[PATCH] Staging: rtl8192e prohibit deferencing of NULL pointer

[PATCH] Staging: rtl8192e prohibit deferencing of NULL pointer

[Andreas Platschek]

If ieee = NULL we jump to rx_dropped. Therefore we have to check again,
if ieee != NULL before we use it.

Signed-off-by: Andreas Platschek <platschek@ict.tuwien.ac.at>
---
 drivers/staging/rtl8192e/rtllib_rx.c |    4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/staging/rtl8192e/rtllib_rx.c
b/drivers/staging/rtl8192e/rtllib_rx.c
index 60de54c..badf6e2 100644
--- a/drivers/staging/rtl8192e/rtllib_rx.c
+++ b/drivers/staging/rtl8192e/rtllib_rx.c
@@ -1496,7 +1496,9 @@ int rtllib_rx(struct rtllib_device *ieee, struct
sk_buff *skb,
     return ret;
 
  rx_dropped:
-    ieee->stats.rx_dropped++;
+    if (ieee != NULL) {
+        ieee->stats.rx_dropped++;
+    }
     return 0;
 }
 EXPORT_SYMBOL(rtllib_rx);
-- 
1.7.10.4

Re: [PATCH] Staging: rtl8192e prohibit deferencing of NULL pointer

[Valentina Manea]

On Wed, Jun 18, 2014 at 11:16 AM, Andreas Platschek
<platschek@ict.tuwien.ac.at> wrote:
>
>   rx_dropped:
> -    ieee->stats.rx_dropped++;
> +    if (ieee != NULL) {
> +        ieee->stats.rx_dropped++;
> +    }
>      return 0;

Style nit: don't use braces around a single statement.

Tina

Re: [PATCH] Staging: rtl8192e prohibit deferencing of NULL pointer

[Dan Carpenter]

On Wed, Jun 18, 2014 at 06:16:09PM +0000, Andreas Platschek wrote:
> If ieee = NULL we jump to rx_dropped. Therefore we have to check again,
> if ieee != NULL before we use it.

Take a look at the caller as well.  It doesn't check ieee for NULL so
probably this can never be NULL.  How would that make sense if ieee were
NULL?

Also the patch doesn't apply.  Read Documentation/email-clients.txt

regards,
dan carpenter