A flaw was found in the Linux kernels implementation of valid_master_desc() in which a memory buffer would be compared to a userspace value with an incorrect size of comparison. By bruteforcing the comparison an attacker could determine what was in memory after the description.
This could allow a local attacker to obtain possibly sensitive information from kernel memory.
This issue has been addressed in the following products:
Red Hat Enterprise MRG 2
Via RHSA-2018:2165 https://access.redhat.com/errata/RHSA-2018:2165