On Thu, Feb 11, 2010 at 12:21:00PM -0500, Christoph Hellwig wrote: > On Wed, Feb 10, 2010 at 12:15:53PM +0100, Miklos Szeredi wrote: > > - renamed flag to UMOUNT_NOFOLLOW > > - added UMOUNT_UNUSED for feature detection > > Umm, why? MNT_ certainly isn't the best naming for unmount flags, > but switching convention after we had a few doesn't make any sense. Actually, I've got more interesting question: what's being attempted there? Is that just a "let's protect ourselves against somebody feeding us an untrusted symlink"? I'm not sure if it makes much sense; if we are dealing with pathnames on untrusted fs, there's nothing to stop the attacker from having /mnt/foo/dir (originally containing a mountpoint at /mnt/foo/dir/usr) killed and replaced with a symlink to /, making any code that does umount() on such pathnames vulnerable as hell anyway. Lack of LOOKUP_FOLLOW affects only the last pathname component. So what is that patch trying to make safe? -- 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
