CVE-2026-98854 of/overlay: only treat a positive changeset id as registered
A null pointer dereference in the Linux kernel's device tree overlay code can cause a system crash when an ID allocation fails.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Not stated
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-98854?
CVE-2026-98854 is a vulnerability in Linux, published on 18 Oct 2026.
Official description
In the Linux kernel, the following vulnerability has been resolved:
of/overlay: only treat a positive changeset id as registered
of_overlay_fdt_apply() stores the idr_alloc() return value in ovcs->id before checking it. On failure the stored id is negative, free_overlay_changeset()'s "if (ovcs->id)" check passes, idr_remove() is called with a negative id and list_del() runs on ovcs->ovcs_list, which is not initialized until after the id allocation. An allocation failure at that point dereferences NULL.
Make free_overlay_changeset() treat only a strict-positive id as registered. The rest of the function already copes with a partially-initialized ovcs, so the error path stays a plain goto err_free_ovcs.
Which versions are affected by CVE-2026-98854?
How do I fix CVE-2026-98854?
Apply the vendor's patch.
Is CVE-2026-98854 being exploited?
There is no known exploitation of CVE-2026-98854 in the wild and no public exploit code.
Sources
Also known as AZL-109332, BELL-CVE-2026-98854, DEBIAN-CVE-2026-98854, GHSA-x4qh-8j3r-qp8v, UBUNTU-CVE-2026-98854.