[PPPOL2TP]: Fix use-after-free
Don't use skb->len after passing it to ip_queue_xmit.
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/pppol2tp.c b/drivers/net/pppol2tp.c
index 5891a0f..856610f 100644
--- a/drivers/net/pppol2tp.c
+++ b/drivers/net/pppol2tp.c
@@ -824,6 +824,7 @@
struct pppol2tp_session *session;
struct pppol2tp_tunnel *tunnel;
struct udphdr *uh;
+ unsigned int len;
error = -ENOTCONN;
if (sock_flag(sk, SOCK_DEAD) || !(sk->sk_state & PPPOX_CONNECTED))
@@ -912,14 +913,15 @@
}
/* Queue the packet to IP for output */
+ len = skb->len;
error = ip_queue_xmit(skb, 1);
/* Update stats */
if (error >= 0) {
tunnel->stats.tx_packets++;
- tunnel->stats.tx_bytes += skb->len;
+ tunnel->stats.tx_bytes += len;
session->stats.tx_packets++;
- session->stats.tx_bytes += skb->len;
+ session->stats.tx_bytes += len;
} else {
tunnel->stats.tx_errors++;
session->stats.tx_errors++;
@@ -958,6 +960,7 @@
__wsum csum = 0;
struct sk_buff *skb2 = NULL;
struct udphdr *uh;
+ unsigned int len;
if (sock_flag(sk, SOCK_DEAD) || !(sk->sk_state & PPPOX_CONNECTED))
goto abort;
@@ -1050,14 +1053,15 @@
skb2->dst = sk_dst_get(sk_tun);
/* Queue the packet to IP for output */
+ len = skb2->len;
rc = ip_queue_xmit(skb2, 1);
/* Update stats */
if (rc >= 0) {
tunnel->stats.tx_packets++;
- tunnel->stats.tx_bytes += skb2->len;
+ tunnel->stats.tx_bytes += len;
session->stats.tx_packets++;
- session->stats.tx_bytes += skb2->len;
+ session->stats.tx_bytes += len;
} else {
tunnel->stats.tx_errors++;
session->stats.tx_errors++;