[PATCH] pwm - Fix possible NULL derefrence.

[PATCH] pwm - 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>
---
 drivers/pwm/pwm-sun4i.c |    4 ++++
 drivers/pwm/pwm-tegra.c |    5 +++++
 2 files changed, 9 insertions(+)

diff --git a/drivers/pwm/pwm-sun4i.c b/drivers/pwm/pwm-sun4i.c
index b0803f6..9b5c6fe 100644
--- a/drivers/pwm/pwm-sun4i.c
+++ b/drivers/pwm/pwm-sun4i.c
@@ -321,6 +321,10 @@ static int sun4i_pwm_probe(struct platform_device *pdev)
 	const struct of_device_id *match;
 
 	match = of_match_device(sun4i_pwm_dt_ids, &pdev->dev);
+	if (!match) {
+		dev_err(&pdev->dev, "Error: No device match found\n");
+		return -ENODEV;
+	}
 
 	pwm = devm_kzalloc(&pdev->dev, sizeof(*pwm), GFP_KERNEL);
 	if (!pwm)
diff --git a/drivers/pwm/pwm-tegra.c b/drivers/pwm/pwm-tegra.c
index e464784..a5eb224 100644
--- a/drivers/pwm/pwm-tegra.c
+++ b/drivers/pwm/pwm-tegra.c
@@ -185,6 +185,11 @@ static int tegra_pwm_probe(struct platform_device *pdev)
 		return -ENOMEM;
 
 	pwm->soc = of_device_get_match_data(&pdev->dev);
+	if (!pwm->soc) {
+		dev_err(&pdev->dev, "no device match found\n");
+		return -ENODEV;
+	}
+
 	pwm->dev = &pdev->dev;
 
 	r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
-- 
1.7.9.5

Re: [PATCH] pwm - Fix possible NULL derefrence.

[Thierry Reding]

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On Mon, Jan 30, 2017 at 10:22:33AM +0530, Shailendra Verma wrote:
> of_match_device could return NULL, and so can cause a NULL
> pointer dereference later.
> 
> Signed-off-by: Shailendra Verma <shailendra.v@samsung.com>
> ---
>  drivers/pwm/pwm-sun4i.c |    4 ++++
>  drivers/pwm/pwm-tegra.c |    5 +++++
>  2 files changed, 9 insertions(+)

Both of these drivers will only run on purely OF systems, so this check
is unnecessary.

Thierry

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