Bug 2420314 (CVE-2023-53856)

Summary: CVE-2023-53856 kernel: of: overlay: Call of_changeset_init() early
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security DevOps Team <prodsec-dev>
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Version: unspecifiedKeywords: Security
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OS: Linux   
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Description OSIDB Bzimport 2025-12-09 02:02:18 UTC 
In the Linux kernel, the following vulnerability has been resolved:

of: overlay: Call of_changeset_init() early

When of_overlay_fdt_apply() fails, the changeset may be partially
applied, and the caller is still expected to call of_overlay_remove() to
clean up this partial state.

However, of_overlay_apply() calls of_resolve_phandles() before
init_overlay_changeset().  Hence if the overlay fails to apply due to an
unresolved symbol, the overlay_changeset.cset.entries list is still
uninitialized, and cleanup will crash with a NULL-pointer dereference in
overlay_removal_is_ok().

Fix this by moving the call to of_changeset_init() from
init_overlay_changeset() to of_overlay_fdt_apply(), where all other
early initialization is done.
Comment 1 Alexander B 2025-12-10 02:14:11 UTC 
Upstream advisory:
https://lore.kernel.org/linux-cve-announce/2025120903-CVE-2023-53856-ed42@gregkh/T