Riskcovery

CVE-2026-89593

hugetlb: only adjust reservation during unmapping if mapcount is 0

State
Published
Severity
7.1 High
Published
Sep 11, 2026
Updated
Oct 19, 2026
Reserved
Sep 11, 2026

Read the record on cve.org

Description

In the Linux kernel, the following vulnerability has been resolved:

hugetlb: only adjust reservation during unmapping if mapcount is 0

Since df7a6d1f6405, __unmap_hugepage_range can adjust reservations. In the case of folio mapped in both a parent and a child, if the parent unmaps the range first, the reservation adjustment will result in an underflow of the reserved count. Once the child unmaps the range, the count is restored. Change __unmap_hugepage_range() to check the mapcount before adjusting the reservation.

Scores

CVSSScoreVectorSource
3.17.1 HighCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:HLinux

Weaknesses

The record names no weakness.

Affected Products

ProductVersions
LinuxLinux
  • df7a6d1f64056aec572162c5d35ed9ff86ece6f3 to before b0b1b9ca80b795ed2223e76dd787db7067121fb9Affected
  • df7a6d1f64056aec572162c5d35ed9ff86ece6f3 to before a3c65af20cceb7f997847727636b4017326f845dAffected
  • df7a6d1f64056aec572162c5d35ed9ff86ece6f3 to before 0f001491e5a2ec69aa9d5dd6b799e5742245f9eaAffected
  • df7a6d1f64056aec572162c5d35ed9ff86ece6f3 to before 5120b1e048d48596ffaec1a8412012a91adba73bAffected
LinuxLinux
  • 6.9Affected
  • before 6.9Not affected
  • 6.12.110 through 6.12.*Not affected
  • 6.18.50 through 6.18.*Not affected
  • 7.2.4 through 7.2.*Not affected
  • 7.3 and laterNot affected

References

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