rcu: INFO: rcu_preempt self-detected stall on CPU
rcu: 	1-...!: (1 ticks this GP) idle=37dc/1/0x4000000000000000 softirq=47274/47274 fqs=0
rcu: 	(t=29440 jiffies g=36901 q=206 ncpus=2)
rcu: rcu_preempt kthread starved for 29440 jiffies! g36901 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:27536 pid:16    tgid:16    ppid:2      task_flags:0x208040 flags:0x00080000
Call Trace:
 <TASK>
 __schedule+0x1821/0x5740
 schedule+0x164/0x360
 schedule_timeout+0x158/0x2c0
 rcu_gp_fqs_loop+0x312/0x11d0
 rcu_gp_kthread+0x9e/0x2b0
 kthread+0x388/0x470
 ret_from_fork+0x514/0xb70
 ret_from_fork_asm+0x1a/0x30
 </TASK>
rcu: Stack dump where RCU GP kthread last ran:
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 7352 Comm: udevd 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+0xfcf/0x13d0
Code: 79 45 8b 2e 44 89 ee 83 e6 01 31 ff e8 da 07 0c 00 41 83 e5 01 49 bd 00 00 00 00 00 fc ff df 75 07 e8 85 03 0c 00 eb 37 f3 90 <43> 0f b6 04 2c 84 c0 75 10 41 f7 06 01 00 00 00 74 1e e8 6a 03 0c
RSP: 0000:ffffc90007b5f760 EFLAGS: 00000293
RAX: ffffffff81b9be66 RBX: ffff88812103c148 RCX: ffff8881738e0000
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000
RBP: ffffc90007b5f8a0 R08: ffffffff9030b6f7 R09: 1ffffffff20616de
R10: dffffc0000000000 R11: fffffbfff20616df R12: 1ffff110478c8169
R13: dffffc0000000000 R14: ffff88823c640b48 R15: 0000000000000001
FS:  00007f53332a3280(0000) GS:ffff88818dc8d000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055997a2736d8 CR3: 00000001b8a74000 CR4: 0000000000352ef0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 000000000000007a
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 on_each_cpu_cond_mask+0x3f/0x80
 kvm_flush_tlb_multi+0x2b4/0x320
 flush_tlb_mm_range+0x5c3/0x10b0
 ptep_clear_flush+0x120/0x170
 do_wp_page+0x3da7/0x4cc0
 handle_mm_fault+0x151d/0x3170
 do_user_addr_fault+0xa73/0x1340
 exc_page_fault+0x6a/0xc0
 asm_exc_page_fault+0x26/0x30
RIP: 0033:0x7f5332ec742d
Code: c2 0f 85 f9 fc ff ff 48 89 ef e8 78 f5 ff ff 4d 39 6e 60 74 6e 43 f6 44 25 08 01 75 0d 4c 89 ef 4c 01 e3 e8 5f f5 ff ff eb 05 <49> 83 65 08 fe 49 8b 46 70 49 8d 56 60 48 8d 3d 72 e5 0e 00 48 39
RSP: 002b:00007ffecaaa2430 EFLAGS: 00010202
RAX: 0000000000000080 RBX: 0000000000006090 RCX: 0000000000000081
RDX: 00007f5332ff1b70 RSI: 000055997a26c010 RDI: 000055997a26d640
RBP: 000055997a26d640 R08: 0000000000000000 R09: 0d66e25809881d9e
R10: 00000000ffffffff R11: 0000000000000246 R12: 00000000000001d0
R13: 000055997a2736d0 R14: 00007f5332ff1aa0 R15: 000055997a26c910
 </TASK>
CPU: 1 UID: 0 PID: 8790 Comm: syz.3.849 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:vcpu_run+0x5a02/0x7860
Code: 4c 8b a4 24 28 01 00 00 4c 89 e3 48 c1 eb 03 42 0f b6 04 3b 84 c0 0f 85 1c 0b 00 00 41 c6 04 24 01 e8 02 eb 85 00 fb 4c 89 f0 <48> c1 e8 03 42 80 3c 38 00 74 08 4c 89 f7 e8 2b fd e8 00 49 ff 06
RSP: 0018:ffffc900033b75e0 EFLAGS: 00000202
RAX: ffff8881b3f5c720 RBX: 1ffff110367eb6bf RCX: 0000000080000001
RDX: 0000000000000006 RSI: ffffffff8dfa6837 RDI: ffffffff8c28af60
RBP: ffffc900033b79b0 R08: ffffffff9030b6f7 R09: 1ffffffff20616de
R10: dffffc0000000000 R11: fffffbfff20616df R12: ffff8881b3f5b5fa
R13: ffff8881b3f5a9c0 R14: ffff8881b3f5c720 R15: dffffc0000000000
FS:  00007efd58db26c0(0000) GS:ffff8882a928d000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000000 CR3: 0000000177768000 CR4: 0000000000352ef0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 000000000000007a
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 kvm_arch_vcpu_ioctl_run+0x11e6/0x20d0
 kvm_vcpu_ioctl+0xa62/0xfd0
 __se_sys_ioctl+0xfc/0x170
 do_syscall_64+0x15f/0xf80
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7efd57f9cdd9
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 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 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007efd58db2028 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007efd58215fa0 RCX: 00007efd57f9cdd9
RDX: 0000000000000000 RSI: 000000000000ae80 RDI: 0000000000000006
RBP: 00007efd58032d69 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007efd58216038 R14: 00007efd58215fa0 R15: 00007fffc152cc68
 </TASK>
