[PATCH AUTOSEL 5.2 005/123] ASoC: audio-graph-card: fix an use-after-free in graph_get_dai_id()

Sasha Levin
2019-08-14T02:40:14Z

From: Wen Yang <wen.yang99@zte.com.cn>

[ Upstream commit c152f8491a8d9a4b25afd65a86eb5e55e2a8c380 ]

After calling of_node_put() on the node variable, it is still being
used, which may result in use-after-free.
Fix this issue by calling of_node_put() after the last usage.

Fixes: a0c426fe1433 ("ASoC: simple-card-utils: check "reg" property on asoc_simple_card_get_dai_id()")
Link: https://lore.kernel.org/r/1562743509-30496-5-git-send-email-wen.yang99@zte.com.cn
Signed-off-by: Wen Yang <wen.yang99@zte.com.cn>
Acked-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
sound/soc/generic/audio-graph-card.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/sound/soc/generic/audio-graph-card.c b/sound/soc/generic/audio-graph-card.c
index d5188a179378f..a681ea443fc16 100644
--- a/sound/soc/generic/audio-graph-card.c
+++ b/sound/soc/generic/audio-graph-card.c
@@ -63,6 +63,7 @@ static int graph_get_dai_id(struct device_node *ep)
struct device_node *endpoint;
struct of_endpoint info;
int i, id;
+ u32 *reg;
int ret;

/* use driver specified DAI ID if exist */
@@ -83,8 +84,9 @@ static int graph_get_dai_id(struct device_node *ep)
return info.id;

node = of_get_parent(ep);
+ reg = of_get_property(node, "reg", NULL);
of_node_put(node);
- if (of_get_property(node, "reg", NULL))
+ if (reg)
return info.port;
}
node = of_graph_get_port_parent(ep);
--
2.20.1