Race condition in the ecryptfs_mount function in fs/ecryptfs/main.c in the eCryptfs subsystem in the Linux kernel before 3.1 allows local users to bypass intended file permissions via a mount.ecryptfs_private mount with a mismatched uid.
http://lists.opensuse.org/opensuse-security-announce/2011-08/msg00009.html
http://www.kernel.org/pub/linux/kernel/v3.x/ChangeLog-3.1
http://www.ubuntu.com/usn/USN-1188-1
https://bugzilla.redhat.com/show_bug.cgi?id=731172
https://github.com/torvalds/linux/commit/764355487ea220fdc2faf128d577d7f679b91f97