On Thu, Jun 14, 2007 at 05:18:43PM -0700, david@xxxxxxx wrote: > On Thu, 14 Jun 2007, Jack Stone wrote: > > > david@xxxxxxx wrote: > >> On Sun, 10 Jun 2007, Pavel Machek wrote: > >>> But you have that regex in _user_ space, in a place where policy > >>> is loaded into kernel. > >> > >> then the kernel is going to have to call out to userspace every time a > >> file is created or renamed and the policy is going to be enforced > >> incorrectly until userspace finished labeling/relabeling whatever is > >> moved. building this sort of race condigion for security into the kernel > >> is highly questionable at best. > >> > >>> AA has regex parser in _kernel_ space, which is very wrong. > >> > >> see Linus' rants about why it's not automaticaly the best thing to move > >> functionality into userspace. > >> > >> remember that the files covered by an AA policy can change as files are > >> renamed. this isn't the case with SELinux so it doesn't have this sort > >> of problem. > > > > How about using the inotify interface on / to watch for file changes and > > updating the SELinux policies on the fly. This could be done from a > > userspace daemon and should require minimal SELinux changes. > > > > The only possible problems I can see are the (hopefully) small gap > > between the file change and updating the policy and the performance > > problems of watching the whole system for changes. > > as was mentioned by someone else, if you rename a directory this can result > in millions of files that need to be relabeled (or otherwise have the policy > changed for them) > > that can take a significant amount of time to do. So? The number of "real-world" times that this happens is probably non-existant on a "production" server. And if you are doing this on a developer machine, then yes, there might be some slow-down, but no more than is currently happening with tools like Beagle that people are already shipping and supporting in "enterprise" solutions. thanks, greg k-h - 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
