CVE-2026-89593
hugetlb: only adjust reservation during unmapping if mapcount is 0
CVSS Score
7.1
EPSS Score
0.0%
EPSS Percentile
0th
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.
| Vendor | linux |
| Product | linux |
| Ecosystems | |
| Industries | Technology |
| Published | Sep 11, 2026 |
| Last Updated | Sep 14, 2026 |
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CVSS v3 Breakdown
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:H Attack Vector
Attack Complexity
Privileges Required
User Interaction
Scope
Confidentiality
Integrity
Availability
Affected Versions
Linux / Linux
df7a6d1f64056aec572162c5d35ed9ff86ece6f3 < b0b1b9ca80b795ed2223e76dd787db7067121fb9 df7a6d1f64056aec572162c5d35ed9ff86ece6f3 < a3c65af20cceb7f997847727636b4017326f845d df7a6d1f64056aec572162c5d35ed9ff86ece6f3 < 0f001491e5a2ec69aa9d5dd6b799e5742245f9ea df7a6d1f64056aec572162c5d35ed9ff86ece6f3 < 5120b1e048d48596ffaec1a8412012a91adba73b
Linux / Linux
6.9
References
git.kernel.org: https://git.kernel.org/stable/c/b0b1b9ca80b795ed2223e76dd787db7067121fb9 git.kernel.org: https://git.kernel.org/stable/c/a3c65af20cceb7f997847727636b4017326f845d git.kernel.org: https://git.kernel.org/stable/c/0f001491e5a2ec69aa9d5dd6b799e5742245f9ea git.kernel.org: https://git.kernel.org/stable/c/5120b1e048d48596ffaec1a8412012a91adba73b