The tcp_illinois_info function in net/ipv4/tcp_illinois.c in the Linux kernel before 3.4.19, when the net.ipv4.tcp_congestion_control illinois setting is enabled, allows local users to cause a denial of service (divide-by-zero error and OOPS) by reading TCP stats.
https://bugzilla.redhat.com/show_bug.cgi?id=871848
http://www.ubuntu.com/usn/USN-1652-1
http://www.ubuntu.com/usn/USN-1651-1
http://www.ubuntu.com/usn/USN-1650-1
http://www.ubuntu.com/usn/USN-1649-1
http://www.ubuntu.com/usn/USN-1648-1
http://www.ubuntu.com/usn/USN-1647-1
http://www.ubuntu.com/usn/USN-1646-1
http://www.ubuntu.com/usn/USN-1645-1
http://www.ubuntu.com/usn/USN-1644-1
http://www.securityfocus.com/bid/56346
http://www.openwall.com/lists/oss-security/2012/10/31/5
http://www.kernel.org/pub/linux/kernel/v3.x/ChangeLog-3.4.19
http://secunia.com/advisories/51409
http://rhn.redhat.com/errata/RHSA-2012-1580.html
http://lists.fedoraproject.org/pipermail/package-announce/2012-November/091110.html