userfaultfd: fix a crash in UFFDIO_MOVE when PMD is a migration entry
In the Linux kernel, the following vulnerability has been resolved: userfaultfd: fix a crash in UFFDIO_MOVE when PMD is a migration entry When UFFDIO_MOVE encounters a migration PMD entry, it proceeds with obtaining a folio and accessing it even though the entry is swp_entry_t. Add the missing check and let split_huge_pmd() handle migration entries. While at it also remove unnecessary folio check. [[email protected]: remove extra folio check, per David]
02 / AFFECTED SOFTWARE
Affected packages
03 / CONNECTIONS
Connected vulnerabilities
04 / EVIDENCE
Source records
In the Linux kernel, the following vulnerability has been resolved: userfaultfd: fix a crash in UFFDIO_MOVE when PMD is a migration entry When UFFDIO_MOVE encounters a migration PMD entry, it proceeds with obtaining a folio and accessing it even though the entry is swp_entry_t. Add the missing check and let split_huge_pmd() handle migration entries. While at it also remove unnecessary folio check. [[email protected]: remove extra folio check, per David]
05 / REFERENCES
Further evidence
- https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
- https://git.kernel.org/stable/c/1202abad7a7ccd28c426d2844771a387b07629a4
- https://git.kernel.org/stable/c/7f1101a0a181243ad587ececdffc4845f035549f
- https://git.kernel.org/stable/c/aba6faec0103ed8f169be8dce2ead41fcb689446
- https://git.kernel.org/stable/c/bb81c18dbd42650c844e160cafa7cbb20243a96a
- https://github.com/CVEProject/cvelistV5/tree/main/cves/2025/38xxx/CVE-2025-38686.json
- https://nvd.nist.gov/vuln/detail/CVE-2025-38686