The do_tmem_op function in the Transcendent Memory (TMEM) in Xen 4.0 4.1 and 4.2 allow local guest OS users to cause a denial of service (host crash) and possibly have other unspecified impacts via unspecified vectors related to \broken locking checks\ in an \error path.\ NOTE: this issue was originally published as part of CVE-2012-3497 which was too general; CVE-2012-3497 has been SPLIT into this ID and others.