From: Ralf Baechle <ralf@linux-mips.org>
Date: Tue, 4 Jul 2006 02:29:15 +0000 (-0700)
Subject: [ROSE]: Fix dereference of skb pointer after free.
X-Git-Tag: v2.6.18-rc1~21^2~22
X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=8dc22d2b642f8a6f14ef8878777a05311e5d1d7e;p=linux-2.6

[ROSE]: Fix dereference of skb pointer after free.

If rose_route_frame return success we'll dereference a stale pointer.
Likely this is only going to result in bad statistics for the ROSE
interface.

This fixes coverity 946.

Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
---

diff --git a/net/rose/rose_dev.c b/net/rose/rose_dev.c
index 9d0bf2a1ea..7c279e2659 100644
--- a/net/rose/rose_dev.c
+++ b/net/rose/rose_dev.c
@@ -59,6 +59,7 @@ static int rose_rebuild_header(struct sk_buff *skb)
 	struct net_device_stats *stats = netdev_priv(dev);
 	unsigned char *bp = (unsigned char *)skb->data;
 	struct sk_buff *skbn;
+	unsigned int len;
 
 #ifdef CONFIG_INET
 	if (arp_find(bp + 7, skb)) {
@@ -75,6 +76,8 @@ static int rose_rebuild_header(struct sk_buff *skb)
 
 	kfree_skb(skb);
 
+	len = skbn->len;
+
 	if (!rose_route_frame(skbn, NULL)) {
 		kfree_skb(skbn);
 		stats->tx_errors++;
@@ -82,7 +85,7 @@ static int rose_rebuild_header(struct sk_buff *skb)
 	}
 
 	stats->tx_packets++;
-	stats->tx_bytes += skbn->len;
+	stats->tx_bytes += len;
 #endif
 	return 1;
 }