CVE-2025-37936

Name of the Vulnerable Software and Affected Versions Linux kernel versions prior to the version containing the fix for the issue described, as the specific fixed version is not mentioned.

Description The issue arises when generating the MSR IA32 PEBS ENABLE value for a KVM guest, where the host kernel's masks are consulted without considering the guest's desired PEBS ENABLE value. This can lead to the guest running with PEBS enabled even when it does not intend to use PEBS, resulting in crashes due to a high volume of page faults. The problem is most easily reproduced by running perf kvm top from before a specific commit. The userspace side of perf creates a guest-only PEBS event, which is misconstrued by intel guest get msrs(). Although this could be considered a userspace bug, restricting PEBS to guest-owned events in perf/KVM has no downside.

Recommendations As a temporary workaround, consider disabling the use of PEBS for guest-only events until a patch is available. Restrict access to the perf kvm top command to minimize the risk of exploitation. Avoid using PEBS events in the affected KVM guests until the issue is resolved. At the moment, there is no information about a newer version that contains a fix for this vulnerability.