Message-ID: <001a113e8a28d9ae59055cd80de6@google.com>
Date:   Tue, 31 Oct 2017 06:51:38 -0700
From:   syzbot 
        <bot+53e9b911da5806836ed78f23e2b8ead1c905b469@...kaller.appspotmail.com>
To:     hpa@...or.com, kvm@...r.kernel.org, linux-kernel@...r.kernel.org,
        mingo@...hat.com, pbonzini@...hat.com, rkrcmar@...hat.com,
        syzkaller-bugs@...glegroups.com, tglx@...utronix.de, x86@...nel.org
Subject: general protection fault in gfn_to_rmap

Hello,

syzkaller hit the following crash on  
0b5477d9dabd96ded4c5ef7a5f08b00188fc1dec
git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/master
compiler: gcc (GCC) 7.1.1 20170620
.config is attached
Raw console output is attached.

syzkaller reproducer is attached. See https://goo.gl/kgGztJ
for information about syzkaller reproducers


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: 0 PID: 4407 Comm: syz-executor5 Not tainted 4.13.0-rc2+ #9
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS  
Google 01/01/2011
task: ffff8801d661c0c0 task.stack: ffff8801ca9b0000
RIP: 0010:__kvm_memslots include/linux/kvm_host.h:571 [inline]
RIP: 0010:gfn_to_rmap+0x57f/0x6b0 arch/x86/kvm/mmu.c:1235
RSP: 0018:ffff8801ca9b6820 EFLAGS: 00010297
RAX: dffffc0000000000 RBX: ffff8801cc3e1078 RCX: 1ffff1003987c204
RDX: 0000000000000000 RSI: ffff8801cc3ec3c8 RDI: ffff8801cc3e1080
RBP: ffff8801ca9b6960 R08: 0000000000000002 R09: 0000000000000004
R10: ffff8801ca9b6cc8 R11: ffffffff81120ef1 R12: 0000000000000002
R13: 000000000000000f R14: 000000000000000e R15: dffffc0000000000
FS:  0000000000000000(0000) GS:ffff8801dc000000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000000 CR3: 00000001d28ce000 CR4: 00000000001426f0
Call Trace:
  rmap_remove arch/x86/kvm/mmu.c:1267 [inline]
  drop_spte+0x161/0x270 arch/x86/kvm/mmu.c:1350
  mmu_page_zap_pte+0x224/0x350 arch/x86/kvm/mmu.c:2482
  kvm_mmu_page_unlink_children arch/x86/kvm/mmu.c:2504 [inline]
  kvm_mmu_prepare_zap_page+0x1b7/0x1260 arch/x86/kvm/mmu.c:2548
  kvm_zap_obsolete_pages arch/x86/kvm/mmu.c:5223 [inline]
  kvm_mmu_invalidate_zap_all_pages+0x4a0/0x680 arch/x86/kvm/mmu.c:5264
  kvm_arch_flush_shadow_all+0x15/0x20 arch/x86/kvm/x86.c:8394
  kvm_mmu_notifier_release+0x59/0x90  
arch/x86/kvm/../../../virt/kvm/kvm_main.c:508
  __mmu_notifier_release+0x1d5/0x690 mm/mmu_notifier.c:75
  mmu_notifier_release include/linux/mmu_notifier.h:235 [inline]
  exit_mmap+0x3a3/0x470 mm/mmap.c:2972
  __mmput kernel/fork.c:903 [inline]
  mmput+0x223/0x6e0 kernel/fork.c:925
  exit_mm kernel/exit.c:544 [inline]
  do_exit+0x981/0x1b10 kernel/exit.c:852
  do_group_exit+0x149/0x400 kernel/exit.c:969
  get_signal+0x7e8/0x17e0 kernel/signal.c:2330
  do_signal+0x94/0x1ee0 arch/x86/kernel/signal.c:808
  exit_to_usermode_loop+0x21c/0x2d0 arch/x86/entry/common.c:157
  prepare_exit_to_usermode arch/x86/entry/common.c:194 [inline]
  syscall_return_slowpath+0x3a7/0x450 arch/x86/entry/common.c:263
  entry_SYSCALL_64_fastpath+0xbc/0xbe
RIP: 0033:0x4512c9
RSP: 002b:00007f5548015c18 EFLAGS: 00000206 ORIG_RAX: 00000000000000ca
RAX: 0000000000000001 RBX: 00000000007180a8 RCX: 00000000004512c9
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 00000000007180cc
RBP: 0000000000001fe0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000206 R12: 00000000004b7f09
R13: 00000000ffffffff R14: 0000000000000007 R15: 000000000000ae80
Code: 3c 02 00 00 48 c7 c7 20 63 62 84 c6 05 e0 42 f8 03 01 e8 25 de 44 00  
e9 da fb ff ff e8 6b 7f 5d 00 48 b8 00 00 00 00 00 fc ff df <80> 38 00 0f  
85 1b 01 00 00 4c 8b 24 25 00 00 00 00 31 db e9 83
RIP: __kvm_memslots include/linux/kvm_host.h:571 [inline] RSP:  
ffff8801ca9b6820
RIP: gfn_to_rmap+0x57f/0x6b0 arch/x86/kvm/mmu.c:1235 RSP: ffff8801ca9b6820
---[ end trace 0a16957bec756c04 ]---


---
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See https://goo.gl/tpsmEJ for details.
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