mmux: mmio: fix IS_ERR() vs NULL check for mux_mmio_probe()

[PATCH] mmux: mmio: fix IS_ERR() vs NULL check for mux_mmio_probe()

Posted by Alper Ak 1 month, 1 week ago

devm_kmalloc() returns NULL on failure, not an ERR_PTR value. The
current IS_ERR() check will never catch allocation failures, which
could lead to NULL pointer dereference.

Signed-off-by: Alper Ak <alperyasinak1@gmail.com>
---
 drivers/mux/mmio.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/drivers/mux/mmio.c b/drivers/mux/mmio.c
index e4ddb1e61923..3409af1ffb80 100644
--- a/drivers/mux/mmio.c
+++ b/drivers/mux/mmio.c
@@ -101,13 +101,13 @@ static int mux_mmio_probe(struct platform_device *pdev)
 	mux_mmio = mux_chip_priv(mux_chip);
 
 	mux_mmio->fields = devm_kmalloc(dev, num_fields * sizeof(*mux_mmio->fields), GFP_KERNEL);
-	if (IS_ERR(mux_mmio->fields))
-		return PTR_ERR(mux_mmio->fields);
+	if (!mux_mmio->fields)
+		return -ENOMEM;
 
 	mux_mmio->hardware_states = devm_kmalloc(dev, num_fields *
 						 sizeof(*mux_mmio->hardware_states), GFP_KERNEL);
-	if (IS_ERR(mux_mmio->hardware_states))
-		return PTR_ERR(mux_mmio->hardware_states);
+	if (!mux_mmio->hardware_states)
+		return -ENOMEM;
 
 	for (i = 0; i < num_fields; i++) {
 		struct mux_control *mux = &mux_chip->mux[i];
-- 
2.43.0

Re: [PATCH] mmux: mmio: fix IS_ERR() vs NULL check for mux_mmio_probe()

Posted by Krzysztof Kozlowski 1 month, 1 week ago

On 25/12/2025 12:41, Alper Ak wrote:
> devm_kmalloc() returns NULL on failure, not an ERR_PTR value. The
> current IS_ERR() check will never catch allocation failures, which
> could lead to NULL pointer dereference.
> 
> Signed-off-by: Alper Ak <alperyasinak1@gmail.com>

Missing fixes tag.

> ---
>  drivers/mux/mmio.c | 8 ++++----
>  1 file changed, 4 insertions(+), 4 deletions(-)
> 
> diff --git a/drivers/mux/mmio.c b/drivers/mux/mmio.c
> index e4ddb1e61923..3409af1ffb80 100644
> --- a/drivers/mux/mmio.c
> +++ b/drivers/mux/mmio.c
> @@ -101,13 +101,13 @@ static int mux_mmio_probe(struct platform_device *pdev)
>  	mux_mmio = mux_chip_priv(mux_chip);
>  
>  	mux_mmio->fields = devm_kmalloc(dev, num_fields * sizeof(*mux_mmio->fields), GFP_KERNEL);
> -	if (IS_ERR(mux_mmio->fields))
> -		return PTR_ERR(mux_mmio->fields);

I really wonder from where do the people sometimes copy code...

With missing tag:

Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@oss.qualcomm.com>

Best regards,
Krzysztof

[PATCH v2] mux: mmio: fix IS_ERR() vs NULL check for mux_mmio_probe()

Posted by Alper Ak 1 month, 1 week ago

devm_kmalloc() returns NULL on failure, not an ERR_PTR value. The
current IS_ERR() check will never catch allocation failures, which
could lead to NULL pointer dereference.

Fixes: 4863cb2b0f50 ("mux: mmio: Add suspend and resume support")
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@oss.qualcomm.com>
Signed-off-by: Alper Ak <alperyasinak1@gmail.com>
---
 drivers/mux/mmio.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/drivers/mux/mmio.c b/drivers/mux/mmio.c
index e4ddb1e61923..3409af1ffb80 100644
--- a/drivers/mux/mmio.c
+++ b/drivers/mux/mmio.c
@@ -101,13 +101,13 @@ static int mux_mmio_probe(struct platform_device *pdev)
 	mux_mmio = mux_chip_priv(mux_chip);
 
 	mux_mmio->fields = devm_kmalloc(dev, num_fields * sizeof(*mux_mmio->fields), GFP_KERNEL);
-	if (IS_ERR(mux_mmio->fields))
-		return PTR_ERR(mux_mmio->fields);
+	if (!mux_mmio->fields)
+		return -ENOMEM;
 
 	mux_mmio->hardware_states = devm_kmalloc(dev, num_fields *
 						 sizeof(*mux_mmio->hardware_states), GFP_KERNEL);
-	if (IS_ERR(mux_mmio->hardware_states))
-		return PTR_ERR(mux_mmio->hardware_states);
+	if (!mux_mmio->hardware_states)
+		return -ENOMEM;
 
 	for (i = 0; i < num_fields; i++) {
 		struct mux_control *mux = &mux_chip->mux[i];
-- 
2.43.0