Updated glibc packages fix security vulnerabilities

The vfprintf function in stdio-common/vfprintf.c in GNU C Library (aka glibc) 2.5, 2.12, and probably other versions does not “properly restrict the use of” the alloca function when allocating the SPECS array, which allows context- dependent attackers to bypass the FORTIFY_SOURCE format-string protection mechanism and cause a denial of service (crash) or possibly execute arbitrary code via a crafted format string using positional parameters and a large number of format specifiers (CVE-2012-3406). The nss_dns implementation of getnetbyname could run into an infinite loop if the DNS response contained a PTR record of an unexpected format (CVE-2014-9402). Also glibc lock elision (new feature in glibc 2.18) has been disabled as it can break glibc at runtime on newer Intel hardware (due to hardware bug)