general protection fault in vcpu_enter_guest

[syzbot]

Hello,

syzbot found the following crash on:

HEAD commit:    4110b42356f3 Add linux-next specific files for 20180810
git tree:       linux-next
console output: https://syzkaller.appspot.com/x/log.txt?x=158a6f54400000
kernel config:  https://syzkaller.appspot.com/x/.config?x=1d80606e3795a4f5
dashboard link: https://syzkaller.appspot.com/bug?extid=a7d2d21d5cbb86bfd129
compiler:       gcc (GCC) 8.0.1 20180413 (experimental)

Unfortunately, I don't have any reproducer for this crash yet.

IMPORTANT: if you fix the bug, please add the following tag to the commit:
Reported-by: syzbot+a7d2d21d5cbb86bfd129@xxxxxxxxxxxxxxxxxxxxxxxxx

kasan: CONFIG_KASAN_INLINE enabled
kasan: GPF could be caused by NULL-ptr deref or user memory access
general protection fault: 0000 [#1] SMP KASAN
CPU: 1 PID: 12684 Comm: syz-executor6 Not tainted 4.18.0-rc8-next-20180810+  
#36
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS  
Google 01/01/2011
RIP: 0010:kvm_apic_hw_enabled arch/x86/kvm/lapic.h:169 [inline]
RIP: 0010:vcpu_scan_ioapic arch/x86/kvm/x86.c:7243 [inline]
RIP: 0010:vcpu_enter_guest+0x51f9/0x6360 arch/x86/kvm/x86.c:7389
Code: 80 3c 02 00 0f 85 79 11 00 00 4c 8b a3 e0 03 00 00 48 b8 00 00 00 00  
00 fc ff df 49 8d bc 24 88 00 00 00 48 89 fa 48 c1 ea 03 <80> 3c 02 00 0f  
85 45 11 00 00 4d 8b a4 24 88 00 00 00 48 b8 00 00
RSP: 0018:ffff88019465f4f0 EFLAGS: 00010206
RAX: dffffc0000000000 RBX: ffff88018fb40200 RCX: ffffc90004417000
RDX: 0000000000000011 RSI: ffffffff810eb6b7 RDI: 0000000000000088
RBP: ffff88019465f840 R08: ffff8801b2b2c6c0 R09: 0000000000000001
R10: ffff88019465f860 R11: 97ac495aab52485c R12: 0000000000000000
R13: 0000000002814001 R14: dffffc0000000000 R15: ffff88018fb40230
FS:  00007f75b27a9700(0000) GS:ffff8801db100000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000001b8e7d0 CR3: 00000001aebfc000 CR4: 00000000001426e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 vcpu_run arch/x86/kvm/x86.c:7660 [inline]
 kvm_arch_vcpu_ioctl_run+0x33e/0x1690 arch/x86/kvm/x86.c:7837
 kvm_vcpu_ioctl+0x7b8/0x1300 arch/x86/kvm/../../../virt/kvm/kvm_main.c:2590
 vfs_ioctl fs/ioctl.c:46 [inline]
 file_ioctl fs/ioctl.c:501 [inline]
 do_vfs_ioctl+0x1de/0x1720 fs/ioctl.c:685
 ksys_ioctl+0xa9/0xd0 fs/ioctl.c:702
 __do_sys_ioctl fs/ioctl.c:709 [inline]
 __se_sys_ioctl fs/ioctl.c:707 [inline]
 __x64_sys_ioctl+0x73/0xb0 fs/ioctl.c:707
 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x457089
Code: fd b4 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 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 0f 83 cb b4 fb ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007f75b27a8c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007f75b27a96d4 RCX: 0000000000457089
RDX: 0000000000000000 RSI: 000000000000ae80 RDI: 0000000000000006
RBP: 00000000009300a0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff
R13: 00000000004ceb90 R14: 00000000004c54c9 R15: 0000000000000000
Modules linked in:
Dumping ftrace buffer:
   (ftrace buffer empty)
---[ end trace e6eaa75019e681cb ]---
RIP: 0010:kvm_apic_hw_enabled arch/x86/kvm/lapic.h:169 [inline]
RIP: 0010:vcpu_scan_ioapic arch/x86/kvm/x86.c:7243 [inline]
RIP: 0010:vcpu_enter_guest+0x51f9/0x6360 arch/x86/kvm/x86.c:7389
Code: 80 3c 02 00 0f 85 79 11 00 00 4c 8b a3 e0 03 00 00 48 b8 00 00 00 00  
00 fc ff df 49 8d bc 24 88 00 00 00 48 89 fa 48 c1 ea 03 <80> 3c 02 00 0f  
85 45 11 00 00 4d 8b a4 24 88 00 00 00 48 b8 00 00
RSP: 0018:ffff88019465f4f0 EFLAGS: 00010206
RAX: dffffc0000000000 RBX: ffff88018fb40200 RCX: ffffc90004417000
RDX: 0000000000000011 RSI: ffffffff810eb6b7 RDI: 0000000000000088
RBP: ffff88019465f840 R08: ffff8801b2b2c6c0 R09: 0000000000000001
R10: ffff88019465f860 R11: 97ac495aab52485c R12: 0000000000000000
netlink: 28 bytes leftover after parsing attributes in process  
`syz-executor5'.
R13: 0000000002814001 R14: dffffc0000000000 R15: ffff88018fb40230
FS:  00007f75b27a9700(0000) GS:ffff8801db100000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000001b8e7d0 CR3: 00000001aebfc000 CR4: 00000000001426e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
IPVS: set_ctl: invalid protocol: 59 172.20.20.20:20003
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400


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