The __get_user_asm_ex macro in arch/x86/include/asm/uaccess.h in the Linux
kernel 4.4.22 through 4.4.28 contains extended asm statements that are
incompatible with the exception table, which allows local users to obtain root
access on non-SMEP platforms via a crafted application. NOTE: this
vulnerability exists because of incorrect backporting of the CVE-2016-9178 patch
to older kernels.
Above refers to a new issue which affected some Linux stable lines, which backported 1c109fabbd51863475cd12ac206bdd249aee35af without also backporting 548acf19234dbda5a52d5a8e7e205af46e9da840.
Created kernel tracking bugs for this issue:
Affects: fedora-all [bug 1415125]