CVE-2026-89568: Linux

EPSS: 0.2% chance of exploitation in the next 30 days.

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.

Affected products

• Linux Linux: from 6.16, before 7.2.4 (fixed in 7.2.4)

Published 2026-09-11. Last modified 2026-09-11.