Re: CVE request: perf: may parse user-controlled config file

[Steve Grubb <sgrubb () redhat com>]

On Tuesday, August 09, 2011 09:25:24 AM Yves-Alexis Perez wrote:
> On mar., 2011-08-09 at 09:18 -0400, Steve Grubb wrote:
> > And in recent kernels has an executable stack:
> > https://bugzilla.redhat.com/show_bug.cgi?id=704296
>
> We don't have access to that bug.

Its marked as a security bug and I guess its not been reclassified. The short of it is 
this:

/usr/bin/eu-readelf -l /usr/bin/perf  | grep STACK

If you get RWE for the permissions, its executable. If you get RW, then everything is 
fine. While this itself is not exploitable, if there were any other problems then this 
could be susceptible to putting shell code on the stack which should have been 
banished long ago. IOW, the ease of exploit goes up since you don't need to defeat any 
advanced security mechanisms like ASLR.

I have a number of security assessment utilities located here:
http://people.redhat.com/sgrubb/security/
that can scan systems looking for problems like this. Some are rpm centric because 
once you find a problem you want to know the associated package, but they could be 
easily modified for other packaging tools.

-Steve