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From: syzbot <syzbot+e0240f9c36530bda7130@syzkaller.appspotmail.com>
To: bp@alien8.de, hpa@zytor.com, jmattson@google.com,
	joro@8bytes.org, kvm@vger.kernel.org,
	linux-kernel@vger.kernel.org, mingo@redhat.com,
	pbonzini@redhat.com, sean.j.christopherson@intel.com,
	syzkaller-bugs@googlegroups.com, tglx@linutronix.de,
	vkuznets@redhat.com, wanpengli@tencent.com, x86@kernel.org
Subject: KASAN: out-of-bounds Read in kvm_arch_hardware_setup
Date: Sat, 27 Jun 2020 13:01:13 -0700	[thread overview]
Message-ID: <000000000000a0784a05a916495e@google.com> (raw)

Hello,

syzbot found the following crash on:

HEAD commit:    7ae77150 Merge tag 'powerpc-5.8-1' of git://git.kernel.org..
git tree:       upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=1654e385100000
kernel config:  https://syzkaller.appspot.com/x/.config?x=be4578b3f1083656
dashboard link: https://syzkaller.appspot.com/bug?extid=e0240f9c36530bda7130
compiler:       clang version 10.0.0 (https://github.com/llvm/llvm-project/ c2443155a0fb245c8f17f2c1c72b6ea391e86e81)
syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=15f3abc9100000
C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=131b7bb5100000

IMPORTANT: if you fix the bug, please add the following tag to the commit:
Reported-by: syzbot+e0240f9c36530bda7130@syzkaller.appspotmail.com

==================================================================
BUG: KASAN: out-of-bounds in kvm_cpu_cap_get arch/x86/kvm/cpuid.h:292 [inline]
BUG: KASAN: out-of-bounds in kvm_cpu_cap_has arch/x86/kvm/cpuid.h:297 [inline]
BUG: KASAN: out-of-bounds in kvm_init_msr_list arch/x86/kvm/x86.c:5362 [inline]
BUG: KASAN: out-of-bounds in kvm_arch_hardware_setup+0xb05/0xf40 arch/x86/kvm/x86.c:9802
Read of size 4 at addr ffffffff896c3134 by task syz-executor614/6786

CPU: 1 PID: 6786 Comm: syz-executor614 Not tainted 5.7.0-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 <IRQ>
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x1e9/0x30e lib/dump_stack.c:118
 print_address_description+0x66/0x5a0 mm/kasan/report.c:383
 __kasan_report mm/kasan/report.c:513 [inline]
 kasan_report+0x132/0x1d0 mm/kasan/report.c:530
 kvm_cpu_cap_get arch/x86/kvm/cpuid.h:292 [inline]
 kvm_cpu_cap_has arch/x86/kvm/cpuid.h:297 [inline]
 kvm_init_msr_list arch/x86/kvm/x86.c:5362 [inline]
 kvm_arch_hardware_setup+0xb05/0xf40 arch/x86/kvm/x86.c:9802
 </IRQ>

The buggy address belongs to the variable:
 kvm_cpu_caps+0x24/0x50

Memory state around the buggy address:
 ffffffff896c3000: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffffffff896c3080: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffffffff896c3100: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
                                        ^
 ffffffff896c3180: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffffffff896c3200: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
==================================================================


---
This bug is generated by a bot. It may contain errors.
See https://goo.gl/tpsmEJ for more information about syzbot.
syzbot engineers can be reached at syzkaller@googlegroups.com.

syzbot will keep track of this bug report. See:
https://goo.gl/tpsmEJ#status for how to communicate with syzbot.
syzbot can test patches for this bug, for details see:
https://goo.gl/tpsmEJ#testing-patches

             reply	other threads:[~2020-06-27 20:01 UTC|newest]

Thread overview: 5+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-06-27 20:01 syzbot [this message]
2020-06-29 15:25 ` KASAN: out-of-bounds Read in kvm_arch_hardware_setup Paolo Bonzini
2020-06-29 15:29   ` Andrey Konovalov
2020-06-29 15:35     ` Sean Christopherson
2020-06-30  6:12 ` Sean Christopherson

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