Messages in this thread | | | Date | Thu, 14 Jun 2007 17:18:43 -0700 (PDT) | From | david@lang ... | Subject | Re: [AppArmor 39/45] AppArmor: Profile loading and manipulation, pathname matching |
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On Thu, 14 Jun 2007, Jack Stone wrote:
> david@lang.hm 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.
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