The sock_alloc_send_pskb function in net/core/sock.c in the Linux kernel before 3.4.5 does not properly validate a certain length value, which allows local users to cause a denial of service (heap-based buffer overflow and system crash) or possibly gain privileges by leveraging access to a TUN/TAP device.
git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git%3Ba=commit%3Bh=cc9b17ad29ecaa20bfe426a8d4dbfb94b13ff1cc
rhn.redhat.com/errata/RHSA-2012-0743.html
rhn.redhat.com/errata/RHSA-2012-1087.html
secunia.com/advisories/50807
ubuntu.com/usn/usn-1529-1
www.kernel.org/pub/linux/kernel/v3.x/ChangeLog-3.4.5
www.securityfocus.com/bid/53721
www.ubuntu.com/usn/USN-1535-1
bugzilla.redhat.com/show_bug.cgi?id=816289
github.com/torvalds/linux/commit/cc9b17ad29ecaa20bfe426a8d4dbfb94b13ff1cc