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.