rcu: INFO: rcu_preempt self-detected stall on CPU
rcu: 	0-....: (10499 ticks this GP) idle=86b4/1/0x4000000000000000 softirq=18800/18803 fqs=4281
rcu: 	         hardirqs   softirqs   csw/system
rcu: 	 number:   804459          0            0
rcu: 	cputime:    37587      14882           61   ==> 52470(ms)
rcu: 	(t=10500 jiffies g=10069 q=3617 ncpus=2)
CPU: 0 UID: 0 PID: 6457 Comm: syz.5.89 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014
RIP: 0010:rcu_is_watching+0x4e/0xb0
Code: ff df 4c 8d 34 dd 10 ed bd 8d 4c 89 f0 48 c1 e8 03 42 80 3c 38 00 74 08 4c 89 f7 e8 7c c2 7c 00 48 c7 c3 98 6f a1 92 49 03 1e <48> 89 d8 48 c1 e8 03 42 0f b6 04 38 84 c0 75 34 8b 03 65 ff 0d a9
RSP: 0018:ffffc90000006a78 EFLAGS: 00000283
RAX: 1ffffffff1b7bda2 RBX: ffff88804b032f98 RCX: 57d9bf94226d5000
RDX: 0000000000000000 RSI: ffffffff8be332e0 RDI: ffffffff8be332a0
RBP: ffffffff8172c195 R08: 0000000000000000 R09: 0000000000000000
R10: ffffc90000006c68 R11: fffff52000000d99 R12: 0000000000000002
R13: ffffffff8e139ea0 R14: ffffffff8dbded10 R15: dffffc0000000000
FS:  00007fa969cbd6c0(0000) GS:ffff8880b861c000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000056118e669680 CR3: 0000000100090000 CR4: 00000000000006f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000010602
Call Trace:
 <IRQ>
 lock_acquire+0x5f/0x360
 unwind_next_frame+0xc2/0x2390
 __unwind_start+0x5b9/0x760
 arch_stack_walk+0xe4/0x150
 stack_trace_save+0x9c/0xe0
 kasan_save_stack+0x3e/0x60
 kasan_record_aux_stack+0xbd/0xd0
 kvfree_call_rcu+0xbb/0x410
 cfg80211_update_known_bss+0x634/0x1330
 __cfg80211_bss_update+0x147/0x2120
 cfg80211_inform_single_bss_data+0xba9/0x1ac0
 cfg80211_inform_bss_data+0x1fb/0x3b30
 cfg80211_inform_bss_frame_data+0x3d7/0x730
 ieee80211_bss_info_update+0x746/0x9e0
 ieee80211_scan_rx+0x593/0xa20
 ieee80211_rx_list+0x201c/0x2a90
 ieee80211_rx_napi+0x1a8/0x3d0
 ieee80211_handle_queued_frames+0xe8/0x1f0
 tasklet_action_common+0x36c/0x580
 handle_softirqs+0x286/0x870
 __irq_exit_rcu+0xca/0x1f0
 irq_exit_rcu+0x9/0x30
 sysvec_apic_timer_interrupt+0xa6/0xc0
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x1a/0x20
RIP: 0010:__schedule+0x0/0x4cc0
Code: a9 f6 45 89 f8 89 d9 48 8b 5c 24 08 e9 ee fe ff ff cc cc cc cc cc cc cc cc cc 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 <f3> 0f 1e fa 55 48 89 e5 41 57 41 56 41 55 41 54 53 48 83 e4 e0 48
RSP: 0018:ffffc90002a6fbd8 EFLAGS: 00000282
RAX: 57d9bf94226d5000 RBX: 0000000000000000 RCX: 57d9bf94226d5000
RDX: 0000000000000000 RSI: ffffffff8d9b6a0a RDI: 0000000000000001
RBP: ffffc90002a6fc80 R08: ffffffff8fa38037 R09: 1ffffffff1f47006
R10: dffffc0000000000 R11: fffffbfff1f47007 R12: 0000000000000000
R13: 0000000000000000 R14: dffffc0000000000 R15: 1ffff9200054df7c
 preempt_schedule_irq+0xb5/0x150
 irqentry_exit+0x6f/0x90
 asm_sysvec_apic_timer_interrupt+0x1a/0x20
RIP: 0010:task_mm_cid_work+0x3a3/0x760
Code: 92 48 81 c3 08 0b 00 00 48 89 d8 48 c1 e8 03 48 b9 00 00 00 00 00 fc ff df 80 3c 08 00 74 08 48 89 df e8 b0 57 91 00 48 8b 1b <e8> a8 75 e7 09 85 c0 74 0d e8 df 66 13 00 85 c0 0f 84 04 01 00 00
RSP: 0018:ffffc90002a6fd40 EFLAGS: 00000246
RAX: 1ffff11026cc7551 RBX: ffff888020223980 RCX: dffffc0000000000
RDX: 0000000000000001 RSI: ffffffff8be332e0 RDI: ffffffff8be332a0
RBP: ffffc90002a6fe10 R08: 0000000000000000 R09: ffffffff8191c89f
R10: dffffc0000000000 R11: fffff5200054dfb5 R12: 0000000000000001
R13: ffffffff8191c89f R14: ffff8881a3c1c000 R15: ffffe8ffffc2f1c0
 task_work_run+0x1d4/0x260
 resume_user_mode_work+0x5e/0x80
 irqentry_exit_to_user_mode+0x90/0x120
 exc_page_fault+0x9f/0xf0
 asm_exc_page_fault+0x26/0x30
RIP: 0033:0x7fa968c5e9ad
Code: 00 00 00 64 f0 83 04 25 90 ff ff ff 01 64 48 8b 04 25 00 00 00 00 48 8d b8 c8 fe ff ff e8 ab c1 0c 00 85 c0 0f 84 a3 01 00 00 <64> f0 83 2c 25 90 ff ff ff 01 e8 f4 9b 0b 00 48 8b 0c 24 8b 00 48
RSP: 002b:00007fa969cbd060 EFLAGS: 00010202
RAX: 0000000000000004 RBX: 00007fa968fb6090 RCX: 00007fa968e11e19
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 00002000000012c0
RBP: 00007fa968e11e19 R08: 0000000000000001 R09: 0000000000000000
R10: ffffffffffffffff R11: 0000000000000246 R12: 0000000000000000
R13: 00007fa968fb6128 R14: 00007fa968fb6090 R15: 00007ffed45555b8
 </TASK>
sched: DL replenish lagged too much
