CVE-2026-89568

Name of the Vulnerable Software and Affected Versions Linux kernel (affected versions not specified)

Description An issue exists in the kho preserved memory reserve() function where the size of a preservation is calculated using a 32-bit integer shift operation 1 << (order + PAGE SHIFT). Because the constant 1 is treated as a 32-bit integer, it can only be shifted by up to 31 bits, limiting the calculation to preservations up to 2 GiB. When preservations larger than 2 GiB are requested—which is possible via the kho preserve pages() function used by memblock reserve mem—it results in undefined behavior.

Recommendations Update the Linux kernel to a version where the kho preserved memory reserve() function uses 1UL for the shifting operation to ensure correct size calculations for preservations exceeding 2 GiB.