From 5801169a2ed20003f771acecf3ac00574cf10a38 Mon Sep 17 00:00:00 2001 From: Frank Rowand Date: Tue, 18 Dec 2018 11:40:03 -0800 Subject: of: __of_detach_node() - remove node from phandle cache 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. Remove the node from the cache. Add paranoia checks in of_find_node_by_phandle() as a second level of defense (do not return cached node if detached, do not add node to cache if detached). Fixes: 0b3ce78e90fc ("of: cache phandle nodes to reduce cost of of_find_node_by_phandle()") Reported-by: Michael Bringmann Cc: stable@vger.kernel.org # v4.17+ Signed-off-by: Frank Rowand Signed-off-by: Rob Herring --- drivers/of/dynamic.c | 3 +++ 1 file changed, 3 insertions(+) (limited to 'drivers/of/dynamic.c') diff --git a/drivers/of/dynamic.c b/drivers/of/dynamic.c index b4e5b90cb314..a09c1c3cf831 100644 --- a/drivers/of/dynamic.c +++ b/drivers/of/dynamic.c @@ -277,6 +277,9 @@ void __of_detach_node(struct device_node *np) } of_node_set_flag(np, OF_DETACHED); + + /* race with of_find_node_by_phandle() prevented by devtree_lock */ + __of_free_phandle_cache_entry(np->phandle); } /** -- cgit