On Tue, Nov 09, 2010 at 01:05:06PM -0500, Dave Jones wrote: > On the subject of randomisation, this article.. > http://labs.mwrinfosecurity.com/notices/assessing_the_tux_strength_part_2_into_the_kernel/ > bugged me. Notably the discrepancy between Fedora and everyone else on the > shlib test. > I didn't get around to testing whether this was a side-effect of the > ascii-armor patch. > > I also couldn't reproduce the results the article author noted, on 32bit or > 64bit, > but iirc, it was still lower than the results for everyone else. > > any ideas for what could be the cause ?
When I read that, I assumed so, yes. Their methodology[1] wasn't great. The only way that I can see them getting those results were from running Fedora on 32bit and Ubuntu on 64bit, but that seems unlikely given the measured bit size on the other tests. I would have expected Fedora and Ubuntu to behave the same entropy-wise (poorly) for 32bit non-NX. Unfortunately, they didn't really specify what hardware or images they used. (Ubuntu's 32 and 64 bit kernels have the same suffix "-generic".) I suspect another factor may be that paxtest can give inconsistent output when doing the ASLR test. -Kees [1] http://www.outflux.net/blog/archives/2010/09/07/cross-distro-default-security-protection-review/ -- Kees Cook Ubuntu Security Team _______________________________________________ kernel mailing list kernel@lists.fedoraproject.org https://admin.fedoraproject.org/mailman/listinfo/kernel
