On Tue, Apr 15, 2014 at 08:47:54PM -0700, Andy Lutomirski wrote: [..] > Here's an attack against SO_PASSCGROUP, as you implemented it: connect > a socket and get someone else to write(2) to it. This isn't very > hard. Now you've impersonated. If this is a problem then I think kernel requires fixing. Because kernel will apply all resource management policies based on the cgroup at write(2) time and not based on open() time. For example, blkio throttling policies. If you get a process in other cgroup to read/write to an fd, then IO throttling rules of that cgroup are applied and it does not matter who opened fd in first place. So SO_PASSCGROUP is not exactly same as SO_PASSCRED in that sense. If there are issues w.r.t authorization/authentication etc, then that should be a recommendation to user space that don't use cgroup info for unsafe cases. Thanks Vivek -- To unsubscribe from this list: send the line "unsubscribe cgroups" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
