CVE-2026-98854of/overlay: only treat a positive changeset id as registered

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.

Affected packages & fixed versions

Affected products (as reported)

References

• https://git.kernel.org/stable/c/7af5d66d0514b8f1d759d0e32b9d4c5d26263e4a
• https://git.kernel.org/stable/c/71065f3d6864a101b77e7af84566757c4df415a0
• https://git.kernel.org/stable/c/cc688475c56d34a2b584141f9544cbe23360080d
• https://git.kernel.org/stable/c/c08a54df9d33dcd6ff089adc9434b2c008af3a39
• https://git.kernel.org/stable/c/0d1525fdcd3355672b7485d61e55df6824ab5ad1
• https://git.kernel.org/stable/c/c875407c34dadaef0599834ad9c815f4c9f50d15
• https://git.kernel.org/stable/c/44081d708b5b885487bac792db78324b7b4c267d