airo: airo_get_encode{,ext} potential buffer overflow

Feeding the return code of get_wep_key directly to the length parameter
of memcpy is a bad idea since it could be -1...

Reported-by: Eugene Teo <eugeneteo@kernel.sg>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

1 files changed, 8 insertions, 2 deletions

diff --git a/drivers/net/wireless/airo.c b/drivers/net/wireless/airo.c
index c36d3a3d655f..d73475739127 100644
--- a/drivers/net/wireless/airo.c
+++ b/drivers/net/wireless/airo.c
@@ -6501,7 +6501,10 @@ static int airo_get_encode(struct net_device *dev,
 
         /* Copy the key to the user buffer */
         dwrq->length = get_wep_key(local, index, &buf[0], sizeof(buf));
-        memcpy(extra, buf, dwrq->length);
+        if (dwrq->length != -1)
+                memcpy(extra, buf, dwrq->length);
+        else
+                dwrq->length = 0;
 
         return 0;
 }
@@ -6659,7 +6662,10 @@ static int airo_get_encodeext(struct net_device *dev,
         
         /* Copy the key to the user buffer */
         ext->key_len = get_wep_key(local, idx, &buf[0], sizeof(buf));
-        memcpy(extra, buf, ext->key_len);
+        if (ext->key_len != -1)
+                memcpy(extra, buf, ext->key_len);
+        else
+                ext->key_len = 0;
 
         return 0;
 }