A flaw was found in the Linux kernel which allowed an attacker who is able to add or remove serial devices to exploit a race condition in the serial port handling. This would cause the system to panic or possibly have unspecified other impact because the port->exists value can change after it is validated.
This issue affects the Linux kernel packages as shipped with Red Hat Enterprise Linux 5, 6, 7, its real-time kernel and Red Hat Enterprise MRG 2. At this time there are no plans to fix this issue.
This issue does not affect the versions of the Linux kernel as shipped with Red Hat Enterprise Linux 7 for ARM 64 and Red Hat Enterprise Linux 7 for Power 9 LE.