KASAN: user-memory-access Read in sync_vmcs02_to_vmcs12

From: syzbot
Date: Tue Jun 16 2020 - 15:39:16 EST


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=14f70989100000
kernel config: https://syzkaller.appspot.com/x/.config?x=d195fe572fb15312
dashboard link: https://syzkaller.appspot.com/bug?extid=961278f56598a876c889
compiler: gcc (GCC) 9.0.0 20181231 (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+961278f56598a876c889@xxxxxxxxxxxxxxxxxxxxxxxxx

==================================================================
BUG: KASAN: user-memory-access in vmcs12_guest_cr0 arch/x86/kvm/vmx/nested.c:3545 [inline]
BUG: KASAN: user-memory-access in sync_vmcs02_to_vmcs12+0x16fb/0x1a40 arch/x86/kvm/vmx/nested.c:3960
Read of size 18446744071694194346 at addr 0000000001617928 by task systemd-udevd/3877

CPU: 1 PID: 3877 Comm: systemd-udevd 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+0x188/0x20d lib/dump_stack.c:118
__kasan_report mm/kasan/report.c:517 [inline]
kasan_report.cold+0x5/0x37 mm/kasan/report.c:530
vmcs12_guest_cr0 arch/x86/kvm/vmx/nested.c:3545 [inline]
sync_vmcs02_to_vmcs12+0x16fb/0x1a40 arch/x86/kvm/vmx/nested.c:3960
</IRQ>
==================================================================
Kernel panic - not syncing: panic_on_warn set ...
CPU: 1 PID: 3877 Comm: systemd-udevd Tainted: G B 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+0x188/0x20d lib/dump_stack.c:118
panic+0x2e3/0x75c kernel/panic.c:221
end_report+0x4d/0x53 mm/kasan/report.c:104
__kasan_report mm/kasan/report.c:520 [inline]
kasan_report.cold+0xd/0x37 mm/kasan/report.c:530
vmcs12_guest_cr0 arch/x86/kvm/vmx/nested.c:3545 [inline]
sync_vmcs02_to_vmcs12+0x16fb/0x1a40 arch/x86/kvm/vmx/nested.c:3960
</IRQ>
Shutting down cpus with NMI
Kernel Offset: disabled


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