CVE-2025-38085 (GCVE-0-2025-38085)

Vulnerability from cvelistv5 – Published: 2025-06-28 07:44 – Updated: 2026-05-11 21:20
VLAI
Title
mm/hugetlb: fix huge_pmd_unshare() vs GUP-fast race
Summary
In the Linux kernel, the following vulnerability has been resolved: mm/hugetlb: fix huge_pmd_unshare() vs GUP-fast race huge_pmd_unshare() drops a reference on a page table that may have previously been shared across processes, potentially turning it into a normal page table used in another process in which unrelated VMAs can afterwards be installed. If this happens in the middle of a concurrent gup_fast(), gup_fast() could end up walking the page tables of another process. While I don't see any way in which that immediately leads to kernel memory corruption, it is really weird and unexpected. Fix it with an explicit broadcast IPI through tlb_remove_table_sync_one(), just like we do in khugepaged when removing page tables for a THP collapse.
Severity
No CVSS data available.
Assigner
References
Impacted products
Vendor Product Version
Linux Linux Affected: 39dde65c9940c97fcd178a3d2b1c57ed8b7b68aa , < 952596b08c74e8fe9e2883d1dc8a8f54a37384ec (git)
Affected: 39dde65c9940c97fcd178a3d2b1c57ed8b7b68aa , < a3d864c901a300c295692d129159fc3001a56185 (git)
Affected: 39dde65c9940c97fcd178a3d2b1c57ed8b7b68aa , < b7754d3aa7bf9f62218d096c0c8f6c13698fac8b (git)
Affected: 39dde65c9940c97fcd178a3d2b1c57ed8b7b68aa , < fe684290418ef9ef76630072086ee530b92f02b8 (git)
Affected: 39dde65c9940c97fcd178a3d2b1c57ed8b7b68aa , < 034a52b5ef57c9c8225d94e9067f3390bb33922f (git)
Affected: 39dde65c9940c97fcd178a3d2b1c57ed8b7b68aa , < a6bfeb97941a9187833b526bc6cc4ff5706d0ce9 (git)
Affected: 39dde65c9940c97fcd178a3d2b1c57ed8b7b68aa , < 1013af4f585fccc4d3e5c5824d174de2257f7d6d (git)
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Linux Linux Affected: 2.6.20
Unaffected: 0 , < 2.6.20 (semver)
Unaffected: 5.10.239 , ≤ 5.10.* (semver)
Unaffected: 5.15.186 , ≤ 5.15.* (semver)
Unaffected: 6.1.142 , ≤ 6.1.* (semver)
Unaffected: 6.6.95 , ≤ 6.6.* (semver)
Unaffected: 6.12.35 , ≤ 6.12.* (semver)
Unaffected: 6.15.4 , ≤ 6.15.* (semver)
Unaffected: 6.16 , ≤ * (original_commit_for_fix)
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Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.

Sightings

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Nomenclature

  • Seen: The vulnerability was mentioned, discussed, or observed by the user.
  • Confirmed: The vulnerability has been validated from an analyst's perspective.
  • Published Proof of Concept: A public proof of concept is available for this vulnerability.
  • Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
  • Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
  • Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
  • Not confirmed: The user expressed doubt about the validity of the vulnerability.
  • Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.


Detection rules are retrieved from Rulezet.