The walk_hugetlb_range() function in 'mm/pagewalk.c' file in the Linux kernel from v4.0-rc1 through v4.15-rc1 mishandles holes in hugetlb ranges, which allows local users to obtain sensitive information from uninitialized kernel memory via crafted use of the mincore() system call.
A flaw was introduced by:
An upstream patch:
Created kernel tracking bugs for this issue:
Affects: fedora-all [bug 1518156]
This issue does not affect the Linux kernel packages as shipped with Red Hat Enterprise Linux 5, 6, 7 and Red Hat Enterprise MRG 2, as a code with the flaw is not present in the products listed.
This issue affects the versions of the Linux kernel as shipped with Red Hat Enterprise Linux 7 for ARM and Red Hat Enterprise Linux 7 for Power LE in the "kernel-alt" packages.
What is Red Hat Enterprise Linux 7 for ARM,
Red Hat Enterprise Linux 7 for Power LE,
and the "kernel-alt" package:
The "kernel-alt" package as shipped with Red Hat Enterprise Linux 7 for ARM and Red Hat Enterprise Linux 7 for Power 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 provided by the "kernel-alt" packages is based on 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 Linux 7
Via RHSA-2018:0502 https://access.redhat.com/errata/RHSA-2018:0502