On Tue, Jul 23, 2013 at 11:50 PM, Eric W. Biederman <ebiederm@xxxxxxxxxxxx> wrote: > Andy Lutomirski <luto@xxxxxxxxxxxxxx> writes: >> On Tue, Jul 23, 2013 at 11:30 AM, Eric W. Biederman >> <ebiederm@xxxxxxxxxxxx> wrote: >>> >>> When creating a less privileged mount namespace or propogating mounts >>> from a more privileged to a less privileged mount namespace lock the >>> submounts so they may not be unmounted individually in the child mount >>> namespace revealing what is under them. >> >> I would propose a different rule: if vfsmount b is mounted on vfsmount >> a, then to unmount b, you must be ns_capable(CAP_SYS_MOUNT) on either >> a's namespace or b's namespace. The idea is that you should be able >> to see under a mount if you own the parent (because it's yours) or if >> you own the child (because you, or someone no more privileged than >> you, put it there). This may result in a simpler patch and should do >> much the same thing. > > It definitely won't result in a simpler patch as the information you are > basing the decision on is not available. > Ah, I see -- mnt_ns gets changed when the namespace is duplicated. Acked-by: Andy Lutomirski <luto@xxxxxxxxxxxxxx> --Andy -- To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
