Event channels control structures can be accessed lockless as long as the port is considered to be valid. Such sequence is missing appropriate memory barrier (e.g smp_*mb()) to prevent both the compiler and CPU to re-order access.
Name: the Xen project
There is no known mitigation for this flaw apart from applying the patch.
Systems running all versions of Xen are affected by this flaw. Whether a system is vulnerable will depend on the CPU and compiler used to build Xen. For all the systems, the presence and the scope of the vulnerability depends on the precise re-ordering performed by the compiler used to build Xen. x86 systems are only vulnerable if a compiler performs re-ordering. Arm systems will also be vulnerable if the CPU is able to re-order memory access.
This flaw has been rated as having a security impact of Moderate, and is not currently planned to be addressed in future updates of Red Hat Enterprise Linux 5. Red Hat Enterprise Linux 5 is now in Extended Life Phase of the support and maintenance life cycle. For additional information, refer to the Red Hat Enterprise Linux Life Cycle: https://access.redhat.com/support/policy/updates/errata/.
Created xen tracking bugs for this issue:
Affects: fedora-all [bug 1881583]
This bug is now closed. Further updates for individual products will be reflected on the CVE page(s):