[alsa-devel] [PATCH] ASoC: amd: Fix potential NULL pointer dereference

[Gustavo A. R. Silva]

Check return value from call to devm_kzalloc() in order to prevent a
potential NULL pointer dereference.

Also, notice that it makes no sense to allocate any resources if
res = platform_get_resource(pdev, IORESOURCE_MEM, 0); fails,
so move the call to devm_kzalloc() below the mentioned code.

Lastly, improve the use of sizeof in the call to devm_kzalloc() by
changing it from sizeof(struct i2s_dev_data) to sizeof(*adata)

This issue was detected with the help of Coccinelle.

Fixes: ac289c7ec0bc ("ASoC: amd: add ACP3x PCM platform driver")
Cc: stable at vger.kernel.org
Signed-off-by: Gustavo A. R. Silva <gustavo at embeddedor.com>
---
 sound/soc/amd/raven/acp3x-pcm-dma.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/sound/soc/amd/raven/acp3x-pcm-dma.c b/sound/soc/amd/raven/acp3x-pcm-dma.c
index 022a8912c8a2..3d58338fa3cf 100644
--- a/sound/soc/amd/raven/acp3x-pcm-dma.c
+++ b/sound/soc/amd/raven/acp3x-pcm-dma.c
@@ -611,14 +611,16 @@ static int acp3x_audio_probe(struct platform_device *pdev)
 	}
 	irqflags = *((unsigned int *)(pdev->dev.platform_data));
 
-	adata = devm_kzalloc(&pdev->dev, sizeof(struct i2s_dev_data),
-			     GFP_KERNEL);
 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 	if (!res) {
 		dev_err(&pdev->dev, "IORESOURCE_IRQ FAILED\n");
 			return -ENODEV;
 	}
 
+	adata = devm_kzalloc(&pdev->dev, sizeof(*adata), GFP_KERNEL);
+	if (!adata)
+		return -ENOMEM;
+
 	adata->acp3x_base = devm_ioremap(&pdev->dev, res->start,
 					 resource_size(res));
 
-- 
2.20.1