ASoC: simple-card-utils: Propagate errors on too many links

The DAI counting code doesn't propagate errors when the number of
maximum links is exceeded, which causes subsequent initialization code
to continue to run and that eventually leads to memory corruption with
the code trying to access memory that is out of bounds.

Fix this by propagating errors when the maximum number of links is
reached, which ensures that the driver fails to load and prevents the
memory corruption.

Fixes: f2138aed231c ("ASoC: simple-card-utils: enable flexible CPU/Codec/Platform")
Signed-off-by: Thierry Reding <treding@nvidia.com>
Link: https://lore.kernel.org/r/20210416071147.2149109-1-thierry.reding@gmail.com
Reviewed-by: Jon Hunter <jonathanh@nvidia.com>
Tested-by: Jon Hunter <jonathanh@nvidia.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

diff --git a/sound/soc/generic/audio-graph-card.c b/sound/soc/generic/audio-graph-card.c
index 36b2ad7dd283bf59f2852bfeb89db91d6326db6c..080c1a22bfc2fc1af3b0d1a3dfb5a247749f576c 100644 (file)
--- a/sound/soc/generic/audio-graph-card.c
+++ b/sound/soc/generic/audio-graph-card.c
@@ -542,8 +542,8 @@ static int graph_for_each_link(struct asoc_simple_priv *priv,
        return ret;
 }
 
-static void graph_get_dais_count(struct asoc_simple_priv *priv,
-                                struct link_info *li);
+static int graph_get_dais_count(struct asoc_simple_priv *priv,
+                               struct link_info *li);
 
 int audio_graph_parse_of(struct asoc_simple_priv *priv, struct device *dev)
 {
@@ -555,7 +555,10 @@ int audio_graph_parse_of(struct asoc_simple_priv *priv, struct device *dev)
        card->dev = dev;
 
        memset(&li, 0, sizeof(li));
-       graph_get_dais_count(priv, &li);
+       ret = graph_get_dais_count(priv, &li);
+       if (ret < 0)
+               return ret;
+
        if (!li.link)
                return -EINVAL;
 
@@ -660,8 +663,8 @@ static int graph_count_dpcm(struct asoc_simple_priv *priv,
        return 0;
 }
 
-static void graph_get_dais_count(struct asoc_simple_priv *priv,
-                                struct link_info *li)
+static int graph_get_dais_count(struct asoc_simple_priv *priv,
+                               struct link_info *li)
 {
        /*
         * link_num :   number of links.
@@ -709,9 +712,9 @@ static void graph_get_dais_count(struct asoc_simple_priv *priv,
         *      => 4 DAIs  = 2xCPU + 2xCodec
         *      => 1 ccnf  = 1xdummy-Codec
         */
-       graph_for_each_link(priv, li,
-                           graph_count_noml,
-                           graph_count_dpcm);
+       return graph_for_each_link(priv, li,
+                                  graph_count_noml,
+                                  graph_count_dpcm);
 }
 
 int audio_graph_card_probe(struct snd_soc_card *card)

diff --git a/sound/soc/generic/simple-card.c b/sound/soc/generic/simple-card.c
index 5a686f82d1b46ee127cb859839414abceac7ec76..e05539b5f997b9c9c08547b1ffa4bb4aad85a668 100644 (file)
--- a/sound/soc/generic/simple-card.c
+++ b/sound/soc/generic/simple-card.c
@@ -524,8 +524,8 @@ static int simple_count_dpcm(struct asoc_simple_priv *priv,
        return 0;
 }
 
-static void simple_get_dais_count(struct asoc_simple_priv *priv,
-                                 struct link_info *li)
+static int simple_get_dais_count(struct asoc_simple_priv *priv,
+                                struct link_info *li)
 {
        struct device *dev = simple_priv_to_dev(priv);
        struct device_node *top = dev->of_node;
@@ -582,12 +582,12 @@ static void simple_get_dais_count(struct asoc_simple_priv *priv,
                li->num[0].platforms    = 1;
 
                li->link = 1;
-               return;
+               return 0;
        }
 
-       simple_for_each_link(priv, li,
-                            simple_count_noml,
-                            simple_count_dpcm);
+       return simple_for_each_link(priv, li,
+                                   simple_count_noml,
+                                   simple_count_dpcm);
 }
 
 static int simple_soc_probe(struct snd_soc_card *card)
@@ -626,7 +626,10 @@ static int asoc_simple_probe(struct platform_device *pdev)
        card->probe             = simple_soc_probe;
 
        memset(&li, 0, sizeof(li));
-       simple_get_dais_count(priv, &li);
+       ret = simple_get_dais_count(priv, &li);
+       if (ret < 0)
+               return ret;
+
        if (!li.link)
                return -EINVAL;