Re: qemu-system-x86_64: mov_ss_trap_64 PANIC: double fault, error_code: 0x0

[Dan Rue]

On Mon, Jun 25, 2018 at 08:47:40AM -0700, Andy Lutomirski wrote:
> On Sun, Jun 24, 2018 at 10:41 PM Naresh Kamboju
> <naresh.kamboju@xxxxxxxxxx> wrote:
> >
> > Kselftest test case mov_ss_trap_64 is causing kernel panic on
> > qemu-system-x86_64 and PASS on real x86_64 hardware.
> >
> > Test code snippet,
> > main() {
> > <>
> >       printf("[RUN]\tMOV SS; CS CS INT3\n");
> >       asm volatile ("mov %[ss], %%ss; .byte 0x2e, 0x2e; int3" :: [ss] "m" (ss));
> > <>
> > }
> >
> 
> This smells like CVE-2018-1087.  Can you confirm that your *host*
> kernel is patched?
> 
> CVE-2018-1087 is extremely severe, and if your host kernel is not
> patched, I think you need to apply some serious pressure on your
> vendor to get with the program.

Thanks Andy - that was exactly it. We updated our host running debian
stretch to the latest kernel (per
https://security-tracker.debian.org/tracker/CVE-2018-1087), and the
symptom was no longer seen. Thanks for the pointer.

Dan

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Linux Kernel Functional Testing (LKFT)
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