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CVE-2025-22015

mm/migrate: fix shmem xarray update during migration

HIGH 7.8

At a glance

Source
NVD
EPSS
EPSS 0.21 % · percentile 12 ()
State
PUBLISHED
Published
Updated
Assigner
Linux
NVD status
Modified

Description

In the Linux kernel, the following vulnerability has been resolved: mm/migrate: fix shmem xarray update during migration A shmem folio can be either in page cache or in swap cache, but not at the same time. Namely, once it is in swap cache, folio->mapping should be NULL, and the folio is no longer in a shmem mapping. In __folio_migrate_mapping(), to determine the number of xarray entries to update, folio_test_swapbacked() is used, but that conflates shmem in page cache case and shmem in swap cache case. It leads to xarray multi-index entry corruption, since it turns a sibling entry to a normal entry during xas_store() (see [1] for a userspace reproduction). Fix it by only using folio_test_swapcache() to determine whether xarray is storing swap cache entries or not to choose the right number of xarray entries to update. [1] https://lore.kernel.org/linux-mm/Z8idPCkaJW1IChjT@casper.infradead.org/ Note: In __split_huge_page(), folio_test_anon() && folio_test_swapcache() is used to get swap_cache address space, but that ignores the shmem folio in swap cache case. It could lead to NULL pointer dereferencing when a in-swap-cache shmem folio is split at __xa_store(), since !folio_test_anon() is true and folio->mapping is NULL. But fortunately, its caller split_huge_page_to_list_to_order() bails out early with EBUSY when folio->mapping is NULL. So no need to take care of it here.

Weaknesses (CWE)

  • CWE-476 — NULL Pointer Dereference

References

Scores

VersionScoreVectorScored by
CVSS 3.1HIGH 7.8CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:HLinux
CVSS 3.1HIGH 7.8CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:HNVD · 416baaa9-dc9f-4396-8d5f-8c081fb06d67 (Secondary)
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)

European references

CERT-FR advisories

Affected configurations (NVD CPE)

Affected products

ProductVersions
Linux · Linuxaffected be72d197b2281e2ee3f28017fc9be1ab17e26d16 < 49100c0b070e900f87c8fac3be9b9ef8a30fa673 ; affected 07550b1461d4d0499165e7d6f7718cfd0e440427 < 29124ae980e2860f0eec7355949d3d3292ee81da ; affected fc346d0a70a13d52fe1c4bc49516d83a42cd7c4c < c057ee03f751d6cecf7ee64f52f6545d94082aaa ; affected fc346d0a70a13d52fe1c4bc49516d83a42cd7c4c < 75cfb92eb63298d717b6b0118f91ba12c4fcfeb5 ; affected fc346d0a70a13d52fe1c4bc49516d83a42cd7c4c < 60cf233b585cdf1f3c5e52d1225606b86acd08b0 ; affected 6.1.71 < 6.1.132
Linux · Linuxaffected 6.7 ; unaffected 0 < 6.7 ; unaffected 6.1.132 ≤ 6.1.* ; unaffected 6.6.85 ≤ 6.6.* ; unaffected 6.12.21 ≤ 6.12.* ; unaffected 6.13.9 ≤ 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