Re: [PATCH v2 0/2] of: phandle_cache, fix refcounts, remove stale entry

From: Rob Herring
Date: Tue Dec 18 2018 - 10:43:23 EST

On Mon, Dec 17, 2018 at 1:56 AM <frowand.list@xxxxxxxxx> wrote:
> From: Frank Rowand <frank.rowand@xxxxxxxx>
> Non-overlay dynamic devicetree node removal may leave the node in
> the phandle cache. Subsequent calls to of_find_node_by_phandle()
> will incorrectly find the stale entry. This bug exposed the foloowing
> phandle cache refcount bug.
> The refcount of phandle_cache entries is not incremented while in
> the cache, allowing use after free error after kfree() of the
> cached entry.
> Changes since v1:
> - make __of_free_phandle_cache() static
> - add WARN_ON(1) for unexpected condition in of_find_node_by_phandle()
> Frank Rowand (2):
> of: of_node_get()/of_node_put() nodes held in phandle cache
> of: __of_detach_node() - remove node from phandle cache

I'll send this to Linus this week if I get a tested by. Otherwise, it
will go in for 4.21.