A flaw was discovered in the kernel's collect_mounts function. If the kernel's audit subsystem called collect_mounts to audit an unmounted path, it could panic the system. With this flaw, an unprivileged user could call umount(MNT_DETACH) to launch a denial-of-service attack.
The audit subsystem can call collect_mounts, which if attempting to audit
a mountpoint which is no longer mounted can panic the system.
This issue does not affect the Linux kernels as shipped with Red Hat Enterprise Linux 5, 6, MRG-2, realtime and arm-kernels.
The issue is not currently planned to be addressed in Red Hat Enterprise Linux 7.