[PATCH v2 1/2] staging: wfx: fix an error handling in wfx_init_common()

[PATCH v2 1/2] staging: wfx: fix an error handling in wfx_init_common()

[xkernel.wang]

From: Xiaoke Wang <xkernel.wang@foxmail.com>

One error handler of wfx_init_common() return without calling
ieee80211_free_hw(hw), which may result in memory leak. And I add
one err label to unify the error handler, which is useful for the
subsequent changes.

Suggested-by: Jérôme Pouiller <jerome.pouiller@silabs.com>
Signed-off-by: Xiaoke Wang <xkernel.wang@foxmail.com>
---
Changelog
v1->v2 restore the wrong modification of a return statement.
 drivers/staging/wfx/main.c | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/drivers/staging/wfx/main.c b/drivers/staging/wfx/main.c
index 4b9fdf9..9ff69c5 100644
--- a/drivers/staging/wfx/main.c
+++ b/drivers/staging/wfx/main.c
@@ -309,7 +309,8 @@ struct wfx_dev *wfx_init_common(struct device *dev,
 	wdev->pdata.gpio_wakeup = devm_gpiod_get_optional(dev, "wakeup",
 							  GPIOD_OUT_LOW);
 	if (IS_ERR(wdev->pdata.gpio_wakeup))
-		return NULL;
+		goto err;
+
 	if (wdev->pdata.gpio_wakeup)
 		gpiod_set_consumer_name(wdev->pdata.gpio_wakeup, "wfx wakeup");
 
@@ -328,6 +329,10 @@ struct wfx_dev *wfx_init_common(struct device *dev,
 		return NULL;
 
 	return wdev;
+
+err:
+	ieee80211_free_hw(hw);
+	return NULL;
 }
 
 int wfx_probe(struct wfx_dev *wdev)
-- 

[PATCH v2 2/2] staging: wfx: check the return value of devm_kmalloc()

[xkernel.wang]

From: Xiaoke Wang <xkernel.wang@foxmail.com>

devm_kmalloc() returns a pointer to allocated memory on success, NULL
on failure. While there is a memory allocation of devm_kmalloc()
without proper check. It is better to check the return value of it to
prevent wrong memory access.
And I use the err label which is introduced by the previous patch to
handle the error.

Signed-off-by: Xiaoke Wang <xkernel.wang@foxmail.com>
---
Changelog
v1->v2 update the description.
 drivers/staging/wfx/main.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/staging/wfx/main.c b/drivers/staging/wfx/main.c
index 9ff69c5..85fcdc3 100644
--- a/drivers/staging/wfx/main.c
+++ b/drivers/staging/wfx/main.c
@@ -294,6 +294,9 @@ struct wfx_dev *wfx_init_common(struct device *dev,
 	hw->wiphy->n_iface_combinations = ARRAY_SIZE(wfx_iface_combinations);
 	hw->wiphy->iface_combinations = wfx_iface_combinations;
 	hw->wiphy->bands[NL80211_BAND_2GHZ] = devm_kmalloc(dev, sizeof(wfx_band_2ghz), GFP_KERNEL);
+	if (!hw->wiphy->bands[NL80211_BAND_2GHZ])
+		goto err;
+
 	// FIXME: also copy wfx_rates and wfx_2ghz_chantable
 	memcpy(hw->wiphy->bands[NL80211_BAND_2GHZ], &wfx_band_2ghz,
 	       sizeof(wfx_band_2ghz));
-- 

Re: [PATCH v2 1/2] staging: wfx: fix an error handling in wfx_init_common()

[Jérôme Pouiller]

On Friday 18 February 2022 14:59:45 CET xkernel.wang@foxmail.com wrote:
> From: Xiaoke Wang <xkernel.wang@foxmail.com>
> 
> One error handler of wfx_init_common() return without calling
> ieee80211_free_hw(hw), which may result in memory leak. And I add
> one err label to unify the error handler, which is useful for the
> subsequent changes.
> 
> Suggested-by: Jérôme Pouiller <jerome.pouiller@silabs.com>
> Signed-off-by: Xiaoke Wang <xkernel.wang@foxmail.com>
> ---
> Changelog
> v1->v2 restore the wrong modification of a return statement.
>  drivers/staging/wfx/main.c | 7 ++++++-
>  1 file changed, 6 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/staging/wfx/main.c b/drivers/staging/wfx/main.c
> index 4b9fdf9..9ff69c5 100644
> --- a/drivers/staging/wfx/main.c
> +++ b/drivers/staging/wfx/main.c
> @@ -309,7 +309,8 @@ struct wfx_dev *wfx_init_common(struct device *dev,
>         wdev->pdata.gpio_wakeup = devm_gpiod_get_optional(dev, "wakeup",
>                                                           GPIOD_OUT_LOW);
>         if (IS_ERR(wdev->pdata.gpio_wakeup))
> -               return NULL;
> +               goto err;
> +
>         if (wdev->pdata.gpio_wakeup)
>                 gpiod_set_consumer_name(wdev->pdata.gpio_wakeup, "wfx wakeup");
> 
> @@ -328,6 +329,10 @@ struct wfx_dev *wfx_init_common(struct device *dev,
>                 return NULL;
> 
>         return wdev;
> +
> +err:
> +       ieee80211_free_hw(hw);
> +       return NULL;
>  }
> 
>  int wfx_probe(struct wfx_dev *wdev)
> --
> 

Looks right.

Reviewed-by: Jérôme Pouiller <jerome.pouiller@silabs.com>



-- 
Jérôme Pouiller

Re: [PATCH v2 2/2] staging: wfx: check the return value of devm_kmalloc()

[Jérôme Pouiller]

On Friday 18 February 2022 15:04:02 CET xkernel.wang@foxmail.com wrote:
> 
> From: Xiaoke Wang <xkernel.wang@foxmail.com>
> 
> devm_kmalloc() returns a pointer to allocated memory on success, NULL
> on failure. While there is a memory allocation of devm_kmalloc()
> without proper check. It is better to check the return value of it to
> prevent wrong memory access.
> And I use the err label which is introduced by the previous patch to
> handle the error.
This last sentence is not very useful, but it is not a big deal.

Reviewed-by: Jérôme Pouiller <jerome.pouiller@silabs.com>


> 
> Signed-off-by: Xiaoke Wang <xkernel.wang@foxmail.com>
> ---
> Changelog
> v1->v2 update the description.
>  drivers/staging/wfx/main.c | 3 +++
>  1 file changed, 3 insertions(+)
> 
> diff --git a/drivers/staging/wfx/main.c b/drivers/staging/wfx/main.c
> index 9ff69c5..85fcdc3 100644
> --- a/drivers/staging/wfx/main.c
> +++ b/drivers/staging/wfx/main.c
> @@ -294,6 +294,9 @@ struct wfx_dev *wfx_init_common(struct device *dev,
>         hw->wiphy->n_iface_combinations = ARRAY_SIZE(wfx_iface_combinations);
>         hw->wiphy->iface_combinations = wfx_iface_combinations;
>         hw->wiphy->bands[NL80211_BAND_2GHZ] = devm_kmalloc(dev, sizeof(wfx_band_2ghz), GFP_KERNEL);
> +       if (!hw->wiphy->bands[NL80211_BAND_2GHZ])
> +               goto err;
> +
>         // FIXME: also copy wfx_rates and wfx_2ghz_chantable
>         memcpy(hw->wiphy->bands[NL80211_BAND_2GHZ], &wfx_band_2ghz,
>                sizeof(wfx_band_2ghz));
> --
> 

-- 
Jérôme Pouiller

Re: [PATCH v2 1/2] staging: wfx: fix an error handling in wfx_init_common()

[Dan Carpenter]

Looks good, thanks.

Reviewed-by: Dan Carpenter <dan.carpenter@oracle.com>

regards,
dan carpenter

Re: [PATCH v2 2/2] staging: wfx: check the return value of devm_kmalloc()

[Greg KH]

On Fri, Feb 18, 2022 at 10:04:02PM +0800, xkernel.wang@foxmail.com wrote:
> From: Xiaoke Wang <xkernel.wang@foxmail.com>
> 
> devm_kmalloc() returns a pointer to allocated memory on success, NULL
> on failure. While there is a memory allocation of devm_kmalloc()
> without proper check. It is better to check the return value of it to
> prevent wrong memory access.
> And I use the err label which is introduced by the previous patch to
> handle the error.
> 
> Signed-off-by: Xiaoke Wang <xkernel.wang@foxmail.com>
> ---
> Changelog
> v1->v2 update the description.
>  drivers/staging/wfx/main.c | 3 +++
>  1 file changed, 3 insertions(+)
> 
> diff --git a/drivers/staging/wfx/main.c b/drivers/staging/wfx/main.c
> index 9ff69c5..85fcdc3 100644
> --- a/drivers/staging/wfx/main.c
> +++ b/drivers/staging/wfx/main.c
> @@ -294,6 +294,9 @@ struct wfx_dev *wfx_init_common(struct device *dev,
>  	hw->wiphy->n_iface_combinations = ARRAY_SIZE(wfx_iface_combinations);
>  	hw->wiphy->iface_combinations = wfx_iface_combinations;
>  	hw->wiphy->bands[NL80211_BAND_2GHZ] = devm_kmalloc(dev, sizeof(wfx_band_2ghz), GFP_KERNEL);
> +	if (!hw->wiphy->bands[NL80211_BAND_2GHZ])
> +		goto err;
> +
>  	// FIXME: also copy wfx_rates and wfx_2ghz_chantable
>  	memcpy(hw->wiphy->bands[NL80211_BAND_2GHZ], &wfx_band_2ghz,
>  	       sizeof(wfx_band_2ghz));
> -- 

This patch does not apply to my tree at all.  Please rebase and resend.

thanks,

greg k-h