general protection fault in kvm_arch_vcpu_ioctl_run

syzbot
2018-12-04T07:16:02Z

Hello,

syzbot found the following crash on:

HEAD commit: 4b78317679c4 Merge branch 'x86-pti-for-linus' of git://git..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=15e979f5400000
kernel config: https://syzkaller.appspot.com/x/.config?x=4602730af4f872ef
dashboard link: https://syzkaller.appspot.com/bug?extid=39810e6c400efadfef71
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+39810e6c400efadfef71@syzkaller.appspotmail.com

kasan: GPF could be caused by NULL-ptr deref or user memory access
general protection fault: 0000 [#1] PREEMPT SMP KASAN
CPU: 0 PID: 14932 Comm: syz-executor0 Not tainted 4.20.0-rc4+ #138
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:7449 [inline]
RIP: 0010:vcpu_enter_guest arch/x86/kvm/x86.c:7602 [inline]
RIP: 0010:vcpu_run arch/x86/kvm/x86.c:7874 [inline]
RIP: 0010:kvm_arch_vcpu_ioctl_run+0x5296/0x7320 arch/x86/kvm/x86.c:8074
Code: 03 00 00 48 89 f8 48 c1 e8 03 42 80 3c 20 00 0f 85 b4 1e 00 00 49 8b
9f e0 03 00 00 48 8d bb 88 00 00 00 48 89 f8 48 c1 e8 03 <42> 80 3c 20 00
0f 85 8a 1e 00 00 48 8b 9b 88 00 00 00 48 8d bb d8
RSP: 0018:ffff88818b0bf530 EFLAGS: 00010206
RAX: 0000000000000011 RBX: 0000000000000000 RCX: ffffc9001302b000
RDX: 00000000000000cf RSI: ffffffff81103a68 RDI: 0000000000000088
RBP: ffff88818b0bf8d0 R08: ffff8881bfe8e0c0 R09: 0000000000000008
R10: 0000000000000028 R11: ffffffff810feb0f R12: dffffc0000000000
R13: 0000000000000000 R14: ffffc90007ddfdb8 R15: ffff888188a18400
FS: 00007ff919977700(0000) GS:ffff8881dae00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fc94713c518 CR3: 00000001cdea0000 CR4: 00000000001426f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
kvm_vcpu_ioctl+0x5c8/0x1150 arch/x86/kvm/../../../virt/kvm/kvm_main.c:2596
vfs_ioctl fs/ioctl.c:46 [inline]
file_ioctl fs/ioctl.c:509 [inline]
do_vfs_ioctl+0x1de/0x1790 fs/ioctl.c:696
ksys_ioctl+0xa9/0xd0 fs/ioctl.c:713
__do_sys_ioctl fs/ioctl.c:720 [inline]
__se_sys_ioctl fs/ioctl.c:718 [inline]
__x64_sys_ioctl+0x73/0xb0 fs/ioctl.c:718
do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290
entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x457569
Code: fd b3 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 b3 fb ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007ff919976c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000000457569
RDX: 0000000000000000 RSI: 000000000000ae80 RDI: 0000000000000005
RBP: 000000000072bf00 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007ff9199776d4
R13: 00000000004c034e R14: 00000000004d0d60 R15: 00000000ffffffff
Modules linked in:
kobject: 'loop5' (000000004f26f0d5): kobject_uevent_env
kobject: 'loop5' (000000004f26f0d5): fill_kobj_path: path
= '/devices/virtual/block/loop5'
kobject: 'loop1' (0000000010db8550): kobject_uevent_env
kobject: 'loop1' (0000000010db8550): fill_kobj_path: path
= '/devices/virtual/block/loop1'
kobject: 'loop3' (00000000941a4e7a): kobject_uevent_env
kobject: 'loop3' (00000000941a4e7a): fill_kobj_path: path
= '/devices/virtual/block/loop3'
---[ end trace d7fab4e7c1a70214 ]---
RIP: 0010:kvm_apic_hw_enabled arch/x86/kvm/lapic.h:169 [inline]
RIP: 0010:vcpu_scan_ioapic arch/x86/kvm/x86.c:7449 [inline]
RIP: 0010:vcpu_enter_guest arch/x86/kvm/x86.c:7602 [inline]
RIP: 0010:vcpu_run arch/x86/kvm/x86.c:7874 [inline]
RIP: 0010:kvm_arch_vcpu_ioctl_run+0x5296/0x7320 arch/x86/kvm/x86.c:8074
Code: 03 00 00 48 89 f8 48 c1 e8 03 42 80 3c 20 00 0f 85 b4 1e 00 00 49 8b
9f e0 03 00 00 48 8d bb 88 00 00 00 48 89 f8 48 c1 e8 03 <42> 80 3c 20 00
0f 85 8a 1e 00 00 48 8b 9b 88 00 00 00 48 8d bb d8
kobject: 'loop4' (000000004a89aba1): kobject_uevent_env
kobject: 'loop4' (000000004a89aba1): fill_kobj_path: path
= '/devices/virtual/block/loop4'
kobject: 'loop2' (00000000704d7e59): kobject_uevent_env
kobject: 'loop2' (00000000704d7e59): fill_kobj_path: path
= '/devices/virtual/block/loop2'
kobject: 'loop4' (000000004a89aba1): kobject_uevent_env
kobject: 'loop4' (000000004a89aba1): fill_kobj_path: path
= '/devices/virtual/block/loop4'
kobject: 'loop2' (00000000704d7e59): kobject_uevent_env
RSP: 0018:ffff88818b0bf530 EFLAGS: 00010206
RAX: 0000000000000011 RBX: 0000000000000000 RCX: ffffc9001302b000
kobject: 'loop2' (00000000704d7e59): fill_kobj_path: path
= '/devices/virtual/block/loop2'
RDX: 00000000000000cf RSI: ffffffff81103a68 RDI: 0000000000000088
RBP: ffff88818b0bf8d0 R08: ffff8881bfe8e0c0 R09: 0000000000000008
R10: 0000000000000028 R11: ffffffff810feb0f R12: dffffc0000000000
R13: 0000000000000000 R14: ffffc90007ddfdb8 R15: ffff888188a18400
FS: 00007ff919977700(0000) GS:ffff8881daf00000(0000) knlGS:0000000000000000
kobject: 'loop3' (00000000941a4e7a): kobject_uevent_env
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffffffffff600400 CR3: 00000001cdea0000 CR4: 00000000001426e0
kobject: 'loop3' (00000000941a4e7a): fill_kobj_path: path
= '/devices/virtual/block/loop3'
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
kobject: 'loop5' (000000004f26f0d5): kobject_uevent_env
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
kobject: 'loop5' (000000004f26f0d5): fill_kobj_path: path
= '/devices/virtual/block/loop5'

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