mm: clear uffd-wp PTE/PMD state on mremap() (Linux Linux)

CVE-2025-21696
MEDIUM 5.5

At a glance

Source
NVD
EPSS
EPSS 0.26 % · percentile 18 ()
State
PUBLISHED
Published
Updated
Assigner
Linux
NVD status
Modified

Description

In the Linux kernel, the following vulnerability has been resolved: mm: clear uffd-wp PTE/PMD state on mremap() When mremap()ing a memory region previously registered with userfaultfd as write-protected but without UFFD_FEATURE_EVENT_REMAP, an inconsistency in flag clearing leads to a mismatch between the vma flags (which have uffd-wp cleared) and the pte/pmd flags (which do not have uffd-wp cleared). This mismatch causes a subsequent mprotect(PROT_WRITE) to trigger a warning in page_table_check_pte_flags() due to setting the pte to writable while uffd-wp is still set. Fix this by always explicitly clearing the uffd-wp pte/pmd flags on any such mremap() so that the values are consistent with the existing clearing of VM_UFFD_WP. Be careful to clear the logical flag regardless of its physical form; a PTE bit, a swap PTE bit, or a PTE marker. Cover PTE, huge PMD and hugetlb paths.

References

Scores

VersionScoreVectorScored by
CVSS 3.1MEDIUM 5.5CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:HCISA-ADP
CVSS 3.1MEDIUM 5.5CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:HNVD · nvd@nist.gov (Primary)
CVSS 3.1MEDIUM 5.5CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:HNVD · 134c704f-9b21-4f2e-91b3-4a467353bcc0 (Secondary)

European references

CERT-FR advisories

Affected configurations (NVD CPE)

Affected products

ProductVersions
Linux · Linuxaffected 63b2d4174c4ad1f40b48d7138e71bcb564c1fe03 < 96fed9f20481d07eba8a7fe93bc77abef178198c ; affected 63b2d4174c4ad1f40b48d7138e71bcb564c1fe03 < 8e2f6ba256dd1e590addc48e6e9577bf39c482f2 ; affected 63b2d4174c4ad1f40b48d7138e71bcb564c1fe03 < 310ac886d68de661c3a334198d8604b722d7fdf8 ; affected 63b2d4174c4ad1f40b48d7138e71bcb564c1fe03 < 0cef0bb836e3cfe00f08f9606c72abd72fe78ca3
Linux · Linuxaffected 5.7 ; unaffected 0 < 5.7 ; unaffected 6.1.191 ≤ 6.1.* ; unaffected 6.6.160 ≤ 6.6.* ; unaffected 6.12.11 ≤ 6.12.* ; unaffected 6.13 ≤ *

Sources

SourceLicence
CVE List (CVEProject cvelistV5)CVE Program Terms of Use
EPSS (FIRST.org)FIRST — attribution requested
ENISA EUVDENISA — reproduction authorised, source acknowledged
CERT-FR (ANSSI)Licence Ouverte / Etalab 2.0
NVD (NIST) via fkie-cad/nvd-json-data-feedsPublic domain — this product uses data from the NVD API but is not endorsed or certified by the NVD