Several vulnerabilities have been discovered in the Linux kernel that may lead to a denial of service or privilege escalation. The Common Vulnerabilities and Exposures project identifies the following problems: CVE-2013-0231 Jan Beulich provided a fix for an issue in the Xen PCI backend drivers. Users of guests on a system using passed-through PCI devices can create a denial of service of the host system due to the use of non-ratelimited kernel log messages. CVE-2013-0871 Suleiman Souhlal and Salman Qazi of Google, with help from Aaron Durbin and Michael Davidson of Google, discovered an issue in the ptrace subsystem. Due to a race condition with PTRACE_SETREGS, local users can cause kernel stack corruption and execution of arbitrary code.