Race condition in the install_user_keyrings function in security/keys/process_keys.c in the Linux kernel before 3.8.3 allows local users to cause a denial of service (NULL pointer dereference and system crash) via crafted keyctl system calls that trigger keyring operations in simultaneous threads.
git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git%3Ba=commit%3Bh=0da9dfdd2cd9889201bc6f6f43580c99165cd087
lists.opensuse.org/opensuse-security-announce/2013-07/msg00018.html
lists.opensuse.org/opensuse-security-announce/2014-02/msg00002.html
rhn.redhat.com/errata/RHSA-2013-0744.html
www.kernel.org/pub/linux/kernel/v3.x/ChangeLog-3.8.3
www.mandriva.com/security/advisories?name=MDVSA-2013:176
www.openwall.com/lists/oss-security/2013/03/07/1
www.ubuntu.com/usn/USN-1787-1
www.ubuntu.com/usn/USN-1788-1
www.ubuntu.com/usn/USN-1792-1
www.ubuntu.com/usn/USN-1793-1
www.ubuntu.com/usn/USN-1794-1
www.ubuntu.com/usn/USN-1795-1
www.ubuntu.com/usn/USN-1796-1
www.ubuntu.com/usn/USN-1797-1
www.ubuntu.com/usn/USN-1798-1
bugzilla.redhat.com/show_bug.cgi?id=916646
github.com/torvalds/linux/commit/0da9dfdd2cd9889201bc6f6f43580c99165cd087