In the Linux kernel through 4.14.13, the rds_message_alloc_sgs() function does not validate a value that is used during DMA page allocation, leading to a heap-based out-of-bounds write (related to the rds_rdma_extra_size() function in 'net/rds/rdma.c') and thus to a system panic. Due to the nature of the flaw, privilege escalation cannot be fully ruled out, although we believe it is unlikely.
An upstream patch:
Created kernel tracking bugs for this issue:
Affects: fedora-all [bug 1533895]
This issue affects the versions of the Linux kernel as shipped with Red Hat Enterprise Linux 6 and Red Hat Enterprise MRG 2. Future Linux kernel updates for the respective releases may address this issue.
This issue does not affect the versions of the Linux kernel as shipped with Red Hat Enterprise Linux 5, 7, its real-time kernel, Red Hat Enterprise Linux 7 for ARM 64 and Red Hat Enterprise Linux 7 for Power 9 LE, as a code with the flaw is not built and shipped with the products listed.
What is Red Hat Enterprise Linux 7 for ARM 64,
Red Hat Enterprise Linux 7 for Power 9 LE
The kernel package as shipped with Red Hat Enterprise Linux 7 for ARM 64 and Red Hat Enterprise Linux 7 for Power 9 LE is an updated kernel intended to support new architectures not available at the time of Red Hat Enterprise Linux 7 original shipping. The new kernel version is based on an upstream Linux kernel version 4.11. The offering is distributed with other updated packages, but most of the userspace is the standard Red Hat Enterprise Linux 7 Server RPM files.
For more information please refer to:
This issue has been addressed in the following products:
Red Hat Enterprise MRG 2
Via RHSA-2018:0470 https://access.redhat.com/errata/RHSA-2018:0470