This bug has been copied from bug #700565 and has been proposed to be backported to 5.7 z-stream (EUS).
in kernel-2.6.18-274.1.1.el5 xen-fix-x86_emulate-handling-of-imul-with-immediate-operands.patch
Technical note added. If any revisions are required, please edit the "Technical Notes" field accordingly. All revisions will be proofread by the Engineering Content Services team. New Contents: A bug was found in the way the x86_emulate() function handled the IMUL instruction in the Xen hypervisor. On systems without support for hardware assisted paging (HAP), such as those running CPUs that do not have support for (or those that have it disabled) Intel Extended Page Tables (EPT) or AMD Virtualization (AMD-V) Rapid Virtualization Indexing (RVI), this bug could cause fully-virtualized guests to crash or lead to silent memory corruption. In reported cases, this issue occurred when booting fully-virtualized Red Hat Enterprise Linux 6.1 guests with memory cgroups enabled on a Red Hat Enterprise Linux 5.7 host.
Technical note updated. If any revisions are required, please edit the "Technical Notes" field accordingly. All revisions will be proofread by the Engineering Content Services team. Diffed Contents: @@ -1 +1,2 @@ -A bug was found in the way the x86_emulate() function handled the IMUL instruction in the Xen hypervisor. On systems without support for hardware assisted paging (HAP), such as those running CPUs that do not have support for (or those that have it disabled) Intel Extended Page Tables (EPT) or AMD Virtualization (AMD-V) Rapid Virtualization Indexing (RVI), this bug could cause fully-virtualized guests to crash or lead to silent memory corruption. In reported cases, this issue occurred when booting fully-virtualized Red Hat Enterprise Linux 6.1 guests with memory cgroups enabled on a Red Hat Enterprise Linux 5.7 host.+A bug was found in the way the x86_emulate() function handled the IMUL instruction in the Xen hypervisor. On systems that have no support for hardware assisted paging (such as those running CPUs that do not have support +for Intel Extended Page Tables or AMD Rapid Virtualization Indexing), or have it disabled, this bug could cause fully-virtualized guests to crash or lead to silent memory corruption. In reported cases, this issue occurred when booting fully-virtualized Red Hat Enterprise Linux 6.1 guests with memory cgroups enabled.
An advisory has been issued which should help the problem described in this bug report. This report is therefore being closed with a resolution of ERRATA. For more information on therefore solution and/or where to find the updated files, please follow the link below. You may reopen this bug report if the solution does not work for you. http://rhn.redhat.com/errata/RHSA-2011-1212.html