In several functions vcpu_id is used as an offset into rtc_status.dest_map in order to set or clear bits in kernel memory, potentially leading to out-of-bound access when vcpu_id is larger than 255.
An unprivileged local user could use this flaw to elevate their privileges on the system.
Acknowledgements:
Red Hat would like to thank Andrew Honig of Google for reporting this issue.
Statement:
Not vulnerable.
This issue did not affect the versions of kvm packages as shipped with Red Hat Enterprise Linux 5. This issue did not affect the versions of Linux kernel as shipped with Red Hat Enterprise 6.
This issue did not affect the versions of Linux kernel as shipped with Red Hat Enterprise MRG 2 as they did not provide support for the KVM subsystem.