[PATCH] staging: wfx: correct error handling code in wfx_init_common()

[PATCH] staging: wfx: correct error handling code in wfx_init_common()

[Jia-Ju Bai]

In wfx_init_common(), devm_kmalloc() can fail, so its return value
should be checked. Moreover, in error handling code, ieee80211_free_hw()
should be called to free the memory allocated by ieee80211_alloc_hw().

Fixes: 40115bbc40e2 ("staging: wfx: implement the rest of mac80211 API")
Reported-by: TOTE Robot <oslab@tsinghua.edu.cn>
Signed-off-by: Jia-Ju Bai <baijiaju1990@gmail.com>
---
 drivers/staging/wfx/main.c | 12 ++++++++++--
 1 file changed, 10 insertions(+), 2 deletions(-)

diff --git a/drivers/staging/wfx/main.c b/drivers/staging/wfx/main.c
index 858d778cc589..ebc6c7db8d63 100644
--- a/drivers/staging/wfx/main.c
+++ b/drivers/staging/wfx/main.c
@@ -307,6 +307,10 @@ 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]) {
+		ieee80211_free_hw(hw);
+		return NULL;
+	}
 	/* FIXME: also copy wfx_rates and wfx_2ghz_chantable */
 	memcpy(hw->wiphy->bands[NL80211_BAND_2GHZ], &wfx_band_2ghz,
 	       sizeof(wfx_band_2ghz));
@@ -321,8 +325,10 @@ struct wfx_dev *wfx_init_common(struct device *dev,
 				&wdev->pdata.file_pds);
 	wdev->pdata.gpio_wakeup = devm_gpiod_get_optional(dev, "wakeup",
 							  GPIOD_OUT_LOW);
-	if (IS_ERR(wdev->pdata.gpio_wakeup))
+	if (IS_ERR(wdev->pdata.gpio_wakeup)) {
+		ieee80211_free_hw(hw);
 		return NULL;
+	}
 	if (wdev->pdata.gpio_wakeup)
 		gpiod_set_consumer_name(wdev->pdata.gpio_wakeup, "wfx wakeup");
 
@@ -337,8 +343,10 @@ struct wfx_dev *wfx_init_common(struct device *dev,
 	wfx_init_hif_cmd(&wdev->hif_cmd);
 	wdev->force_ps_timeout = -1;
 
-	if (devm_add_action_or_reset(dev, wfx_free_common, wdev))
+	if (devm_add_action_or_reset(dev, wfx_free_common, wdev)) {
+		ieee80211_free_hw(hw);
 		return NULL;
+	}
 
 	return wdev;
 }
-- 
2.17.1

Re: [PATCH] staging: wfx: correct error handling code in wfx_init_common()

[Dan Carpenter]

Thanks, but someone already fixed part of this in linux-next and I think
they sent the patch for the rest, but it just hasn't been applied yet.

> @@ -337,8 +343,10 @@ struct wfx_dev *wfx_init_common(struct device *dev,
>  	wfx_init_hif_cmd(&wdev->hif_cmd);
>  	wdev->force_ps_timeout = -1;
>  
> -	if (devm_add_action_or_reset(dev, wfx_free_common, wdev))
> +	if (devm_add_action_or_reset(dev, wfx_free_common, wdev)) {
> +		ieee80211_free_hw(hw);

This introduces a double free.  The devm_add_action_or_reset() will call
wfx_free_common() on failure.

>  		return NULL;
> +	}
>  
>  	return wdev;

regards,
dan carpenter