diff mbox

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

Message ID xa1tiov78kmp.fsf@mina86.com (mailing list archive)
State Not Applicable, archived
Headers show

Commit Message

Michał Nazarewicz Dec. 2, 2013, 1:09 p.m. UTC 
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@mina86.com>
---
 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.

Comments

Eugene Krasnikov Dec. 5, 2013, 8:41 a.m. UTC | #1 
> +               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@mina86.com> 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@mina86.com>
> ---
>  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,  Micha? “mina86” Nazarewicz    (o o)
> ooo +--<mpn@google.com>--<xmpp:mina86@jabber.org>--ooO--(_)--Ooo--
John W. Linville Dec. 6, 2013, 4:12 p.m. UTC | #2 
FWIW, I merged the earlier version.  Please send any changes as a
follow-up patch, probably against wireless-next.

John

On Thu, Dec 05, 2013 at 08:41:29AM +0000, Eugene Krasnikov wrote:
> > +               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@mina86.com> 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@mina86.com>
> > ---
> >  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,  Micha? “mina86” Nazarewicz    (o o)
> > ooo +--<mpn@google.com>--<xmpp:mina86@jabber.org>--ooO--(_)--Ooo--
> 
> 
> 
> -- 
> Best regards,
> Eugene
>
diff mbox

Patch

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",