rcu: INFO: rcu_preempt self-detected stall on CPU
rcu: 	0-....: (4609 ticks this GP) idle=27a/1/0x4000000000000000 softirq=9466/9466 fqs=2961 
	(t=10502 jiffies g=9265 q=69)
NMI backtrace for cpu 0
CPU: 0 PID: 8824 Comm: syz-executor280 Not tainted 5.11.0-rc6-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 <IRQ>
 __dump_stack lib/dump_stack.c:79 [inline]
 dump_stack+0x107/0x163 lib/dump_stack.c:120
 nmi_cpu_backtrace.cold+0x44/0xd7 lib/nmi_backtrace.c:105
 nmi_trigger_cpumask_backtrace+0x1b3/0x230 lib/nmi_backtrace.c:62
 trigger_single_cpu_backtrace include/linux/nmi.h:164 [inline]
 rcu_dump_cpu_stacks+0x1f4/0x230 kernel/rcu/tree_stall.h:337
 print_cpu_stall kernel/rcu/tree_stall.h:569 [inline]
 check_cpu_stall kernel/rcu/tree_stall.h:643 [inline]
 rcu_pending kernel/rcu/tree.c:3751 [inline]
 rcu_sched_clock_irq.cold+0x48e/0xedf kernel/rcu/tree.c:2580
 update_process_times+0x16d/0x200 kernel/time/timer.c:1782
 tick_sched_handle+0x9b/0x180 kernel/time/tick-sched.c:226
 tick_sched_timer+0x1b0/0x2d0 kernel/time/tick-sched.c:1369
 __run_hrtimer kernel/time/hrtimer.c:1519 [inline]
 __hrtimer_run_queues+0x1c0/0xe40 kernel/time/hrtimer.c:1583
 hrtimer_interrupt+0x334/0x940 kernel/time/hrtimer.c:1645
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1085 [inline]
 __sysvec_apic_timer_interrupt+0x146/0x540 arch/x86/kernel/apic/apic.c:1102
 run_sysvec_on_irqstack_cond arch/x86/include/asm/irq_stack.h:91 [inline]
 sysvec_apic_timer_interrupt+0x48/0x100 arch/x86/kernel/apic/apic.c:1096
 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:629
RIP: 0010:preempt_count_add+0x65/0x140 kernel/sched/core.c:4740
Code: f1 65 b4 7e 85 d2 75 11 65 8b 05 e6 65 b4 7e 0f b6 c0 3d f4 00 00 00 7f 64 65 8b 05 d5 65 b4 7e 25 ff ff ff 7f 39 c3 74 03 5b <5d> c3 48 8b 5c 24 10 48 89 df e8 4c 7e 0b 00 85 c0 75 35 65 48 8b
RSP: 0018:ffffc90000007680 EFLAGS: 00000297
RAX: 0000000000000102 RBX: 1ffff92000000eda RCX: 1ffffffff1e3e6cc
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000001
RBP: 0000000000000002 R08: ffffffff8d855a82 R09: ffffffff8d855a86
R10: 0000000000082083 R11: 0000000000000001 R12: ffffc900000077b0
R13: 0000000000000000 R14: ffff888030840000 R15: ffffc90000007768
 unwind_next_frame+0x11f/0x1f90 arch/x86/kernel/unwind_orc.c:428
 arch_stack_walk+0x7d/0xe0 arch/x86/kernel/stacktrace.c:25
 stack_trace_save+0x8c/0xc0 kernel/stacktrace.c:121
 kasan_save_stack+0x1b/0x40 mm/kasan/common.c:38
 kasan_set_track mm/kasan/common.c:46 [inline]
 set_alloc_info mm/kasan/common.c:401 [inline]
 ____kasan_kmalloc.constprop.0+0x82/0xa0 mm/kasan/common.c:429
 kasan_slab_alloc include/linux/kasan.h:209 [inline]
 slab_post_alloc_hook mm/slab.h:512 [inline]
 slab_alloc_node mm/slub.c:2892 [inline]
 kmem_cache_alloc_node+0x1e0/0x470 mm/slub.c:2928
 __alloc_skb+0x71/0x5a0 net/core/skbuff.c:198
 __netdev_alloc_skb+0x70/0x400 net/core/skbuff.c:446
 netdev_alloc_skb include/linux/skbuff.h:2832 [inline]
 dev_alloc_skb include/linux/skbuff.h:2845 [inline]
 __ieee80211_beacon_get+0xebe/0x1aa0 net/mac80211/tx.c:4814
 ieee80211_beacon_get_tim+0x88/0x910 net/mac80211/tx.c:4928
 ieee80211_beacon_get include/net/mac80211.h:4918 [inline]
 mac80211_hwsim_beacon_tx+0x111/0x910 drivers/net/wireless/mac80211_hwsim.c:1729
 __iterate_interfaces+0x1e5/0x520 net/mac80211/util.c:793
 ieee80211_iterate_active_interfaces_atomic+0x8d/0x170 net/mac80211/util.c:829
 mac80211_hwsim_beacon+0xd5/0x1a0 drivers/net/wireless/mac80211_hwsim.c:1782
 __run_hrtimer kernel/time/hrtimer.c:1519 [inline]
 __hrtimer_run_queues+0x609/0xe40 kernel/time/hrtimer.c:1583
 hrtimer_run_softirq+0x17b/0x360 kernel/time/hrtimer.c:1600
 __do_softirq+0x29b/0x9f6 kernel/softirq.c:343
 asm_call_irq_on_stack+0xf/0x20
 </IRQ>
 __run_on_irqstack arch/x86/include/asm/irq_stack.h:26 [inline]
 run_on_irqstack_cond arch/x86/include/asm/irq_stack.h:77 [inline]
 do_softirq_own_stack+0xaa/0xd0 arch/x86/kernel/irq_64.c:77
 invoke_softirq kernel/softirq.c:226 [inline]
 __irq_exit_rcu kernel/softirq.c:420 [inline]
 irq_exit_rcu+0x134/0x200 kernel/softirq.c:432
 sysvec_apic_timer_interrupt+0x4d/0x100 arch/x86/kernel/apic/apic.c:1096
 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:629
RIP: 0010:schedule_debug kernel/sched/core.c:4826 [inline]
RIP: 0010:__schedule+0x129/0x21a0 kernel/sched/core.c:4972
Code: 48 89 fa 48 c1 ea 03 80 3c 02 00 0f 85 fe 1a 00 00 48 b8 00 00 00 00 00 fc ff df 4d 8b 7d 20 4c 89 fa 48 c1 ea 03 80 3c 02 00 <0f> 85 c7 1b 00 00 49 81 3f 9d 6e ac 57 0f 85 44 20 00 00 49 8d 45
RSP: 0018:ffffc900028cf7f0 EFLAGS: 00000246
RAX: dffffc0000000000 RBX: 0000000000000001 RCX: 1ffff92000519f06
RDX: 1ffff92000519000 RSI: 0000000000000001 RDI: ffff888030840020
RBP: ffffc900028cf8b8 R08: 0000000000000001 R09: ffffffff8ee667c7
R10: fffffbfff1dcccf8 R11: 0000000000000001 R12: ffff8880b9e34c40
R13: ffff888030840000 R14: 0000000000034c40 R15: ffffc900028c8000
 preempt_schedule_irq+0x4e/0x90 kernel/sched/core.c:5340
 irqentry_exit_cond_resched kernel/entry/common.c:393 [inline]
 irqentry_exit_cond_resched kernel/entry/common.c:385 [inline]
 irqentry_exit+0x7a/0xa0 kernel/entry/common.c:423
 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:629
RIP: 0010:unlock_anon_vma_root mm/rmap.c:252 [inline]
RIP: 0010:unlink_anon_vmas+0x31e/0x830 mm/rmap.c:418
Code: fc ff df 48 89 fa 48 c1 ea 03 0f b6 14 02 48 89 f8 83 e0 07 83 c0 03 38 d0 7c 08 84 d2 0f 85 f6 04 00 00 83 ab a4 00 00 00 01 <e8> 0d 7d c8 ff 4d 85 f6 0f 84 e6 02 00 00 e8 ff 7c c8 ff 49 8d 7e
RSP: 0018:ffffc900028cf998 EFLAGS: 00000246
RAX: 0000000000000007 RBX: ffff8880183df800 RCX: 0000000000000000
RDX: 0000000000000000 RSI: ffffffff81aa3e26 RDI: ffff8880183df8a4
RBP: ffff8880280fe698 R08: 0000000000000001 R09: ffffffff8ee667c7
R10: fffffbfff1dcccf8 R11: 0000000000000000 R12: ffff8880280f9478
R13: ffff8880280fe698 R14: ffff88801fd91e00 R15: ffff8880280fe6a8
 free_pgtables+0x1ab/0x2f0 mm/memory.c:415
 exit_mmap+0x2c0/0x5a0 mm/mmap.c:3221
 __mmput+0x122/0x470 kernel/fork.c:1082
 mmput+0x53/0x60 kernel/fork.c:1103
 exit_mm kernel/exit.c:501 [inline]
 do_exit+0xb6a/0x2ae0 kernel/exit.c:812
 do_group_exit+0x125/0x310 kernel/exit.c:922
 get_signal+0x427/0x20f0 kernel/signal.c:2773
 arch_do_signal_or_restart+0x2a8/0x1eb0 arch/x86/kernel/signal.c:811
 handle_signal_work kernel/entry/common.c:147 [inline]
 exit_to_user_mode_loop kernel/entry/common.c:171 [inline]
 exit_to_user_mode_prepare+0x148/0x250 kernel/entry/common.c:201
 irqentry_exit_to_user_mode+0x5/0x30 kernel/entry/common.c:315
 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:629
RIP: 0033:0x4470e9
Code: Unable to access opcode bytes at RIP 0x4470bf.
RSP: 002b:00007ffc886bc1e8 EFLAGS: 00000246
RAX: 0000000000000000 RBX: 0000000000000003 RCX: 00000000004470e9
RDX: 0000000000042000 RSI: 0000000000000004 RDI: 0000000000000003
RBP: 0000000000000000 R08: 00007ffc00000004 R09: 00007ffc00000004
R10: 0000000000000000 R11: 0000000000000246 R12: 000000000010fb1a
R13: 00007ffc886bc2a0 R14: 00007ffc886bc290 R15: 00007ffc886bc228