rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	Tasks blocked on level-0 rcu_node (CPUs 0-1): P5909/1:b..l
rcu: 	(detected by 1, t=10502 jiffies, g=11005, q=4539 ncpus=2)
task:kworker/1:6     state:R  running task     stack:23896 pid:5909  tgid:5909  ppid:2      flags:0x00004000
Workqueue: events request_firmware_work_func
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5369 [inline]
 __schedule+0x1850/0x4c30 kernel/sched/core.c:6756
 preempt_schedule_irq+0xfb/0x1c0 kernel/sched/core.c:7078
 irqentry_exit+0x5e/0x90 kernel/entry/common.c:354
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
RIP: 0010:arch_stack_walk+0x100/0x150 arch/x86/kernel/stacktrace.c:27
Code: 70 ff ff ff 4c 89 e6 4c 89 fa e8 bb da 09 00 83 bd 70 ff ff ff 00 74 37 48 8d 9d 70 ff ff ff 48 89 df e8 63 b1 09 00 48 85 c0 <74> 23 4c 89 f7 48 89 c6 4d 89 eb e8 c0 9b 89 0a 84 c0 74 11 48 89
RSP: 0018:ffffc900035972e0 EFLAGS: 00000282
RAX: ffffffff81f7587f RBX: ffffc900035972e0 RCX: ffffffff91792000
RDX: ffffffff91942801 RSI: ffffc90003590000 RDI: ffffffff81f7587f
RBP: ffffc90003597370 R08: ffffc90003597620 R09: ffffc90003597330
R10: dffffc0000000000 R11: fffff520006b2e68 R12: ffff88802bcbbc00
R13: ffffffff818b39e0 R14: ffffc900035973c0 R15: 0000000000000000
 stack_trace_save+0x118/0x1d0 kernel/stacktrace.c:122
 save_stack+0xfb/0x1f0 mm/page_owner.c:156
 __reset_page_owner+0x76/0x430 mm/page_owner.c:297
 reset_page_owner include/linux/page_owner.h:25 [inline]
 free_pages_prepare mm/page_alloc.c:1127 [inline]
 free_unref_page+0xd3f/0x1010 mm/page_alloc.c:2657
 discard_slab mm/slub.c:2688 [inline]
 __put_partials+0x160/0x1c0 mm/slub.c:3157
 put_cpu_partial+0x17c/0x250 mm/slub.c:3232
 __slab_free+0x290/0x380 mm/slub.c:4483
 qlink_free mm/kasan/quarantine.c:163 [inline]
 qlist_free_all+0x9a/0x140 mm/kasan/quarantine.c:179
 kasan_quarantine_reduce+0x14f/0x170 mm/kasan/quarantine.c:286
 __kasan_slab_alloc+0x23/0x80 mm/kasan/common.c:329
 kasan_slab_alloc include/linux/kasan.h:250 [inline]
 slab_post_alloc_hook mm/slub.c:4119 [inline]
 slab_alloc_node mm/slub.c:4168 [inline]
 kmem_cache_alloc_node_noprof+0x1d9/0x380 mm/slub.c:4220
 kmalloc_reserve+0xa8/0x2a0 net/core/skbuff.c:587
 __alloc_skb+0x1f3/0x440 net/core/skbuff.c:678
 alloc_skb include/linux/skbuff.h:1323 [inline]
 ath9k_hif_usb_alloc_reg_in_urbs drivers/net/wireless/ath/ath9k/hif_usb.c:989 [inline]
 ath9k_hif_usb_alloc_urbs+0xb75/0x10f0 drivers/net/wireless/ath/ath9k/hif_usb.c:1048
 ath9k_hif_usb_dev_init drivers/net/wireless/ath/ath9k/hif_usb.c:1134 [inline]
 ath9k_hif_usb_firmware_cb+0x12f/0x4b0 drivers/net/wireless/ath/ath9k/hif_usb.c:1267
 request_firmware_work_func+0x1a6/0x280 drivers/base/firmware_loader/main.c:1196
 process_one_work kernel/workqueue.c:3229 [inline]
 process_scheduled_works+0xa68/0x1840 kernel/workqueue.c:3310
 worker_thread+0x870/0xd30 kernel/workqueue.c:3391
 kthread+0x2f2/0x390 kernel/kthread.c:389
 ret_from_fork+0x4d/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
 </TASK>