of/address: Fix of_node memory leak in of_dma_is_coherent

[ Upstream commit a5bea04fcc0b3c0aec71ee1fd58fd4ff7ee36177 ]

Commit dabf6b36b83a ("of: Add OF_DMA_DEFAULT_COHERENT & select it on
powerpc") added a check to of_dma_is_coherent which returns early
if OF_DMA_DEFAULT_COHERENT is enabled. This results in the of_node_put()
being skipped causing a memory leak. Moved the of_node_get() below this
check so we now we only get the node if OF_DMA_DEFAULT_COHERENT is not
enabled.

Fixes: dabf6b36b83a ("of: Add OF_DMA_DEFAULT_COHERENT & select it on powerpc")
Signed-off-by: Evan Nimmo <evan.nimmo@alliedtelesis.co.nz>
Link: https://lore.kernel.org/r/20201110022825.30895-1-evan.nimmo@alliedtelesis.co.nz
Signed-off-by: Rob Herring <robh@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/drivers/of/address.c b/drivers/of/address.c
index da4f7341323f22451c2a1a5eb07bc3cf24832efd..37ac311843090604e3778d7716986b251d638f1b 100644 (file)
--- a/drivers/of/address.c
+++ b/drivers/of/address.c
@@ -1043,11 +1043,13 @@ out:
  */
 bool of_dma_is_coherent(struct device_node *np)
 {
-       struct device_node *node = of_node_get(np);
+       struct device_node *node;
 
        if (IS_ENABLED(CONFIG_OF_DMA_DEFAULT_COHERENT))
                return true;
 
+       node = of_node_get(np);
+
        while (node) {
                if (of_property_read_bool(node, "dma-coherent")) {
                        of_node_put(node);