general protection fault in vmx_vcpu_run

[syzbot]

Hello,

syzbot hit the following crash on upstream commit
b284d4d5a6785f8cd07eda2646a95782373cd01e (Tue Apr 10 19:25:30 2018 +0000)
Merge tag 'ceph-for-4.17-rc1' of git://github.com/ceph/ceph-client
syzbot dashboard link:  
https://syzkaller.appspot.com/bug?extid=cc483201a3c6436d3550

So far this crash happened 2 times on upstream.
Unfortunately, I don't have any reproducer for this crash yet.
Raw console output:  
https://syzkaller.appspot.com/x/log.txt?id=5622460745515008
Kernel config:  
https://syzkaller.appspot.com/x/.config?id=-1223000601505858474
compiler: gcc (GCC) 8.0.1 20180301 (experimental)

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Reported-by: syzbot+cc483201a3c6436d3550@xxxxxxxxxxxxxxxxxxxxxxxxx
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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
Dumping ftrace buffer:
   (ftrace buffer empty)
Modules linked in:
CPU: 1 PID: 6155 Comm: syz-executor1 Not tainted 4.16.0+ #19
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS  
Google 01/01/2011
RIP: 0010:vmx_vcpu_run+0x95f/0x25f0 arch/x86/kvm/vmx.c:9746
RSP: 0018:ffff8801ac217368 EFLAGS: 00010002
RAX: ffffed003725a3a0 RBX: ffff8801c751ab00 RCX: 1ffff10035842e78
RDX: 0000000000000001 RSI: 0000000000000004 RDI: ffff8801b92d1cf8
RBP: ffff8801db107a18 R08: ffffed003725a3a0 R09: ffffed003725a39f
R10: ffffed003725a39f R11: ffff8801b92d1cfb R12: ffff8801b92d1c20
R13: 1ffff1003b620f2a R14: ffff8801d7448300 R15: ffff8801c751ab90
FS:  00007f47f8675700(0000) GS:ffff8801db100000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000000 CR3: 00000001b0d04000 CR4: 00000000001426e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 save_stack+0xa9/0xd0 mm/kasan/kasan.c:454
 set_track mm/kasan/kasan.c:460 [inline]
 kasan_kmalloc+0xc4/0xe0 mm/kasan/kasan.c:553
 kasan_slab_alloc+0x12/0x20 mm/kasan/kasan.c:490
 slab_post_alloc_hook mm/slab.h:444 [inline]
 slab_alloc mm/slab.c:3392 [inline]
 kmem_cache_alloc+0x11b/0x760 mm/slab.c:3552
 getname_flags+0xd0/0x5a0 fs/namei.c:140
 getname+0x19/0x20 fs/namei.c:211
 do_sys_open+0x38e/0x770 fs/open.c:1087
 SYSC_openat fs/open.c:1120 [inline]
 SyS_openat+0x30/0x40 fs/open.c:1114
 do_syscall_64+0x29e/0x9d0 arch/x86/entry/common.c:287
 entry_SYSCALL_64_after_hwframe+0x42/0xb7
RIP: 0033:0x455259
RSP: 002b:00007f47f8674c68 EFLAGS: 00000246 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 00007f47f86756d4 RCX: 0000000000455259
RDX: 0000000000000000 RSI: 00000000200001c0 RDI: ffffffffffffff9c
RBP: 000000000072bea0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff
R13: 000000000000042f R14: 00000000006f9508 R15: 0000000000000000
Code: 8b a9 68 03 00 00 4c 8b b1 70 03 00 00 4c 8b b9 78 03 00 00 48 8b 89  
08 03 00 00 75 05 0f 01 c2 eb 03 0f 01 c3 48 89 4c 24 08 59 <0f> 96 81 88  
56 00 00 48 89 81 00 03 00 00 48 89 99 18 03 00 00
RIP: vmx_vcpu_run+0x95f/0x25f0 arch/x86/kvm/vmx.c:9746 RSP: ffff8801ac217368
---[ end trace c157ab9734a00941 ]---


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