A flaw was found in the way the Linux kernel's KVM subsystem handled non-canonical addresses when emulating instructions that change the RIP (for example, branches or calls). A guest user with access to an I/O or MMIO region could use this flaw to crash the guest.
kvm currently mishandles noncanonical addresses when emulating instructions
that change rip (eg branches, calls), potentially causing a failed VM-entry.
A guest user with access to I/O or MMIO region can use this flaw to crash the
Red Hat would like to thank Nadav Amit for reporting this issue.
This issue does affects the Linux kernel packages as shipped with Red Hat Enterprise Linux 7. Future kernel updates may address this issue.
This issue does affects the Linux kernel packages as shipped with Red Hat Enterprise Linux 6. The risks associated with fixing this bug are greater than its security impact. This issue is not currently planned to be addressed in future kernel updates for Red Hat Enterprise Linux 6.
This issue does affect the kvm packages as shipped with Red Hat Enterprise Linux 5.
Red Hat Enterprise Linux 5 is now in Production 3 Phase of the support and maintenance life cycle. This has been rated as having Moderate security impact and is not currently planned to be addressed in future updates. For additional information, refer to the Red Hat Enterprise Linux Life Cycle: https://access.redhat.com/support/policy/updates/errata/.
This issue has been addressed in the following products:
Red Hat Enterprise Linux 7
Via RHSA-2015:2152 https://rhn.redhat.com/errata/RHSA-2015-2152.html