On Wed, Apr 16, 2014 at 11:13:31AM -0700, Andy Lutomirski wrote: > On Wed, Apr 16, 2014 at 11:06 AM, Vivek Goyal <vgo...@redhat.com> wrote: > > On Wed, Apr 16, 2014 at 09:31:25AM -0700, Andy Lutomirski wrote: > > I am not sure how same issue with happen with cgroups. In the case of > > socket example, you are forcing a setuid program to write to standard > > output and that setuid program will run in same cgroup as caller and > > will have same cgroup as caller. So even if somebody was using cgroup > > information for authentication, atleast in this particular case it > > will not be a problem. Both unpriviliged and priviliged programs has > > same cgroups. > > > > I'm not sure that there's an actual attackable program. But I also > see no reason to be convinced that there isn't one, and the problem > can easily be avoided by requiring programs to explicitly ask to send > their cgroup.
If you can't prove that there is something fundamentally wrong with passing cgroup info to receiver, there is no reason to block these patches either. We can't fix the problems which we can't see. You are saying that I don't know what kind of problem can happen due to cgroup passing. Still that does not mean none of the problems exist. So let us not pass cgroup info by default and ask client to opt in. I don't think this is a very convincing argument. To me, if we can't see anything fundamentally wrong with passing cgroup info, we should take these patches in. And once we figure out that there is are problematic use cases, then implement SO_NOPASSCGROUP and SO_NOPEERCRED and allow problematic clients to opt out. Thanks Vivek -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
