CVE Catalog

CVE-2026-89568

Low risk· EPSS 10%
Published: Updated: Translated: NVD NIST

Exploitation Probability (EPSS)

Low risk
0.21%

10th percentile - higher than 10% of all known CVEs

Summary

In the Linux kernel, kho_preserved_memory_reserve() calculates the preservation size as 1 << (order + PAGE_SHIFT), where '1' is a 32-bit integer, so it can only be shifted by 31 bits. Preservations larger than 2 GiB, obtainable via kho_preserve_pages() used by memblock reserve_mem, trigger undefined behaviour.

Risk Assessment

Incorrect size calculation can lead to undefined kernel behaviour, memory corruption, or system crash for reservations larger than 2 GiB.

Recommendation

Update the Linux kernel to a version where the shift uses 1UL instead of 1.

Related vulnerabilities

Original NVD description (English source)

In the Linux kernel, the following vulnerability has been resolved: kho: fix size calculation in kho_preserved_memory_reserve() kho_preserved_memory_reserve() calculates the size of a preservation by doing 1 << (order + PAGE_SHIFT). Since the '1' is a 32-bit integer, it can only be shifted by 31. That is, it will only work for preservations up to 2 GiB. Larger preservations will trigger undefined behaviour. While preservations larger than 2 GiB can't be obtained via folios currently, they can be obtained via kho_preserve_pages(). For example, memblock reserve_mem uses kho_preserve_pages(). Reservations larger than 2 GiB are valid and will trigger this bug if properly aligned. Fix it by using 1UL for shifting.

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