arch/ia64/xen/faults.c in Xen 3.4 and 4.0 in Linux kernel 2.6.18, and possibly other kernel versions, when running on IA-64 architectures, allows local users to cause a denial of service and "turn on BE by modifying the user mask of the PSR," as demonstrated via exploitation of CVE-2006-0742.
tools/libxc/xcdombzimageloader.c in Xen 3.2, 3.3, 4.0, and 4.1 allows local users to cause a denial of service (management software infinite loop and management domain resource consumption) via unspecified vectors related to "Lack of error checking in the decompression loop."
Multiple integer overflows in tools/libxc/xcdombzimageloader.c in Xen 3.2, 3.3, 4.0, and 4.1 allow local users to cause a denial of service and possibly execute arbitrary code via a crafted paravirtualised guest kernel image that triggers (1) a buffer overflow during a decompression loop or (2) an out-of-bounds read in the loader involving unspecified length fields.