[v2] mmc: dw_mmc: Fix to avoid potential NULL pointer dereference
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Message ID 20190319014551.16559-1-pakki001@umn.edu
State New
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  • [v2] mmc: dw_mmc: Fix to avoid potential NULL pointer dereference
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Commit Message

Aditya Pakki March 19, 2019, 1:45 a.m. UTC
of_match_node can fail and return NULL in case no matching structure.
The patches checks for such a scenario and returns -ENXIO.

---
V1: Added files dw_mmc-zx.c and dw_mmc-rockchip.c

Signed-off-by: Aditya Pakki <pakki001@umn.edu>
---
 drivers/mmc/host/dw_mmc-exynos.c   | 2 ++
 drivers/mmc/host/dw_mmc-k3.c       | 2 ++
 drivers/mmc/host/dw_mmc-pltfm.c    | 2 ++
 drivers/mmc/host/dw_mmc-rockchip.c | 2 ++
 drivers/mmc/host/dw_mmc-zx.c       | 2 ++
 5 files changed, 10 insertions(+)

Comments

Robin Murphy March 19, 2019, 11:09 a.m. UTC | #1
On 19/03/2019 01:45, Aditya Pakki wrote:
> of_match_node can fail and return NULL in case no matching structure.
> The patches checks for such a scenario and returns -ENXIO.

FWIW, it looks like most of these instances could be cleaned up even 
more with of_device_get_match_data().

In general, do bear in mind that adding these NULL checks *everywhere* 
will in many cases just amount to useless dead code - a pure DT-based 
driver can usually freely assume of_match_node() returns non-NULL for 
its own device and match table in its probe routine, because that probe 
routine only ever gets called if of_driver_match_device() has already 
made the same match in the first place.

Robin.

> ---
> V1: Added files dw_mmc-zx.c and dw_mmc-rockchip.c
> 
> Signed-off-by: Aditya Pakki <pakki001@umn.edu>
> ---
>   drivers/mmc/host/dw_mmc-exynos.c   | 2 ++
>   drivers/mmc/host/dw_mmc-k3.c       | 2 ++
>   drivers/mmc/host/dw_mmc-pltfm.c    | 2 ++
>   drivers/mmc/host/dw_mmc-rockchip.c | 2 ++
>   drivers/mmc/host/dw_mmc-zx.c       | 2 ++
>   5 files changed, 10 insertions(+)
> 
> diff --git a/drivers/mmc/host/dw_mmc-exynos.c b/drivers/mmc/host/dw_mmc-exynos.c
> index d46c3439b508..8a75d7314606 100644
> --- a/drivers/mmc/host/dw_mmc-exynos.c
> +++ b/drivers/mmc/host/dw_mmc-exynos.c
> @@ -554,6 +554,8 @@ static int dw_mci_exynos_probe(struct platform_device *pdev)
>   	int ret;
>   
>   	match = of_match_node(dw_mci_exynos_match, pdev->dev.of_node);
> +	if (!match)
> +		return -ENXIO;
>   	drv_data = match->data;
>   
>   	pm_runtime_get_noresume(&pdev->dev);
> diff --git a/drivers/mmc/host/dw_mmc-k3.c b/drivers/mmc/host/dw_mmc-k3.c
> index 89cdb3d533bb..cc50b7546a20 100644
> --- a/drivers/mmc/host/dw_mmc-k3.c
> +++ b/drivers/mmc/host/dw_mmc-k3.c
> @@ -459,6 +459,8 @@ static int dw_mci_k3_probe(struct platform_device *pdev)
>   	const struct of_device_id *match;
>   
>   	match = of_match_node(dw_mci_k3_match, pdev->dev.of_node);
> +	if (!match)
> +		return -ENXIO;
>   	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 58c13e21bd5a..b1948989f617 100644
> --- a/drivers/mmc/host/dw_mmc-pltfm.c
> +++ b/drivers/mmc/host/dw_mmc-pltfm.c
> @@ -82,6 +82,8 @@ 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);
> +		if (!match)
> +			return -ENXIO;
>   		drv_data = match->data;
>   	}
>   
> diff --git a/drivers/mmc/host/dw_mmc-rockchip.c b/drivers/mmc/host/dw_mmc-rockchip.c
> index 8c86a800a8fd..20e3471260ea 100644
> --- a/drivers/mmc/host/dw_mmc-rockchip.c
> +++ b/drivers/mmc/host/dw_mmc-rockchip.c
> @@ -344,6 +344,8 @@ static int dw_mci_rockchip_probe(struct platform_device *pdev)
>   		return -ENODEV;
>   
>   	match = of_match_node(dw_mci_rockchip_match, pdev->dev.of_node);
> +	if (!match)
> +		return -ENXIO;
>   	drv_data = match->data;
>   
>   	pm_runtime_get_noresume(&pdev->dev);
> diff --git a/drivers/mmc/host/dw_mmc-zx.c b/drivers/mmc/host/dw_mmc-zx.c
> index c06b5393312f..abea35431045 100644
> --- a/drivers/mmc/host/dw_mmc-zx.c
> +++ b/drivers/mmc/host/dw_mmc-zx.c
> @@ -213,6 +213,8 @@ static int dw_mci_zx_probe(struct platform_device *pdev)
>   	const struct of_device_id *match;
>   
>   	match = of_match_node(dw_mci_zx_match, pdev->dev.of_node);
> +	if (!match)
> +		return -ENXIO;
>   	drv_data = match->data;
>   
>   	return dw_mci_pltfm_register(pdev, drv_data);
>

Patch
diff mbox series

diff --git a/drivers/mmc/host/dw_mmc-exynos.c b/drivers/mmc/host/dw_mmc-exynos.c
index d46c3439b508..8a75d7314606 100644
--- a/drivers/mmc/host/dw_mmc-exynos.c
+++ b/drivers/mmc/host/dw_mmc-exynos.c
@@ -554,6 +554,8 @@  static int dw_mci_exynos_probe(struct platform_device *pdev)
 	int ret;
 
 	match = of_match_node(dw_mci_exynos_match, pdev->dev.of_node);
+	if (!match)
+		return -ENXIO;
 	drv_data = match->data;
 
 	pm_runtime_get_noresume(&pdev->dev);
diff --git a/drivers/mmc/host/dw_mmc-k3.c b/drivers/mmc/host/dw_mmc-k3.c
index 89cdb3d533bb..cc50b7546a20 100644
--- a/drivers/mmc/host/dw_mmc-k3.c
+++ b/drivers/mmc/host/dw_mmc-k3.c
@@ -459,6 +459,8 @@  static int dw_mci_k3_probe(struct platform_device *pdev)
 	const struct of_device_id *match;
 
 	match = of_match_node(dw_mci_k3_match, pdev->dev.of_node);
+	if (!match)
+		return -ENXIO;
 	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 58c13e21bd5a..b1948989f617 100644
--- a/drivers/mmc/host/dw_mmc-pltfm.c
+++ b/drivers/mmc/host/dw_mmc-pltfm.c
@@ -82,6 +82,8 @@  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);
+		if (!match)
+			return -ENXIO;
 		drv_data = match->data;
 	}
 
diff --git a/drivers/mmc/host/dw_mmc-rockchip.c b/drivers/mmc/host/dw_mmc-rockchip.c
index 8c86a800a8fd..20e3471260ea 100644
--- a/drivers/mmc/host/dw_mmc-rockchip.c
+++ b/drivers/mmc/host/dw_mmc-rockchip.c
@@ -344,6 +344,8 @@  static int dw_mci_rockchip_probe(struct platform_device *pdev)
 		return -ENODEV;
 
 	match = of_match_node(dw_mci_rockchip_match, pdev->dev.of_node);
+	if (!match)
+		return -ENXIO;
 	drv_data = match->data;
 
 	pm_runtime_get_noresume(&pdev->dev);
diff --git a/drivers/mmc/host/dw_mmc-zx.c b/drivers/mmc/host/dw_mmc-zx.c
index c06b5393312f..abea35431045 100644
--- a/drivers/mmc/host/dw_mmc-zx.c
+++ b/drivers/mmc/host/dw_mmc-zx.c
@@ -213,6 +213,8 @@  static int dw_mci_zx_probe(struct platform_device *pdev)
 	const struct of_device_id *match;
 
 	match = of_match_node(dw_mci_zx_match, pdev->dev.of_node);
+	if (!match)
+		return -ENXIO;
 	drv_data = match->data;
 
 	return dw_mci_pltfm_register(pdev, drv_data);