l2tp: Fix PPP header erasure and memory leak
Copy user data after PPP framing header. This prevents erasure of the
added PPP header and avoids leaking two bytes of uninitialised memory
at the end of skb's data buffer.
Signed-off-by: Guillaume Nault <g.nault@alphalink.fr>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/l2tp/l2tp_ppp.c b/net/l2tp/l2tp_ppp.c
index 637a341..681c626 100644
--- a/net/l2tp/l2tp_ppp.c
+++ b/net/l2tp/l2tp_ppp.c
@@ -346,12 +346,12 @@
skb_put(skb, 2);
/* Copy user data into skb */
- error = memcpy_fromiovec(skb->data, m->msg_iov, total_len);
+ error = memcpy_fromiovec(skb_put(skb, total_len), m->msg_iov,
+ total_len);
if (error < 0) {
kfree_skb(skb);
goto error_put_sess_tun;
}
- skb_put(skb, total_len);
l2tp_xmit_skb(session, skb, session->hdr_len);