[PATCH] sound: soc: davinci - Fix possible NULL derefrence.

[PATCH] sound: soc: davinci - Fix possible NULL derefrence.

[Shailendra Verma]

of_match_device could return NULL, and so can cause a NULL
pointer dereference later.

Signed-off-by: Shailendra Verma <shailendra.v@samsung.com>
---
 sound/soc/davinci/davinci-evm.c |   13 ++++++++++---
 1 file changed, 10 insertions(+), 3 deletions(-)

diff --git a/sound/soc/davinci/davinci-evm.c b/sound/soc/davinci/davinci-evm.c
index 731fb0d..7a369e0 100644
--- a/sound/soc/davinci/davinci-evm.c
+++ b/sound/soc/davinci/davinci-evm.c
@@ -358,13 +358,20 @@ static int evm_aic3x_init(struct snd_soc_pcm_runtime *rtd)
 static int davinci_evm_probe(struct platform_device *pdev)
 {
 	struct device_node *np = pdev->dev.of_node;
-	const struct of_device_id *match =
-		of_match_device(of_match_ptr(davinci_evm_dt_ids), &pdev->dev);
-	struct snd_soc_dai_link *dai = (struct snd_soc_dai_link *) match->data;
+	const struct of_device_id *match;
+	struct snd_soc_dai_link *dai;
 	struct snd_soc_card_drvdata_davinci *drvdata = NULL;
 	struct clk *mclk;
 	int ret = 0;
 
+	match = of_match_device(of_match_ptr(davinci_evm_dt_ids), &pdev->dev);
+	if (!match) {
+		dev_err(&pdev->dev, "Error: No device match found\n");
+		return -ENODEV;
+	}
+
+	dai = (struct snd_soc_dai_link *) match->data;
+
 	evm_soc_card.dai_link = dai;
 
 	dai->codec_of_node = of_parse_phandle(np, "ti,audio-codec", 0);
-- 
1.7.9.5

Re: [PATCH] sound: soc: davinci - Fix possible NULL derefrence.

[Mark Brown]

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On Fri, Jan 27, 2017 at 04:40:57PM +0530, Shailendra Verma wrote:
> of_match_device could return NULL, and so can cause a NULL
> pointer dereference later.

It would be worth explaining how the device can instantiate with no
match...

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Re: [PATCH] sound: soc: davinci - Fix possible NULL derefrence.

[Mark Brown]

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On Fri, Jan 27, 2017 at 04:40:57PM +0530, Shailendra Verma wrote:
> of_match_device could return NULL, and so can cause a NULL
> pointer dereference later.

Oh, and:

Please submit patches using subject lines reflecting the style for the
subsystem.  This makes it easier for people to identify relevant
patches.  Look at what existing commits in the area you're changing are
doing and make sure your subject lines visually resemble what they're
doing.

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Applied "ASoC: davinci - Fix possible NULL derefrence." to the asoc tree

[Mark Brown]

The patch

   ASoC: davinci - Fix possible NULL derefrence.

has been applied to the asoc tree at

   git://git.kernel.org/pub/scm/linux/kernel/git/broonie/sound.git 

All being well this means that it will be integrated into the linux-next
tree (usually sometime in the next 24 hours) and sent to Linus during
the next merge window (or sooner if it is a bug fix), however if
problems are discovered then the patch may be dropped or reverted.  

You may get further e-mails resulting from automated or manual testing
and review of the tree, please engage with people reporting problems and
send followup patches addressing any issues that are reported if needed.

If any updates are required or you are submitting further changes they
should be sent as incremental updates against current git, existing
patches will not be replaced.

Please add any relevant lists and maintainers to the CCs when replying
to this mail.

Thanks,
Mark

>From 3f81d9aa80ae4b513416440e416a6486ef2ad817 Mon Sep 17 00:00:00 2001
From: Shailendra Verma <shailendra.v@samsung.com>
Date: Fri, 27 Jan 2017 16:40:57 +0530
Subject: [PATCH] ASoC: davinci - Fix possible NULL derefrence.

of_match_device could return NULL, and so can cause a NULL
pointer dereference later.

Signed-off-by: Shailendra Verma <shailendra.v@samsung.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
---
 sound/soc/davinci/davinci-evm.c | 13 ++++++++++---
 1 file changed, 10 insertions(+), 3 deletions(-)

diff --git a/sound/soc/davinci/davinci-evm.c b/sound/soc/davinci/davinci-evm.c
index 731fb0d86c6a..7a369e0f2093 100644
--- a/sound/soc/davinci/davinci-evm.c
+++ b/sound/soc/davinci/davinci-evm.c
@@ -358,13 +358,20 @@ static struct snd_soc_card evm_soc_card = {
 static int davinci_evm_probe(struct platform_device *pdev)
 {
 	struct device_node *np = pdev->dev.of_node;
-	const struct of_device_id *match =
-		of_match_device(of_match_ptr(davinci_evm_dt_ids), &pdev->dev);
-	struct snd_soc_dai_link *dai = (struct snd_soc_dai_link *) match->data;
+	const struct of_device_id *match;
+	struct snd_soc_dai_link *dai;
 	struct snd_soc_card_drvdata_davinci *drvdata = NULL;
 	struct clk *mclk;
 	int ret = 0;
 
+	match = of_match_device(of_match_ptr(davinci_evm_dt_ids), &pdev->dev);
+	if (!match) {
+		dev_err(&pdev->dev, "Error: No device match found\n");
+		return -ENODEV;
+	}
+
+	dai = (struct snd_soc_dai_link *) match->data;
+
 	evm_soc_card.dai_link = dai;
 
 	dai->codec_of_node = of_parse_phandle(np, "ti,audio-codec", 0);
-- 
2.11.0