CVE-2023-53856 of: overlay: Call of_changeset_init() early
A NULL pointer dereference in the Linux kernel's device tree overlay code can cause a system crash when an overlay application fails.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2023-53856?
CVE-2023-53856 is a vulnerability in Linux, published on 9 Dec 2025. It can only be exploited from the same machine or local network, with no action from the victim.
Official description
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.
Which versions are affected by CVE-2023-53856?
How do I fix CVE-2023-53856?
Apply the vendor's patch.
Is CVE-2023-53856 being exploited?
There is no known exploitation of CVE-2023-53856 in the wild and no public exploit code.
Sources
Also known as BELL-CVE-2023-53856, DEBIAN-CVE-2023-53856, GHSA-v9q6-qjf3-fr39, ROOT-OS-DEBIAN-11-CVE-2023-53856, UBUNTU-CVE-2023-53856.