The init_new_context function in arch/x86/include/asm/mmu_context.h in the Linux kernel before 4.12.10 does not correctly handle errors from LDT table allocation when forking a new process, allowing a local attacker to achieve a use-after-free or possibly have unspecified other impact by running a specially crafted program.
An upstream patch:
Created kernel tracking bugs for this issue:
Affects: fedora-all [bug 1518642]
Fedora hasn't supported a 4.12.x kernel in quite some time. Current kernels are 4.13.16 across all supported releases.
This issue does not affect the Linux kernel packages as shipped with Red Hat Enterprise Linux 5, 6 and 7, its real-time kernel, Red Hat Enterprise MRG 2, 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 present or is not built in the products listed.
This issue has been addressed in the following products:
Red Hat Enterprise Linux 7
Via RHSA-2018:0676 https://access.redhat.com/errata/RHSA-2018:0676