diff options
Diffstat (limited to 'drivers/net')
| -rw-r--r-- | drivers/net/pppol2tp.c | 25 |
1 files changed, 18 insertions, 7 deletions
diff --git a/drivers/net/pppol2tp.c b/drivers/net/pppol2tp.c index f8904fd9236..a7556cd2df7 100644 --- a/drivers/net/pppol2tp.c +++ b/drivers/net/pppol2tp.c @@ -488,7 +488,7 @@ static int pppol2tp_recv_core(struct sock *sock, struct sk_buff *skb) { struct pppol2tp_session *session = NULL; struct pppol2tp_tunnel *tunnel; - unsigned char *ptr; + unsigned char *ptr, *optr; u16 hdrflags; u16 tunnel_id, session_id; int length; @@ -496,7 +496,7 @@ static int pppol2tp_recv_core(struct sock *sock, struct sk_buff *skb) tunnel = pppol2tp_sock_to_tunnel(sock); if (tunnel == NULL) - goto error; + goto no_tunnel; /* UDP always verifies the packet length. */ __skb_pull(skb, sizeof(struct udphdr)); @@ -509,7 +509,7 @@ static int pppol2tp_recv_core(struct sock *sock, struct sk_buff *skb) } /* Point to L2TP header */ - ptr = skb->data; + optr = ptr = skb->data; /* Get L2TP header flags */ hdrflags = ntohs(*(__be16*)ptr); @@ -637,12 +637,14 @@ static int pppol2tp_recv_core(struct sock *sock, struct sk_buff *skb) /* If offset bit set, skip it. */ if (hdrflags & L2TP_HDRFLAG_O) { offset = ntohs(*(__be16 *)ptr); - skb->transport_header += 2 + offset; - if (!pskb_may_pull(skb, skb_transport_offset(skb) + 2)) - goto discard; + ptr += 2 + offset; } - __skb_pull(skb, skb_transport_offset(skb)); + offset = ptr - optr; + if (!pskb_may_pull(skb, offset)) + goto discard; + + __skb_pull(skb, offset); /* Skip PPP header, if present. In testing, Microsoft L2TP clients * don't send the PPP header (PPP header compression enabled), but @@ -652,6 +654,9 @@ static int pppol2tp_recv_core(struct sock *sock, struct sk_buff *skb) * Note that skb->data[] isn't dereferenced from a u16 ptr here since * the field may be unaligned. */ + if (!pskb_may_pull(skb, 2)) + goto discard; + if ((skb->data[0] == 0xff) && (skb->data[1] == 0x03)) skb_pull(skb, 2); @@ -709,6 +714,10 @@ discard: return 0; error: + /* Put UDP header back */ + __skb_push(skb, sizeof(struct udphdr)); + +no_tunnel: return 1; } @@ -1050,6 +1059,8 @@ static int pppol2tp_xmit(struct ppp_channel *chan, struct sk_buff *skb) /* Get routing info from the tunnel socket */ dst_release(skb->dst); skb->dst = sk_dst_get(sk_tun); + skb_orphan(skb); + skb->sk = sk_tun; /* Queue the packet to IP for output */ len = skb->len; |