CVE-2026-89568
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 versions
Linux kernel versions
6.16
and later are affected. Fixed in
7.2.4,
7.3-rc1
and their respective stable series.
References
2 totalFrequently asked questions
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What is CVE-2026-89568?
CVE-2026-89568 is a unscored severity Linux kernel vulnerability . It affects Linux kernel versions from 6.16 onward and has been patched in 7.2.4 and 7.3-rc1. CVE-2026-89568 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.
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Is there a patch available for CVE-2026-89568?
Yes. CVE-2026-89568 has been patched. Fixed versions include 7.2.4 and 7.3-rc1. If you are running Linux kernel 6.16 or later up to the fix versions, apply the relevant patch for your kernel branch.
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Is CVE-2026-89568 actively exploited?
No. CVE-2026-89568 has not been confirmed as actively exploited. It is not listed in the CISA Known Exploited Vulnerabilities (KEV) catalog.