CVE-2023-53205

In the Linux kernel, the following vulnerability has been resolved:

KVM: s390/diag: fix racy access of physical cpu number in diag 9c handler

We do check for target CPU == -1, but this might change at the time we are going to use it. Hold the physical target CPU in a local variable to avoid out-of-bound accesses to the cpu arrays.

This vulnerability is rated Moderate for Red Hat Enterprise Linux on the s390x architecture. The flaw is a race condition in the KVM s390/diag handler that could lead to out-of-bounds access. Triggering this vulnerability requires precise timing and repeated invocations and will most likely result in a denial-of-service. Confidentiality is not impacted as the bug does not directly expose guest or host memory contents. Availability is also highly unlikely to be impacted, though out-of-bounds access could in theory corrupt the kernel or KVM internal state.

The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.