[PATCH] orinoco: Information leakage due to incorrect padding

The orinoco driver can send uninitialized data exposing random pieces of
the system memory.  This happens because data is not padded with zeroes
when its length needs to be increased.

Reported by Meder Kydyraliev <meder@o0o.nu>
Signed-off-by: Pavel Roskin <proski@gnu.org>
Signed-off-by: Jeff Garzik <jgarzik@pobox.com>

drivers/net/wireless/orinoco.c

@@ -503,9 +503,14 @@ static int orinoco_xmit(struct sk_buff *skb, struct net_device *dev)
 		return 0;
 	}
 
-	/* Length of the packet body */
-	/* FIXME: what if the skb is smaller than this? */
-	len = max_t(int,skb->len - ETH_HLEN, ETH_ZLEN - ETH_HLEN);
+	/* Check packet length, pad short packets, round up odd length */
+	len = max_t(int, ALIGN(skb->len, 2), ETH_ZLEN);
+	if (skb->len < len) {
+		skb = skb_padto(skb, len);
+		if (skb == NULL)
+			goto fail;
+	}
+	len -= ETH_HLEN;
 
 	eh = (struct ethhdr *)skb->data;
 
@@ -557,8 +562,7 @@ static int orinoco_xmit(struct sk_buff *skb, struct net_device *dev)
 		p = skb->data;
 	}
 
-	/* Round up for odd length packets */
-	err = hermes_bap_pwrite(hw, USER_BAP, p, ALIGN(data_len, 2),
+	err = hermes_bap_pwrite(hw, USER_BAP, p, data_len,
 				txfid, data_off);
 	if (err) {
 		printk(KERN_ERR "%s: Error %d writing packet to BAP\n",