Bug 2525407 (CVE-2026-80723)

Summary: CVE-2026-80723 kernel: of: reserved_mem: prevent OOB when too many dynamic regions are defined
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security DevOps Team <prodsec-dev>
Status: NEW --- QA Contact:
Severity: medium Docs Contact:
Priority: medium    
Version: unspecifiedCC: rhel-process-autobot, watson-tool-maintainers
Target Milestone: ---Keywords: Security
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Hardware: All   
OS: Linux   
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A flaw was found in the `of: reserved_mem` component of the Linux kernel. When the device tree defines more dynamic regions than the `MAX_RESERVED_REGIONS` array can hold, the `fdt_scan_reserved_mem()` function performs an out-of-bounds write. This vulnerability can lead to memory corruption, potentially impacting system stability or allowing for further exploitation.
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Description OSIDB Bzimport 2026-08-28 07:43:26 UTC 
In the Linux kernel, the following vulnerability has been resolved:

of: reserved_mem: prevent OOB when too many dynamic regions are defined

On boot, fdt_scan_reserved_mem() saves each dynamically-placed
/reserved-memory subnode into a local array of size
MAX_RESERVED_REGIONS.

If the device tree defines more than MAX_RESERVED_REGIONS
dynamically-placed regions, fdt_scan_reserved_mem() writes past the
end of the local array.

Add a bounds check that logs an error and skips the excess regions,
restoring the original behavior.
Comment 1 gkamathe 2026-08-31 10:53:04 UTC 
Upstream advisory:
https://lore.kernel.org/linux-cve-announce/2026082811-CVE-2026-80723-2526@gregkh/T