An error handling path in the processing of MMU_MACHPHYS_UPDATE failed
to drop a page reference which was acquired in an earlier processing
Malicious or buggy stub domain kernels or tool stacks otherwise living
outside of Domain0 can mount a denial of service attack which, if
successful, can affect the whole system.
Only domains controlling HVM guests can exploit this vulnerability.
(This includes domains providing hardware emulation services to HVM
Xen versions from at least 3.2.x onwards are vulnerable on x86 systems.
Older versions have not been inspected. ARM systems are not vulnerable.
This vulnerability is only applicable to Xen systems using stub domains
or other forms of disaggregation of control domains for HVM guests.
Red Hat would like to thank the Xen project for reporting this issue.
Created xen tracking bugs for this issue:
Affects: fedora-all [bug 1166914]
Created attachment 960013 [details]
Red Hat Enterprise Linux 5 is now in Production 3 Phase of the support and maintenance life cycle. This has been rated as having Low 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/.