The SelectionOwner::ProcessTarget function in ui/base/x/selection_owner.cc in the UI implementation in Google Chrome before 40.0.2214.91 uses an incorrect data type for a certain length value, which allows remote attackers to cause a denial of service (out-of-bounds read) via crafted X11 data.
https://codereview.chromium.org/697863002
https://code.google.com/p/chromium/issues/detail?id=428557
http://www.securitytracker.com/id/1031623
http://www.securityfocus.com/bid/72288
http://security.gentoo.org/glsa/glsa-201502-13.xml
http://secunia.com/advisories/62665
http://secunia.com/advisories/62383
http://rhn.redhat.com/errata/RHSA-2015-0093.html
http://lists.opensuse.org/opensuse-security-announce/2015-03/msg00005.html
http://googlechromereleases.blogspot.com/2015/01/stable-update.html