CVE-2011-2203 kernel: hfs_find_init() sb->ext_tree NULL pointer dereference
http://www.securityfocus.com/bid/48236
https://lkml.org/lkml/2011/6/8/154
https://bugzilla.redhat.com/show_bug.cgi?id=712774
http://www.openwall.com/lists/oss-security/2011/06/13/16
http://www.ubuntu.com/usn/USN-1328-1
http://www.ubuntu.com/usn/USN-1324-1
http://www.ubuntu.com/usn/USN-1344-1
http://secunia.com/advisories/47754