Re: Xen Security Advisory 90 - Linux netback crash trying to disable due to malformed packet

[Ian Campbell <Ian.Campbell () citrix com>]

On Mon, 2014-03-24 at 15:47 -0400, cve-assign () mitre org wrote:
> > XSA-90
>
> > it tries to disable the interface ... This involves taking a mutex ...
> > sleeping is not allowed ... The end result is that the backend domain
> > (often, Dom0) crashes with "scheduling while atomic". Malicious guest
> > administrators can cause denial of service.
>
> Use CVE-2014-2580.

Thanks.

> > This bug was publicly reported on xen-devel, before it was appreciated
> > that there was a security problem. The public mailing list thread
> > nevertheless contains information strongly suggestive of a security
> > bug, and a different security bug (with CVE) is suggested as seeming
> > "similar".
>
> We didn't happen to notice a CVE ID of a similar bug within xen-devel.

The first mail in the thread (<5324B182.70905 () etorok net>) had a link to
https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=701744#88 which was a
bug relating to CVE-2013-0216.

> In some cases, we would use that bug's CVE ID (if available) within a
> "NOTE:" sentence at the end of a new vulnerability's CVE description.
>
> http://lists.xen.org/archives/html/xen-devel/2014-03/msg02707.html
> says "by removing these checks we are introducing a way for a
> malicious or buggy guest to trigger misbehaviour in the backend,
> leading to e.g. a DoS" but we haven't tried to track down whether that
> is directly applicable.

This was review of a separate patch unrelated to the bug in question.

HTH,

Ian.