[PATCH][next] wil6210: fix potential null dereference of ndev before null check

[PATCH][next] wil6210: fix potential null dereference of ndev before null check

[Colin King]

From: Colin Ian King <colin.king@canonical.com>

The pointer ndev is being dereferenced before it is being null checked,
hence there is a potential null pointer deference. Fix this by only
dereferencing ndev after it has been null checked

Detected by CoverityScan, CID#1467010 ("Dereference before null check")

Fixes: e00243fab84b ("wil6210: infrastructure for multiple virtual interfaces")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
---
 drivers/net/wireless/ath/wil6210/main.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/net/wireless/ath/wil6210/main.c b/drivers/net/wireless/ath/wil6210/main.c
index a4b413e8d55a..82aec6b06d09 100644
--- a/drivers/net/wireless/ath/wil6210/main.c
+++ b/drivers/net/wireless/ath/wil6210/main.c
@@ -391,7 +391,7 @@ static void wil_fw_error_worker(struct work_struct *work)
 	struct wil6210_priv *wil = container_of(work, struct wil6210_priv,
 						fw_error_worker);
 	struct net_device *ndev = wil->main_ndev;
-	struct wireless_dev *wdev = ndev->ieee80211_ptr;
+	struct wireless_dev *wdev;
 
 	wil_dbg_misc(wil, "fw error worker\n");
 
@@ -399,6 +399,7 @@ static void wil_fw_error_worker(struct work_struct *work)
 		wil_info(wil, "No recovery - interface is down\n");
 		return;
 	}
+	wdev = ndev->ieee80211_ptr;
 
 	/* increment @recovery_count if less then WIL6210_FW_RECOVERY_TO
 	 * passed since last recovery attempt
-- 
2.15.1

Re: [PATCH][next] wil6210: fix potential null dereference of ndev before null check

[merez]

On 2018-03-28 20:40, Colin King wrote:
> From: Colin Ian King <colin.king@canonical.com>
> 
> The pointer ndev is being dereferenced before it is being null checked,
> hence there is a potential null pointer deference. Fix this by only
> dereferencing ndev after it has been null checked
> 
> Detected by CoverityScan, CID#1467010 ("Dereference before null check")
> 
> Fixes: e00243fab84b ("wil6210: infrastructure for multiple virtual 
> interfaces")
> Signed-off-by: Colin Ian King <colin.king@canonical.com>
> ---
>  drivers/net/wireless/ath/wil6210/main.c | 3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/net/wireless/ath/wil6210/main.c
> b/drivers/net/wireless/ath/wil6210/main.c
> index a4b413e8d55a..82aec6b06d09 100644
> --- a/drivers/net/wireless/ath/wil6210/main.c
> +++ b/drivers/net/wireless/ath/wil6210/main.c
> @@ -391,7 +391,7 @@ static void wil_fw_error_worker(struct work_struct 
> *work)
>  	struct wil6210_priv *wil = container_of(work, struct wil6210_priv,
>  						fw_error_worker);
>  	struct net_device *ndev = wil->main_ndev;
> -	struct wireless_dev *wdev = ndev->ieee80211_ptr;
> +	struct wireless_dev *wdev;
> 
>  	wil_dbg_misc(wil, "fw error worker\n");
> 
> @@ -399,6 +399,7 @@ static void wil_fw_error_worker(struct work_struct 
> *work)
>  		wil_info(wil, "No recovery - interface is down\n");
>  		return;
>  	}
> +	wdev = ndev->ieee80211_ptr;
> 
>  	/* increment @recovery_count if less then WIL6210_FW_RECOVERY_TO
>  	 * passed since last recovery attempt

Reviewed-by: Maya Erez <merez@codeaurora.org>

-- 
Maya Erez
Qualcomm Israel, Inc. on behalf of Qualcomm Innovation Center, Inc.
The Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, a 
Linux Foundation Collaborative Project

Re: [PATCH][next] wil6210: fix potential null dereference of ndev before null check

[Kalle Valo]

merez@codeaurora.org writes:

> On 2018-03-28 20:40, Colin King wrote:
>> From: Colin Ian King <colin.king@canonical.com>
>>
>> The pointer ndev is being dereferenced before it is being null checked,
>> hence there is a potential null pointer deference. Fix this by only
>> dereferencing ndev after it has been null checked
>>
>> Detected by CoverityScan, CID#1467010 ("Dereference before null check")
>>
>> Fixes: e00243fab84b ("wil6210: infrastructure for multiple virtual
>> interfaces")
>> Signed-off-by: Colin Ian King <colin.king@canonical.com>

[...]

> Reviewed-by: Maya Erez <merez@codeaurora.org>

Maya, as you are the wil6210 maintainer you can actually use Acked-by
instead of Reviewed-by. Not that it really matters which one you use,
both of them indicate me that you have checked and agree the patch, but
wanted to point out this anyway :)

-- 
Kalle Valo

Re: [next] wil6210: fix potential null dereference of ndev before null check

[Kalle Valo]

Colin Ian King <colin.king@canonical.com> wrote:

> The pointer ndev is being dereferenced before it is being null checked,
> hence there is a potential null pointer deference. Fix this by only
> dereferencing ndev after it has been null checked
> 
> Detected by CoverityScan, CID#1467010 ("Dereference before null check")
> 
> Fixes: e00243fab84b ("wil6210: infrastructure for multiple virtual interfaces")
> Signed-off-by: Colin Ian King <colin.king@canonical.com>
> Reviewed-by: Maya Erez <merez@codeaurora.org>
> Signed-off-by: Kalle Valo <kvalo@codeaurora.org>

Patch applied to ath-next branch of ath.git, thanks.

db5a4d5e1073 wil6210: fix potential null dereference of ndev before null check

-- 
https://patchwork.kernel.org/patch/10313705/

https://wireless.wiki.kernel.org/en/developers/documentation/submittingpatches