Ubuntu Security Notice USN-137-1 – Alexander Nyberg discovered that ptrace() insufficiently validated addresses on the amd64 platform so that it was possible to set an invalid segment base. A local attacker could exploit this to crash the kernel. This does not affect the i386 and powerpc platforms in any way. Chris Wright discovered that the mmap() function could create illegal memory maps (using the “mmap” function) with the start address pointing beyond the end address. A local user could exploit this to crash the kernel or possibly even execute arbitrary code with kernel privileges.
You can download this advisory from the following link: https://packetstormsecurity.com/files/download/38133/USN-137-1.txt
Source: https://packetstormsecurity.com/files/38133/Ubuntu-Security-Notice-137-1.html