On 03/13/2013 11:35 AM, Eric W. Biederman wrote: > Kees Cook <keescook-F7+t8E8rja9g9hUCZPvPmw@xxxxxxxxxxxxxxxx> writes: > >> Hi, >> >> It seem like we should block (at least) this combination. On 3.9, this >> exploit works once uidmapping is added. >> >> http://www.openwall.com/lists/oss-security/2013/03/13/10 > > Yes. That is a bad combination. It let's chroot confuse privileged > processes. > > Now to figure out if this is easier to squash by adding a user_namespace > to fs_struct or by just forbidding this combination. It's worth making sure that setns(2) doesn't have similar issues. Looking through other shared-but-not-a-namespace things, there are: fs_struct: Buggy as noted. files_struct: Probably harmless -- SCM_RIGHTS can emulate it signal_struct: This interacts with the tty code. Is it okay? sighand_struct: Looks safe. Famous last words. FWIW, I've been alarmed in the past that struct path (e.g. the root directory) implies an mnt_namespace (hidden in struct mount), and it's entirely possible for the root directory's mnt_namespace not to match nsproxy->mnt_namespace. I'm not sure what the implications are, but this doesn't seem healthy. --Andy _______________________________________________ Containers mailing list Containers@xxxxxxxxxxxxxxxxxxxxxxxxxx https://lists.linuxfoundation.org/mailman/listinfo/containers
