Re: [Qemu-stable] [Qemu-devel] [PULL 0/3] Cve 2015 5154 patches

[Peter Lieven]

Am 27.07.2015 um 15:38 schrieb Kevin Wolf:

Am 27.07.2015 um 15:25 hat Stefan Priebe - Profihost AG geschrieben:

Am 27.07.2015 um 14:28 schrieb John Snow:

On 07/27/2015 08:10 AM, Stefan Priebe - Profihost AG wrote:

Am 27.07.2015 um 14:01 schrieb John Snow:

The following changes since commit f793d97e454a56d17e404004867985622ca1a63b:

  Merge remote-tracking branch 'remotes/bonzini/tags/for-upstream' into staging (2015-07-24 13:07:10 +0100)

are available in the git repository at:

  https://github.com/jnsnow/qemu.git tags/cve-2015-5154-pull-request

Any details on this CVE? Is RCE possible? Only if IDE is used?

Stefan

It's a heap overflow. The most likely outcome is a segfault, but the
guest is allowed to continue writing past the end of the PIO buffer at
its leisure. This makes it similar to CVE-2015-3456.

This CVE can be mitigated unlike CVE-2015-3456 by just removing the
CD-ROM drive until the patch can be applied.

Thanks. The seclist article explicitly references xen. So it does not
apply to qemu/kvm? Sorry for asking may be stupid questions.

The IDE emulation is shared between Xen and KVM, so both are affected.
The reason why the seclist mail only mentions Xen is probably because
the Xen security team posted it.

Meanwhile there is also a Red Hat CVE page available, which mentions
qemu-kvm: https://access.redhat.com/security/cve/CVE-2015-5154

The redhat advisory says that some Redhat versions are not affected
"because they did not backport the upstream commit that introduced this issue ".

Can you point out which commit exactly introduced the issue?

Thanks,
Peter