arch/x86/kernel/entry_64.S in the Linux kernel before 3.17.5 does not properly handle faults associated with the Stack Segment (SS) segment register, which allows local users to gain privileges by triggering an IRET instruction that leads to access to a GS Base address from the wrong space.
git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git%3Ba=commit%3Bh=6f442be2fb22be02cafa606f1769fa1e6f894441
lists.opensuse.org/opensuse-security-announce/2015-03/msg00025.html
lists.opensuse.org/opensuse-security-announce/2015-04/msg00015.html
lists.opensuse.org/opensuse-security-announce/2015-04/msg00020.html
marc.info/?l=bugtraq&m=142722450701342&w=2
marc.info/?l=bugtraq&m=142722544401658&w=2
osvdb.org/show/osvdb/115919
rhn.redhat.com/errata/RHSA-2014-1998.html
rhn.redhat.com/errata/RHSA-2014-2008.html
rhn.redhat.com/errata/RHSA-2014-2028.html
rhn.redhat.com/errata/RHSA-2014-2031.html
rhn.redhat.com/errata/RHSA-2015-0009.html
secunia.com/advisories/62336
source.android.com/security/bulletin/2016-04-02.html
www.exploit-db.com/exploits/36266
www.openwall.com/lists/oss-security/2014/12/15/6
www.ubuntu.com/usn/USN-2491-1
www.zerodayinitiative.com/advisories/ZDI-16-170
bugzilla.redhat.com/show_bug.cgi?id=1172806
github.com/torvalds/linux/commit/6f442be2fb22be02cafa606f1769fa1e6f894441
help.joyent.com/entries/98788667-Security-Advisory-ZDI-CAN-3263-ZDI-CAN-3284-and-ZDI-CAN-3364-Vulnerabilities
www.kernel.org/pub/linux/kernel/v3.x/ChangeLog-3.17.5