mmc: host: dereference null return value
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Message ID 1592885209-25839-1-git-send-email-haibo.chen@nxp.com
State Not Applicable
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Series
  • mmc: host: dereference null return value
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Commit Message

Bough Chen June 23, 2020, 4:06 a.m. UTC
From: Haibo Chen <haibo.chen@nxp.com>

of_match_node() has the opportunity to return NULL, so need to
dereference null return value.
This is reported by Coverity.

Signed-off-by: Haibo Chen <haibo.chen@nxp.com>
---
 drivers/mmc/host/dw_mmc-exynos.c   | 5 +++--
 drivers/mmc/host/dw_mmc-k3.c       | 5 +++--
 drivers/mmc/host/dw_mmc-pltfm.c    | 3 ++-
 drivers/mmc/host/sdhci-of-arasan.c | 2 ++
 4 files changed, 10 insertions(+), 5 deletions(-)

Comments

Adrian Hunter July 1, 2020, 10:33 a.m. UTC | #1
On 23/06/20 7:06 am, haibo.chen@nxp.com wrote:
> From: Haibo Chen <haibo.chen@nxp.com>
> 
> of_match_node() has the opportunity to return NULL, so need to
> dereference null return value.
> This is reported by Coverity.
> 
> Signed-off-by: Haibo Chen <haibo.chen@nxp.com>
> ---
>  drivers/mmc/host/dw_mmc-exynos.c   | 5 +++--
>  drivers/mmc/host/dw_mmc-k3.c       | 5 +++--
>  drivers/mmc/host/dw_mmc-pltfm.c    | 3 ++-
>  drivers/mmc/host/sdhci-of-arasan.c | 2 ++
>  4 files changed, 10 insertions(+), 5 deletions(-)
> 
> diff --git a/drivers/mmc/host/dw_mmc-exynos.c b/drivers/mmc/host/dw_mmc-exynos.c
> index 5e3d95b63676..27ab55abb03f 100644
> --- a/drivers/mmc/host/dw_mmc-exynos.c
> +++ b/drivers/mmc/host/dw_mmc-exynos.c
> @@ -545,12 +545,13 @@ MODULE_DEVICE_TABLE(of, dw_mci_exynos_match);
>  
>  static int dw_mci_exynos_probe(struct platform_device *pdev)
>  {
> -	const struct dw_mci_drv_data *drv_data;
> +	const struct dw_mci_drv_data *drv_data = NULL;
>  	const struct of_device_id *match;
>  	int ret;
>  
>  	match = of_match_node(dw_mci_exynos_match, pdev->dev.of_node);
> -	drv_data = match->data;
> +	if (match)
> +		drv_data = match->data;

Could be 1 line change:

	drv_data = match ? match->data : NULL;

>  
>  	pm_runtime_get_noresume(&pdev->dev);
>  	pm_runtime_set_active(&pdev->dev);
> diff --git a/drivers/mmc/host/dw_mmc-k3.c b/drivers/mmc/host/dw_mmc-k3.c
> index 50977ff18074..e8a148c306b3 100644
> --- a/drivers/mmc/host/dw_mmc-k3.c
> +++ b/drivers/mmc/host/dw_mmc-k3.c
> @@ -451,11 +451,12 @@ MODULE_DEVICE_TABLE(of, dw_mci_k3_match);
>  
>  static int dw_mci_k3_probe(struct platform_device *pdev)
>  {
> -	const struct dw_mci_drv_data *drv_data;
> +	const struct dw_mci_drv_data *drv_data = NULL;
>  	const struct of_device_id *match;
>  
>  	match = of_match_node(dw_mci_k3_match, pdev->dev.of_node);
> -	drv_data = match->data;
> +	if (match)
> +		drv_data = match->data;

Could be 1 line change:

	drv_data = match ? match->data : NULL;

>  
>  	return dw_mci_pltfm_register(pdev, drv_data);
>  }
> diff --git a/drivers/mmc/host/dw_mmc-pltfm.c b/drivers/mmc/host/dw_mmc-pltfm.c
> index 7de37f524a96..d3dcb96efd13 100644
> --- a/drivers/mmc/host/dw_mmc-pltfm.c
> +++ b/drivers/mmc/host/dw_mmc-pltfm.c
> @@ -78,7 +78,8 @@ static int dw_mci_pltfm_probe(struct platform_device *pdev)
>  
>  	if (pdev->dev.of_node) {
>  		match = of_match_node(dw_mci_pltfm_match, pdev->dev.of_node);
> -		drv_data = match->data;
> +		if (match)
> +			drv_data = match->data;
>  	}
>  
>  	return dw_mci_pltfm_register(pdev, drv_data);
> diff --git a/drivers/mmc/host/sdhci-of-arasan.c b/drivers/mmc/host/sdhci-of-arasan.c
> index fb26e743e1fd..f2090f944a0e 100644
> --- a/drivers/mmc/host/sdhci-of-arasan.c
> +++ b/drivers/mmc/host/sdhci-of-arasan.c
> @@ -1520,6 +1520,8 @@ static int sdhci_arasan_probe(struct platform_device *pdev)
>  	const struct sdhci_arasan_of_data *data;
>  
>  	match = of_match_node(sdhci_arasan_of_match, pdev->dev.of_node);
> +	if (match == NULL)

(!match) seems to be preferred over (match == NULL)

> +		return -ENOPARAM;

ENOPARAM is unconventional here.  ENODEV or EINVAL are better

>  	data = match->data;
>  	host = sdhci_pltfm_init(pdev, data->pdata, sizeof(*sdhci_arasan));
>  
>
Marek Szyprowski July 1, 2020, 10:57 a.m. UTC | #2
Hi,

On 23.06.2020 06:06, haibo.chen@nxp.com wrote:
> From: Haibo Chen <haibo.chen@nxp.com>
>
> of_match_node() has the opportunity to return NULL, so need to
> dereference null return value.
> This is reported by Coverity.
>
> Signed-off-by: Haibo Chen <haibo.chen@nxp.com>

There is no point in such check for a NULL. The driver won't be 
instantiated/probed if there is no matching node found first by the 
upper level framework. If you really want to make this code cleaner, 
please change it to use of_device_get_match_data().

> ---
>   drivers/mmc/host/dw_mmc-exynos.c   | 5 +++--
>   drivers/mmc/host/dw_mmc-k3.c       | 5 +++--
>   drivers/mmc/host/dw_mmc-pltfm.c    | 3 ++-
>   drivers/mmc/host/sdhci-of-arasan.c | 2 ++
>   4 files changed, 10 insertions(+), 5 deletions(-)

 > ...

Best regards

Patch
diff mbox series

diff --git a/drivers/mmc/host/dw_mmc-exynos.c b/drivers/mmc/host/dw_mmc-exynos.c
index 5e3d95b63676..27ab55abb03f 100644
--- a/drivers/mmc/host/dw_mmc-exynos.c
+++ b/drivers/mmc/host/dw_mmc-exynos.c
@@ -545,12 +545,13 @@  MODULE_DEVICE_TABLE(of, dw_mci_exynos_match);
 
 static int dw_mci_exynos_probe(struct platform_device *pdev)
 {
-	const struct dw_mci_drv_data *drv_data;
+	const struct dw_mci_drv_data *drv_data = NULL;
 	const struct of_device_id *match;
 	int ret;
 
 	match = of_match_node(dw_mci_exynos_match, pdev->dev.of_node);
-	drv_data = match->data;
+	if (match)
+		drv_data = match->data;
 
 	pm_runtime_get_noresume(&pdev->dev);
 	pm_runtime_set_active(&pdev->dev);
diff --git a/drivers/mmc/host/dw_mmc-k3.c b/drivers/mmc/host/dw_mmc-k3.c
index 50977ff18074..e8a148c306b3 100644
--- a/drivers/mmc/host/dw_mmc-k3.c
+++ b/drivers/mmc/host/dw_mmc-k3.c
@@ -451,11 +451,12 @@  MODULE_DEVICE_TABLE(of, dw_mci_k3_match);
 
 static int dw_mci_k3_probe(struct platform_device *pdev)
 {
-	const struct dw_mci_drv_data *drv_data;
+	const struct dw_mci_drv_data *drv_data = NULL;
 	const struct of_device_id *match;
 
 	match = of_match_node(dw_mci_k3_match, pdev->dev.of_node);
-	drv_data = match->data;
+	if (match)
+		drv_data = match->data;
 
 	return dw_mci_pltfm_register(pdev, drv_data);
 }
diff --git a/drivers/mmc/host/dw_mmc-pltfm.c b/drivers/mmc/host/dw_mmc-pltfm.c
index 7de37f524a96..d3dcb96efd13 100644
--- a/drivers/mmc/host/dw_mmc-pltfm.c
+++ b/drivers/mmc/host/dw_mmc-pltfm.c
@@ -78,7 +78,8 @@  static int dw_mci_pltfm_probe(struct platform_device *pdev)
 
 	if (pdev->dev.of_node) {
 		match = of_match_node(dw_mci_pltfm_match, pdev->dev.of_node);
-		drv_data = match->data;
+		if (match)
+			drv_data = match->data;
 	}
 
 	return dw_mci_pltfm_register(pdev, drv_data);
diff --git a/drivers/mmc/host/sdhci-of-arasan.c b/drivers/mmc/host/sdhci-of-arasan.c
index fb26e743e1fd..f2090f944a0e 100644
--- a/drivers/mmc/host/sdhci-of-arasan.c
+++ b/drivers/mmc/host/sdhci-of-arasan.c
@@ -1520,6 +1520,8 @@  static int sdhci_arasan_probe(struct platform_device *pdev)
 	const struct sdhci_arasan_of_data *data;
 
 	match = of_match_node(sdhci_arasan_of_match, pdev->dev.of_node);
+	if (match == NULL)
+		return -ENOPARAM;
 	data = match->data;
 	host = sdhci_pltfm_init(pdev, data->pdata, sizeof(*sdhci_arasan));