syzbot


KASAN: out-of-bounds Read in kvm_arch_hardware_setup

Status: closed as dup on 2020/06/30 06:12
Subsystems: kvm
[Documentation on labels]
Reported-by: syzbot+e0240f9c36530bda7130@syzkaller.appspotmail.com
First crash: 1395d, last: 1395d
Duplicate of
Title Repro Cause bisect Fix bisect Count Last Reported
general protection fault in syscall_return_slowpath kernel syz inconclusive done 1 1416d 1503d
Discussions (1)
Title Replies (including bot) Last reply
KASAN: out-of-bounds Read in kvm_arch_hardware_setup 4 (5) 2020/06/30 06:12

Sample crash report:
==================================================================
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
==================================================================

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2020/06/23 19:56 upstream 7ae77150d94d 54566aff .config console log report syz C ci-upstream-kasan-gce-smack-root
* Struck through repros no longer work on HEAD.