Luis Chamberlain

**Name of the Vulnerable Software and Affected Versions** Linux kernel (affected versions not specified) **Description** The issue is related to the `folio test hugetlb()` function, which can be fooled by a concurrent folio split into returning true for a folio that has never belonged to `hugetlbfs`. This can happen in places like `memory-failure`, `compaction`, and `procfs`, where a speculative reference is not taken. The `PageType` field is available since `hugetlb` pages do not use individual page mapcounts and `page mapcount()` ignores the value in this field. With `CONFIG DEBUG VM` enabled, the current implementation can result in an oops, as reported by Luis, due to `VM BUG ON()` checks added in the `PageHuge()` testing path. **Recommendations** At the moment, there is no information about a newer version that contains a fix for this vulnerability.