CVE Catalog

CVE-2026-89593

HighCVSS 7.1
Published: Updated: Translated: NVD NIST

Exploitation Probability (EPSS)

Low risk
0.12%

2th percentile - higher than 2% of all known CVEs

Summary

In the Linux kernel's hugetlb subsystem, __unmap_hugepage_range can adjust reservations since commit df7a6d1f6405. When a folio is mapped in both a parent and a child, and the parent unmaps the range first, the reservation adjustment causes an underflow of the reserved count. Once the child unmaps the range, the count is restored. The fix checks the mapcount before adjusting the reservation.

Risk Assessment

Reservation count underflow can lead to improper memory management, potential kernel crashes, or huge page allocation issues. This may affect system stability and availability.

Recommendation

Update the Linux kernel to a version containing the fix that checks the mapcount before adjusting the reservation in __unmap_hugepage_range().

Other vulnerabilities in Linux kernel

See all
Original NVD description (English source)

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.

Vulnerability data from NVD (NIST) · CISA KEV · EPSS