dt: protect against NULL matches passed to of_match_node()

There are a few use cases where it is convenient to pass NULL to
of_match_node() and have it fail gracefully.  The patch adds a null
check to the beginning so taht it does so.

Signed-off-by: Grant Likely <grant.likely@secretlab.ca>

1 files changed, 3 insertions, 0 deletions

diff --git a/drivers/of/base.c b/drivers/of/base.c
index 710b53bfac6..632ebae7f17 100644
--- a/drivers/of/base.c
+++ b/drivers/of/base.c
@@ -496,6 +496,9 @@ EXPORT_SYMBOL(of_find_node_with_property);
 const struct of_device_id *of_match_node(const struct of_device_id *matches,
                                          const struct device_node *node)
 {
+        if (!matches)
+                return NULL;
+
         while (matches->name[0] || matches->type[0] || matches->compatible[0]) {
                 int match = 1;
                 if (matches->name[0])