Re: [kernel-hardening] Re: [PATCH resend 2/2] userns: control capabilities of some user namespaces

["Serge E. Hallyn" <serge@hallyn.com>]

Quoting Mahesh Bandewar (महेश बंडेवार) (maheshb@google.com):
> Of course. Let's take an example of the CVE that I have mentioned in
> my cover-letter -
> CVE-2017-7308(https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2017-7308).
> It's well documented and even has a
> exploit(https://github.com/xairy/kernel-exploits/tree/master/CVE-2017-7308)
> c-program that can demonstrate how it can be used against non-patched
> kernel. There is very nice blog
> post(https://googleprojectzero.blogspot.kr/2017/05/exploiting-linux-kernel-via-packet.html)
> about this vulnerability by Andrey Konovalov.

Ok, thanks.  It's a good example because the fix for this CVE actually
came by itself (http://kernel.ubuntu.com/git/ubuntu/ubuntu-xenial.git/tree/debian.master/changelog).
Normally multiple CVEs come at the same time, which would make a
workaround for one now helpful.  This is a good counter-example.

I'm going to maintain that I really don't like this.  But it looks
useful, so ack on the concept, I'll just have to look again at the
code now.  Thanks for indulging me.

-serge