CVE-2025-38686

Summary

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.

[surenb@google.com: remove extra folio check, per David]

Affected Software

VendorProductVersion RangeStatus
LinuxLinuxadef440691bab824e39c1b17382322d195e1fab0 < bb81c18dbd42650c844e160cafa7cbb20243a96aaffected
LinuxLinuxadef440691bab824e39c1b17382322d195e1fab0 < 1202abad7a7ccd28c426d2844771a387b07629a4affected
LinuxLinuxadef440691bab824e39c1b17382322d195e1fab0 < 7f1101a0a181243ad587ececdffc4845f035549faffected
LinuxLinuxadef440691bab824e39c1b17382322d195e1fab0 < aba6faec0103ed8f169be8dce2ead41fcb689446affected
LinuxLinux6.8affected
LinuxLinux0 < 6.8unaffected
LinuxLinux6.12.43 <= 6.12.*unaffected
LinuxLinux6.15.11 <= 6.15.*unaffected
LinuxLinux6.16.2 <= 6.16.*unaffected
LinuxLinux6.17 <= *unaffected

Weaknesses

References