rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
	(detected by 1, t=10502 jiffies, g=275041, q=28)
rcu: All QSes seen, last rcu_preempt kthread activity 10503 (4295115206-4295104703), jiffies_till_next_fqs=1, root ->qsmask 0x0
rcu: rcu_preempt kthread starved for 10504 jiffies! g275041 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:28192 pid:   14 ppid:     2 flags:0x00004000
Call Trace:
 context_switch kernel/sched/core.c:4339 [inline]
 __schedule+0x916/0x23e0 kernel/sched/core.c:5147
 schedule+0xcf/0x270 kernel/sched/core.c:5226
 schedule_timeout+0x14a/0x250 kernel/time/timer.c:1892
 rcu_gp_fqs_loop kernel/rcu/tree.c:2004 [inline]
 rcu_gp_kthread+0xd07/0x2300 kernel/rcu/tree.c:2177
 kthread+0x3b1/0x4a0 kernel/kthread.c:313
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294
rcu: Stack dump where RCU GP kthread last ran:
NMI backtrace for cpu 1
CPU: 1 PID: 25710 Comm: syz-executor.1 Not tainted 5.13.0-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+0x141/0x1d7 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_check_gp_kthread_starvation.cold+0x1cc/0x1d1 kernel/rcu/tree_stall.h:478
 print_other_cpu_stall kernel/rcu/tree_stall.h:583 [inline]
 check_cpu_stall kernel/rcu/tree_stall.h:708 [inline]
 rcu_pending kernel/rcu/tree.c:3911 [inline]
 rcu_sched_clock_irq+0x1d46/0x2080 kernel/rcu/tree.c:2649
 update_process_times+0x16d/0x200 kernel/time/timer.c:1796
 tick_sched_handle+0x9b/0x180 kernel/time/tick-sched.c:226
 tick_sched_timer+0x1b0/0x2d0 kernel/time/tick-sched.c:1374
 __run_hrtimer kernel/time/hrtimer.c:1537 [inline]
 __hrtimer_run_queues+0x1c0/0xe40 kernel/time/hrtimer.c:1601
 hrtimer_interrupt+0x330/0xa00 kernel/time/hrtimer.c:1663
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1089 [inline]
 __sysvec_apic_timer_interrupt+0x146/0x540 arch/x86/kernel/apic/apic.c:1106
 sysvec_apic_timer_interrupt+0x40/0xc0 arch/x86/kernel/apic/apic.c:1100
 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:647
RIP: 0010:lock_acquire+0x1ef/0x740 kernel/locking/lockdep.c:5480
Code: 72 a7 7e 83 f8 01 0f 85 ee 03 00 00 9c 58 f6 c4 02 0f 85 d9 03 00 00 48 83 7c 24 08 00 74 01 fb 48 b8 00 00 00 00 00 fc ff df <48> 01 c3 48 c7 03 00 00 00 00 48 c7 43 08 00 00 00 00 48 8b 84 24
RSP: 0018:ffffc90000dc0d50 EFLAGS: 00000206
RAX: dffffc0000000000 RBX: 1ffff920001b81ac RCX: 00000000ef951384
RDX: 1ffff11011ebc13e RSI: 0000000000000101 RDI: 0000000000000000
RBP: 0000000000000000 R08: 0000000000000000 R09: ffffffff902288a7
R10: fffffbfff2045114 R11: 0000000000000001 R12: 0000000000000002
R13: ffffffff8bf79620 R14: 0000000000000000 R15: 0000000000000000
 rcu_lock_acquire include/linux/rcupdate.h:267 [inline]
 rcu_read_lock include/linux/rcupdate.h:657 [inline]
 ieee80211_rx_napi+0xaa/0x3d0 net/mac80211/rx.c:4923
 ieee80211_rx include/net/mac80211.h:4528 [inline]
 ieee80211_tasklet_handler+0xd4/0x130 net/mac80211/main.c:235
 tasklet_action_common.constprop.0+0x201/0x2e0 kernel/softirq.c:784
 __do_softirq+0x29b/0x9f6 kernel/softirq.c:559
 invoke_softirq kernel/softirq.c:433 [inline]
 __irq_exit_rcu+0x136/0x200 kernel/softirq.c:637
 irq_exit_rcu+0x5/0x20 kernel/softirq.c:649
 sysvec_apic_timer_interrupt+0x93/0xc0 arch/x86/kernel/apic/apic.c:1100
 </IRQ>
 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:647
RIP: 0010:preempt_schedule_irq+0x49/0x90 kernel/sched/core.c:5535
Code: 55 53 65 48 8b 1c 25 00 f0 01 00 48 89 dd 48 c1 ed 03 48 01 c5 bf 01 00 00 00 e8 22 6f 36 f8 e8 dd 58 62 f8 fb bf 01 00 00 00 <e8> 92 ce ff ff 9c 58 fa f6 c4 02 75 27 bf 01 00 00 00 e8 70 5d 36
RSP: 0018:ffffc90003c57798 EFLAGS: 00000206
RAX: 000000000028045f RBX: ffff88808f5e0000 RCX: 1ffffffff20478d2
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000001
RBP: ffffed1011ebc000 R08: 0000000000000001 R09: ffffffff902288d7
R10: 0000000000000001 R11: 0000000000000001 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
 irqentry_exit+0x31/0x80 kernel/entry/common.c:427
 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:647
RIP: 0010:__slab_alloc.constprop.0+0x68/0xf0 mm/slub.c:2801
Code: 0e 8b 4c 89 f9 44 89 f2 44 89 ee 48 89 ef 4d 01 e0 e8 1c f4 ff ff 49 89 c4 9c 58 f6 c4 02 75 53 48 85 db 74 01 fb 48 83 c4 08 <4c> 89 e0 5b 5d 41 5c 41 5d 41 5e 41 5f c3 e8 75 59 c1 ff 4c 8b 65
RSP: 0018:ffffc90003c57868 EFLAGS: 00000282
RAX: 0000000000000002 RBX: 0000000000000200 RCX: 1ffffffff20478d2
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: ffff888011042140 R08: 0000000000000001 R09: ffffffff902288d7
R10: 0000000000000001 R11: 0000000000000000 R12: ffff88806f060000
R13: 0000000000000dc0 R14: 00000000ffffffff R15: ffffffff87038920
 slab_alloc_node mm/slub.c:2880 [inline]
 slab_alloc mm/slub.c:2922 [inline]
 __kmalloc+0x315/0x330 mm/slub.c:4050
 kmalloc include/linux/slab.h:561 [inline]
 sk_prot_alloc+0x110/0x290 net/core/sock.c:1711
 sk_alloc+0x32/0xbd0 net/core/sock.c:1764
 tun_chr_open+0x7b/0x540 drivers/net/tun.c:3361
 misc_open+0x372/0x4a0 drivers/char/misc.c:141
 chrdev_open+0x266/0x770 fs/char_dev.c:414
 do_dentry_open+0x4b9/0x11b0 fs/open.c:826
 do_open fs/namei.c:3361 [inline]
 path_openat+0x1c0e/0x27e0 fs/namei.c:3494
 do_filp_open+0x190/0x3d0 fs/namei.c:3521
 do_sys_openat2+0x16d/0x420 fs/open.c:1187
 do_sys_open fs/open.c:1203 [inline]
 __do_sys_openat fs/open.c:1219 [inline]
 __se_sys_openat fs/open.c:1214 [inline]
 __x64_sys_openat+0x13f/0x1f0 fs/open.c:1214
 do_syscall_64+0x3a/0xb0 arch/x86/entry/common.c:47
 entry_SYSCALL_64_after_hwframe+0x44/0xae
RIP: 0033:0x4665d9
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 bc ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f3a80a16188 EFLAGS: 00000246 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 000000000056bf80 RCX: 00000000004665d9
RDX: 0000000000000000 RSI: 0000000020000040 RDI: ffffffffffffff9c
RBP: 00000000004bfcb9 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 000000000056bf80
R13: 00007ffc338ba8ef R14: 00007f3a80a16300 R15: 0000000000022000

================================
WARNING: inconsistent lock state
5.13.0-rc6-syzkaller #0 Not tainted
--------------------------------
inconsistent {IN-HARDIRQ-W} -> {HARDIRQ-ON-W} usage.
syz-executor.1/25710 [HC0[0]:SC1[1]:HE0:SE0] takes:
ffffffff8bf82218 (rcu_node_0){?.-.}-{2:2}, at: print_other_cpu_stall kernel/rcu/tree_stall.h:542 [inline]
ffffffff8bf82218 (rcu_node_0){?.-.}-{2:2}, at: check_cpu_stall kernel/rcu/tree_stall.h:708 [inline]
ffffffff8bf82218 (rcu_node_0){?.-.}-{2:2}, at: rcu_pending kernel/rcu/tree.c:3911 [inline]
ffffffff8bf82218 (rcu_node_0){?.-.}-{2:2}, at: rcu_sched_clock_irq+0xc63/0x2080 kernel/rcu/tree.c:2649
{IN-HARDIRQ-W} state was registered at:
  lock_acquire kernel/locking/lockdep.c:5512 [inline]
  lock_acquire+0x1ab/0x740 kernel/locking/lockdep.c:5477
  __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
  _raw_spin_lock_irqsave+0x39/0x50 kernel/locking/spinlock.c:159
  rcu_exp_handler+0x1fc/0x440 kernel/rcu/tree_exp.h:679
  flush_smp_call_function_queue+0x34b/0x640 kernel/smp.c:663
  __sysvec_call_function_single+0x95/0x3d0 arch/x86/kernel/smp.c:248
  sysvec_call_function_single+0x8e/0xc0 arch/x86/kernel/smp.c:243
  asm_sysvec_call_function_single+0x12/0x20 arch/x86/include/asm/idtentry.h:655
  __sanitizer_cov_trace_pc+0x0/0x60 kernel/kcov.c:917
  __seqprop_spinlock_sequence include/linux/seqlock.h:277 [inline]
  set_root+0x1a6/0x5a0 fs/namei.c:912
  nd_jump_root+0x3c7/0x570 fs/namei.c:933
  path_init+0x1028/0x1910 fs/namei.c:2331
  path_lookupat+0x30/0x850 fs/namei.c:2411
  filename_lookup+0x1b1/0x570 fs/namei.c:2454
  init_mount+0x7e/0xf4 fs/init.c:22
  devtmpfs_setup+0x49/0xb2 drivers/base/devtmpfs.c:415
  devtmpfsd+0x1e/0x2a3 drivers/base/devtmpfs.c:432
  kthread+0x3b1/0x4a0 kernel/kthread.c:313
  ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294
irq event stamp: 10073777
hardirqs last  enabled at (10073776): [<ffffffff89200c02>] asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:647
hardirqs last disabled at (10073777): [<ffffffff8916f29b>] sysvec_apic_timer_interrupt+0xb/0xc0 arch/x86/kernel/apic/apic.c:1100
softirqs last  enabled at (10003264): [<ffffffff8145d336>] invoke_softirq kernel/softirq.c:433 [inline]
softirqs last  enabled at (10003264): [<ffffffff8145d336>] __irq_exit_rcu+0x136/0x200 kernel/softirq.c:637
softirqs last disabled at (10003267): [<ffffffff8145d336>] invoke_softirq kernel/softirq.c:433 [inline]
softirqs last disabled at (10003267): [<ffffffff8145d336>] __irq_exit_rcu+0x136/0x200 kernel/softirq.c:637

other info that might help us debug this:
 Possible unsafe locking scenario:

       CPU0
       ----
  lock(rcu_node_0);
  <Interrupt>
    lock(rcu_node_0);

 *** DEADLOCK ***

3 locks held by syz-executor.1/25710:
 #0: ffffffff8c99e7a8 (misc_mtx){+.+.}-{3:3}, at: misc_open+0x55/0x4a0 drivers/char/misc.c:107
 #1: ffffffff8bf79620 (rcu_read_lock){....}-{1:2}, at: ieee80211_rx_napi+0x0/0x3d0 arch/x86/include/asm/bitops.h:207
 #2: ffffffff8bf82218 (rcu_node_0){?.-.}-{2:2}, at: print_other_cpu_stall kernel/rcu/tree_stall.h:542 [inline]
 #2: ffffffff8bf82218 (rcu_node_0){?.-.}-{2:2}, at: check_cpu_stall kernel/rcu/tree_stall.h:708 [inline]
 #2: ffffffff8bf82218 (rcu_node_0){?.-.}-{2:2}, at: rcu_pending kernel/rcu/tree.c:3911 [inline]
 #2: ffffffff8bf82218 (rcu_node_0){?.-.}-{2:2}, at: rcu_sched_clock_irq+0xc63/0x2080 kernel/rcu/tree.c:2649

stack backtrace:
CPU: 1 PID: 25710 Comm: syz-executor.1 Not tainted 5.13.0-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+0x141/0x1d7 lib/dump_stack.c:120
 print_usage_bug kernel/locking/lockdep.c:203 [inline]
 valid_state kernel/locking/lockdep.c:3820 [inline]
 mark_lock_irq kernel/locking/lockdep.c:4023 [inline]
 mark_lock.cold+0x61/0x8e kernel/locking/lockdep.c:4480
 mark_held_locks+0x9f/0xe0 kernel/locking/lockdep.c:4081
 __trace_hardirqs_on_caller kernel/locking/lockdep.c:4099 [inline]
 lockdep_hardirqs_on_prepare kernel/locking/lockdep.c:4167 [inline]
 lockdep_hardirqs_on_prepare+0x135/0x400 kernel/locking/lockdep.c:4119
 trace_hardirqs_on+0x5b/0x1c0 kernel/trace/trace_preemptirq.c:49
 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:647
RIP: 0010:lock_acquire+0x1ef/0x740 kernel/locking/lockdep.c:5480
Code: 72 a7 7e 83 f8 01 0f 85 ee 03 00 00 9c 58 f6 c4 02 0f 85 d9 03 00 00 48 83 7c 24 08 00 74 01 fb 48 b8 00 00 00 00 00 fc ff df <48> 01 c3 48 c7 03 00 00 00 00 48 c7 43 08 00 00 00 00 48 8b 84 24
RSP: 0018:ffffc90000dc0d50 EFLAGS: 00000206
RAX: dffffc0000000000 RBX: 1ffff920001b81ac RCX: 00000000ef951384
RDX: 1ffff11011ebc13e RSI: 0000000000000101 RDI: 0000000000000000
RBP: 0000000000000000 R08: 0000000000000000 R09: ffffffff902288a7
R10: fffffbfff2045114 R11: 0000000000000001 R12: 0000000000000002
R13: ffffffff8bf79620 R14: 0000000000000000 R15: 0000000000000000
 rcu_lock_acquire include/linux/rcupdate.h:267 [inline]
 rcu_read_lock include/linux/rcupdate.h:657 [inline]
 ieee80211_rx_napi+0xaa/0x3d0 net/mac80211/rx.c:4923
 ieee80211_rx include/net/mac80211.h:4528 [inline]
 ieee80211_tasklet_handler+0xd4/0x130 net/mac80211/main.c:235
 tasklet_action_common.constprop.0+0x201/0x2e0 kernel/softirq.c:784
 __do_softirq+0x29b/0x9f6 kernel/softirq.c:559
 invoke_softirq kernel/softirq.c:433 [inline]
 __irq_exit_rcu+0x136/0x200 kernel/softirq.c:637
 irq_exit_rcu+0x5/0x20 kernel/softirq.c:649
 sysvec_apic_timer_interrupt+0x93/0xc0 arch/x86/kernel/apic/apic.c:1100
 </IRQ>
 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:647
RIP: 0010:preempt_schedule_irq+0x49/0x90 kernel/sched/core.c:5535
Code: 55 53 65 48 8b 1c 25 00 f0 01 00 48 89 dd 48 c1 ed 03 48 01 c5 bf 01 00 00 00 e8 22 6f 36 f8 e8 dd 58 62 f8 fb bf 01 00 00 00 <e8> 92 ce ff ff 9c 58 fa f6 c4 02 75 27 bf 01 00 00 00 e8 70 5d 36
RSP: 0018:ffffc90003c57798 EFLAGS: 00000206
RAX: 000000000028045f RBX: ffff88808f5e0000 RCX: 1ffffffff20478d2
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000001
RBP: ffffed1011ebc000 R08: 0000000000000001 R09: ffffffff902288d7
R10: 0000000000000001 R11: 0000000000000001 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
 irqentry_exit+0x31/0x80 kernel/entry/common.c:427
 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:647
RIP: 0010:__slab_alloc.constprop.0+0x68/0xf0 mm/slub.c:2801
Code: 0e 8b 4c 89 f9 44 89 f2 44 89 ee 48 89 ef 4d 01 e0 e8 1c f4 ff ff 49 89 c4 9c 58 f6 c4 02 75 53 48 85 db 74 01 fb 48 83 c4 08 <4c> 89 e0 5b 5d 41 5c 41 5d 41 5e 41 5f c3 e8 75 59 c1 ff 4c 8b 65
RSP: 0018:ffffc90003c57868 EFLAGS: 00000282
RAX: 0000000000000002 RBX: 0000000000000200 RCX: 1ffffffff20478d2
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: ffff888011042140 R08: 0000000000000001 R09: ffffffff902288d7
R10: 0000000000000001 R11: 0000000000000000 R12: ffff88806f060000
R13: 0000000000000dc0 R14: 00000000ffffffff R15: ffffffff87038920
 slab_alloc_node mm/slub.c:2880 [inline]
 slab_alloc mm/slub.c:2922 [inline]
 __kmalloc+0x315/0x330 mm/slub.c:4050
 kmalloc include/linux/slab.h:561 [inline]
 sk_prot_alloc+0x110/0x290 net/core/sock.c:1711
 sk_alloc+0x32/0xbd0 net/core/sock.c:1764
 tun_chr_open+0x7b/0x540 drivers/net/tun.c:3361
 misc_open+0x372/0x4a0 drivers/char/misc.c:141
 chrdev_open+0x266/0x770 fs/char_dev.c:414
 do_dentry_open+0x4b9/0x11b0 fs/open.c:826
 do_open fs/namei.c:3361 [inline]
 path_openat+0x1c0e/0x27e0 fs/namei.c:3494
 do_filp_open+0x190/0x3d0 fs/namei.c:3521
 do_sys_openat2+0x16d/0x420 fs/open.c:1187
 do_sys_open fs/open.c:1203 [inline]
 __do_sys_openat fs/open.c:1219 [inline]
 __se_sys_openat fs/open.c:1214 [inline]
 __x64_sys_openat+0x13f/0x1f0 fs/open.c:1214
 do_syscall_64+0x3a/0xb0 arch/x86/entry/common.c:47
 entry_SYSCALL_64_after_hwframe+0x44/0xae
RIP: 0033:0x4665d9
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 bc ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f3a80a16188 EFLAGS: 00000246 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 000000000056bf80 RCX: 00000000004665d9
RDX: 0000000000000000 RSI: 0000000020000040 RDI: ffffffffffffff9c
RBP: 00000000004bfcb9 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 000000000056bf80
R13: 00007ffc338ba8ef R14: 00007f3a80a16300 R15: 0000000000022000
softirq: huh, entered softirq 6 TASKLET ffffffff8145dc00 with preempt_count 00000101, exited with 00000102?