CVE-2022-48700

Name of the Vulnerable Software and Affected Versions: Linux kernel (affected versions not specified)

Description: The issue is related to a reference count leak on the zero page in the Linux kernel's vfio/type1 component. This leak occurs because the page is handled as an invalid or reserved page after the reference is incremented via pin user pages remote(), and it is not accounted against the user or unpinned by put pfn(). Introducing special zero page handling in put pfn() could resolve the leak, but without accounting for the zero page, a single user could still create enough mappings to generate a reference count overflow. The zero page is always resident, so there is no reason to keep it pinned. A loop has been added to walk pages returned from pin user pages remote() and unpin any zero pages.

Recommendations: At the moment, there is no information about a newer version that contains a fix for this vulnerability.