On 06/08/2015 03:27 PM, Steve Beattie wrote: > On Fri, Jun 05, 2015 at 03:24:23PM -0700, John Johansen wrote: >> Currently the cache file has its mtime set to its creation time, but this >> can lead to cache issues when a policy file is updated separately from >> the cache file so that is possible a policy file is newer than the >> what the cache file was generated from but still fails the comparison >> because the generated cache file has a newer timestamp. >> >> Signed-off-by: John Johansen <[email protected]> > > So I think this is still problematic in Ubuntu given how the > /etc/apparmor.d/local/ includes are implemented; they are generated yes timestamps are still problematic
> by dh_apparmor at package postinst time iff the local/ include file > doesn't already exist. This means the generated include gets an mtime > of the package install, and therefore so will the cache file. > yes > Consider the sequence of events for package foo: > > (1) foo version n+1 is built with a policy update for foo > (2) foo version n is installed > + /etc/apparmor.d/local/foo gets an mtime of (2) > + therefore /etc/apparmor.d/local/foo also gets an mtime of (2) > (3) foo is upgraded to version n+1 > + mtime of foo's cache file (2) is still newer than the policy > mtime for foo (1), so the cache blob is used (incorrectly). > + even if we required the mtime to be exactly the same, the cache > blob would still be (incorrectly) used (unless we recorded > the mtime for all files), because the local/foo file is the > most recently updated policy element for foo. > yep this will fail with this > But it's possible I might be confused. > The case it closes is 1) n+1 is built 2) n is installed, and doesn't generate new files 3) upgrade to n+1 in this case the cache with have n's timestamp, the only way to fix the case you bring up is hashing -- AppArmor mailing list [email protected] Modify settings or unsubscribe at: https://lists.ubuntu.com/mailman/listinfo/apparmor
