Re: CVE request Qemu: i386: null pointer dereference in vapic_write

[cve-assign () mitre org]

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> Qemu emulator built with the TPR optimization for 32-bit Windows guests 
> support is vulnerable to a null pointer dereference flaw. It occurs while 
> doing I/O port write operations via hmp interface. In that, 'current_cpu' 
> remains null, which leads to the null pointer dereference.
>
> A user/process could use this flaw to crash the Qemu instance, resulting in 
> DoS issue.
>
> https://lists.gnu.org/archive/html/qemu-devel/2016-01/msg02812.html
> https://bugzilla.redhat.com/show_bug.cgi?id=1283934

> > When I/O port write operation is called from hmp interface,
> > 'current_cpu' remains null, as it is not called from cpu_exec()
> > loop. This leads to a null pointer dereference in vapic_write
> > routine. Add check to avoid it.

Use CVE-2016-1922.     

This is not yet available at
http://git.qemu.org/?p=qemu.git;a=history;f=hw/i386/kvmvapic.c but
that may be an expected place for a later update.

- -- 
CVE assignment team, MITRE CVE Numbering Authority
M/S M300
202 Burlington Road, Bedford, MA 01730 USA
[ PGP key available through http://cve.mitre.org/cve/request_id.html ]
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