mm/slub.c:4656
__slab_alloc.isra.0+0x63/0x110 mm/slub.c:4779
__slab_alloc_node mm/slub.c:4855 [inline]
slab_alloc_node mm/slub.c:5251 [inline]
__do_kmalloc_node mm/slub.c:5656 [inline]
__kmalloc_node_track_caller_noprof+0x5d4/0x9a0 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/0x8f0 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+0x55/0x3d0 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+0x173/0x11b0 drivers/net/wireless/ath/ath6kl/core.c:97
ath6kl_usb_probe+0xcd0/0x13e0 drivers/net/wireless/ath/ath6kl/usb.c:1168
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