Re: [PATCHv2] net: wireless: wcn36xx: fix potential NULL pointer dereference

[Eugene Krasnikov]

> +               if (msg_ind)
> +                       break;
> +               /* FIXME: Do something smarter then just printing an error. */
> +               wcn36xx_err("Run out of memory while handling SMD_EVENT (%d)\n",

I think code will look neater if error case will be handled in "else"
statement something like:
if (msg_ind) {
...
} else {
/*print message*/
}
/*unlock and break;*/

How about that?


On Mon, Dec 2, 2013 at 1:09 PM, Michal Nazarewicz <mina86@xxxxxxxxxx> wrote:
>
> If kmalloc fails wcn36xx_smd_rsp_process will attempt to dereference
> a NULL pointer.  There might be a better error recovery then just
> printing an error, but printing an error message is better then the
> current behaviour.
>
> Signed-off-by: Michal Nazarewicz <mina86@xxxxxxxxxx>
> ---
>  drivers/net/wireless/ath/wcn36xx/smd.c | 19 +++++++++++++------
>  1 file changed, 13 insertions(+), 6 deletions(-)
>
> On Sun, Dec 01 2013, Peter Stuge wrote:
>> Michal Nazarewicz wrote:
>>> +                    wcn36xx_err("Run out of memory while hnadling SMD_EVENT (%d)\n",
>>> +                                msg_header->msg_type);
>>
>> Typo hnadling.
>
> Fixed.
>
> diff --git a/drivers/net/wireless/ath/wcn36xx/smd.c b/drivers/net/wireless/ath/wcn36xx/smd.c
> index de9eb2c..3663394 100644
> --- a/drivers/net/wireless/ath/wcn36xx/smd.c
> +++ b/drivers/net/wireless/ath/wcn36xx/smd.c
> @@ -2041,13 +2041,20 @@ static void wcn36xx_smd_rsp_process(struct wcn36xx *wcn, void *buf, size_t len)
>         case WCN36XX_HAL_DELETE_STA_CONTEXT_IND:
>                 mutex_lock(&wcn->hal_ind_mutex);
>                 msg_ind = kmalloc(sizeof(*msg_ind), GFP_KERNEL);
> -               msg_ind->msg_len = len;
> -               msg_ind->msg = kmalloc(len, GFP_KERNEL);
> -               memcpy(msg_ind->msg, buf, len);
> -               list_add_tail(&msg_ind->list, &wcn->hal_ind_queue);
> -               queue_work(wcn->hal_ind_wq, &wcn->hal_ind_work);
> -               wcn36xx_dbg(WCN36XX_DBG_HAL, "indication arrived\n");
> +               if (msg_ind) {
> +                       msg_ind->msg_len = len;
> +                       msg_ind->msg = kmalloc(len, GFP_KERNEL);
> +                       memcpy(msg_ind->msg, buf, len);
> +                       list_add_tail(&msg_ind->list, &wcn->hal_ind_queue);
> +                       queue_work(wcn->hal_ind_wq, &wcn->hal_ind_work);
> +                       wcn36xx_dbg(WCN36XX_DBG_HAL, "indication arrived\n");
> +               }
>                 mutex_unlock(&wcn->hal_ind_mutex);
> +               if (msg_ind)
> +                       break;
> +               /* FIXME: Do something smarter then just printing an error. */
> +               wcn36xx_err("Run out of memory while handling SMD_EVENT (%d)\n",
> +                           msg_header->msg_type);
>                 break;
>         default:
>                 wcn36xx_err("SMD_EVENT (%d) not supported\n",
> --
> 1.8.4.1
>
> --
> Best regards,                                         _     _
> .o. | Liege of Serenely Enlightened Majesty of      o' \,=./ `o
> ..o | Computer Science,  MichaÅ âmina86â Nazarewicz    (o o)
> ooo +--<mpn@xxxxxxxxxx>--<xmpp:mina86@xxxxxxxxxx>--ooO--(_)--Ooo--



-- 
Best regards,
Eugene
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/