rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	1-...!: (1 GPs behind) idle=edcc/1/0x4000000000000000 softirq=52392/52393 fqs=0
rcu: 	(detected by 0, t=10506 jiffies, g=44365, q=4148 ncpus=2)
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 12817 Comm: syz.5.1786 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:do_raw_spin_unlock+0xd2/0x240
Code: 84 c0 0f 85 42 01 00 00 41 8b 07 65 8b 0d ba 97 02 11 39 c8 0f 85 d4 00 00 00 43 80 7c 25 00 00 74 08 4c 89 f7 e8 6e 33 85 00 <49> c7 06 ff ff ff ff 42 0f b6 44 25 00 84 c0 0f 85 29 01 00 00 41
RSP: 0018:ffffc900001e0848 EFLAGS: 00000046
RAX: 0000000000000001 RBX: ffff888136627a80 RCX: 0000000000000001
RDX: 0000000000000000 RSI: 0000000000000004 RDI: ffff888136627a80
RBP: 1ffff11026cc4f51 R08: ffff888136627a83 R09: 1ffff11026cc4f50
R10: dffffc0000000000 R11: ffffed1026cc4f51 R12: dffffc0000000000
R13: 1ffff11026cc4f52 R14: ffff888136627a90 R15: ffff888136627a88
FS:  00007f595909e6c0(0000) GS:ffff8881a3c15000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000110c2803c8 CR3: 000000012e91c000 CR4: 00000000000006f0
DR0: 0000200000000300 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600
Call Trace:
 <IRQ>
 _raw_spin_unlock_irqrestore+0x78/0x110
 hrtimer_try_to_cancel+0x3be/0x420
 hrtimer_cancel+0x3b/0x50
 cpu_clock_event_stop+0xd9/0x130
 __perf_event_overflow+0x580/0xe40
 perf_swevent_hrtimer+0x3c5/0x550
 __hrtimer_run_queues+0x4e0/0xc60
 hrtimer_interrupt+0x45b/0xaa0
 __sysvec_apic_timer_interrupt+0x10b/0x410
 sysvec_apic_timer_interrupt+0xa1/0xc0
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x1a/0x20
RIP: 0010:preempt_schedule_irq+0xb0/0x150
Code: 24 20 f6 44 24 21 02 74 0c 90 0f 0b 48 f7 03 08 00 00 00 74 64 bf 01 00 00 00 e8 ab 7a 14 f6 e8 16 d7 4b f6 fb bf 01 00 00 00 <e8> 5b ab ff ff 48 c7 44 24 40 00 00 00 00 9c 8f 44 24 40 8b 44 24
RSP: 0018:ffffc90007f573e0 EFLAGS: 00000282
RAX: 12c1f05ff9b9a300 RBX: 0000000000000000 RCX: 12c1f05ff9b9a300
RDX: 0000000000000007 RSI: ffffffff8d9ba18b RDI: 0000000000000001
RBP: ffffc90007f57480 R08: ffffffff8fa3a837 R09: 1ffffffff1f47506
R10: dffffc0000000000 R11: fffffbfff1f47507 R12: 0000000000000000
R13: 0000000000000000 R14: dffffc0000000000 R15: 1ffff92000feae7c
 irqentry_exit+0x6f/0x90
 asm_sysvec_call_function_single+0x1a/0x20
RIP: 0010:__slab_free+0x251/0x3c0
Code: ea 48 8b 4c 24 10 4d 89 f8 e8 1b e1 ff ff 41 89 c7 e9 44 fe ff ff 48 8b 5c 24 10 4c 89 f9 4c 89 e0 4c 89 ea f0 48 0f c7 4e 20 <0f> 85 95 fe ff ff 48 85 ed 75 2c 45 85 ed 79 57 65 48 8b 05 27 ae
RSP: 0018:ffffc90007f57548 EFLAGS: 00000242
RAX: 0000000000000000 RBX: ffff888124d5e000 RCX: 0000000000040003
RDX: 0000000000040004 RSI: ffffea0004935600 RDI: 0000000000000000
RBP: 0000000000000000 R08: 0000000000000001 R09: 0000000000000000
R10: dffffc0000000000 R11: fffffbfff1f47507 R12: 0000000000000000
R13: 0000000000040004 R14: ffff88801a442140 R15: 0000000000040003
 qlist_free_all+0x97/0x140
 kasan_quarantine_reduce+0x148/0x160
 __kasan_slab_alloc+0x22/0x80
 __kmalloc_noprof+0x224/0x4f0
 sk_prot_alloc+0xe7/0x220
 sk_alloc+0x3a/0x370
 tun_chr_open+0x7a/0x510
 misc_open+0x2bc/0x330
 chrdev_open+0x4cc/0x5e0
 do_dentry_open+0x953/0x13f0
 vfs_open+0x3b/0x340
 path_openat+0x2ee5/0x3830
 do_filp_open+0x1fa/0x410
 do_sys_openat2+0x121/0x1c0
 __x64_sys_openat+0x138/0x170
 do_syscall_64+0xfa/0x3b0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f595818eba9
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 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f595909e038 EFLAGS: 00000246 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 00007f59583d5fa0 RCX: 00007f595818eba9
RDX: 0000000000080001 RSI: 0000200000000040 RDI: ffffffffffffff9c
RBP: 00007f5958211e19 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f59583d6038 R14: 00007f59583d5fa0 R15: 00007fffcc429008
 </TASK>
rcu: rcu_preempt kthread starved for 10506 jiffies! g44365 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=0
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:27160 pid:16    tgid:16    ppid:2      task_flags:0x208040 flags:0x00004000
Call Trace:
 <TASK>
 __schedule+0x1798/0x4cc0
 schedule+0x165/0x360
 schedule_timeout+0x12b/0x270
 rcu_gp_fqs_loop+0x301/0x1540
 rcu_gp_kthread+0x99/0x390
 kthread+0x711/0x8a0
 ret_from_fork+0x439/0x7d0
 ret_from_fork_asm+0x1a/0x30
 </TASK>
rcu: Stack dump where RCU GP kthread last ran:
CPU: 0 UID: 0 PID: 12820 Comm: syz.6.1787 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:smp_call_function_many_cond+0xd33/0x12d0
Code: 45 8b 2c 24 44 89 ee 83 e6 01 31 ff e8 56 63 0b 00 41 83 e5 01 49 bd 00 00 00 00 00 fc ff df 75 07 e8 01 5f 0b 00 eb 38 f3 90 <42> 0f b6 04 2b 84 c0 75 11 41 f7 04 24 01 00 00 00 74 1e e8 e5 5e
RSP: 0018:ffffc90007ec7480 EFLAGS: 00000293
RAX: ffffffff81b4621b RBX: 1ffff11026cc7f61 RCX: ffff88801f9e5640
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000
RBP: ffffc90007ec7600 R08: ffff88811084e007 R09: 1ffff11022109c00
R10: dffffc0000000000 R11: ffffed1022109c01 R12: ffff88813663fb08
R13: dffffc0000000000 R14: ffff88804b03b1c0 R15: 0000000000000001
FS:  00007fc7075576c0(0000) GS:ffff8880b8615000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00005555691a75c8 CR3: 0000000108adc000 CR4: 00000000000006f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600
Call Trace:
 <TASK>
 on_each_cpu_cond_mask+0x3f/0x80
 flush_tlb_mm_range+0x6b1/0x12d0
 tlb_flush_mmu+0x1a7/0x680
 tlb_finish_mmu+0xc3/0x1d0
 exit_mmap+0x44c/0xb50
 __mmput+0x118/0x430
 exit_mm+0x1da/0x2c0
 do_exit+0x648/0x2300
 do_group_exit+0x21c/0x2d0
 get_signal+0x1286/0x1340
 arch_do_signal_or_restart+0x9a/0x750
 exit_to_user_mode_loop+0x75/0x110
 do_syscall_64+0x2bd/0x3b0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fc70678eba9
Code: Unable to access opcode bytes at 0x7fc70678eb7f.
RSP: 002b:00007fc7075570e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca
RAX: fffffffffffffe00 RBX: 00007fc7069d6098 RCX: 00007fc70678eba9
RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007fc7069d6098
RBP: 00007fc7069d6090 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fc7069d6128 R14: 00007ffc3ecf6c10 R15: 00007ffc3ecf6cf8
 </TASK>
