Riskcovery

CVE-2026-89568

kho: fix size calculation in kho_preserved_memory_reserve()

State
Published
Severity
Not scored
Published
Sep 11, 2026
Updated
Oct 19, 2026
Reserved
Sep 11, 2026

Read the record on cve.org

Description

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.

Scores

The record has no CVSS score.

Weaknesses

The record names no weakness.

Affected Products

ProductVersions
LinuxLinux
  • fc33e4b44b2717feba2f6f07ce7943a96499c9ec to before 0692a8fdf0222af130c8ea97426f1c3bf3814905Affected
  • fc33e4b44b2717feba2f6f07ce7943a96499c9ec to before 42a6f03cf352eb6e6dbeef95e75e686f4cdb9bd1Affected
  • fc33e4b44b2717feba2f6f07ce7943a96499c9ec to before 3a0b8fa2eb36afc88b62a95f33f0c77c71fa5dedAffected
LinuxLinux
  • 6.16Affected
  • before 6.16Not affected
  • 6.18.57 through 6.18.*Not affected
  • 7.2.4 through 7.2.*Not affected
  • 7.3 and laterNot affected

References

Every record here comes from the CVE Program’s CVE List. © 1999–2026 The MITRE Corporation. CVE is a registered trademark of The MITRE Corporation. The records are reproduced under the CVE Program terms of use.