Commit 7982d5e1 authored Aug 27, 2008 by Philip Love Committed by David S. Miller Aug 27, 2008

tcp: fix tcp header size miscalculation when window scale is unused



The size of the TCP header is miscalculated when the window scale ends
up being 0. Additionally, this can be induced by sending a SYN to a
passive open port with a window scale option with value 0.

Signed-off-by: Philip Love <love_phil@emc.com>
Signed-off-by: Adam Langley <agl@imperialviolet.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

parent fe439dd0

net/ipv4/tcp_output.c

+4 −2

Original line number	Diff line number	Diff line
		@@ -468,6 +468,7 @@ static unsigned tcp_syn_options(struct sock sk, struct sk_buff skb,
		}
		if (likely(sysctl_tcp_window_scaling)) {
		opts->ws = tp->rx_opt.rcv_wscale;
		if(likely(opts->ws))
		size += TCPOLEN_WSCALE_ALIGNED;
		}
		if (likely(sysctl_tcp_sack)) {
		@@ -509,6 +510,7 @@ static unsigned tcp_synack_options(struct sock *sk,

		if (likely(ireq->wscale_ok)) {
		opts->ws = ireq->rcv_wscale;
		if(likely(opts->ws))
		size += TCPOLEN_WSCALE_ALIGNED;
		}
		if (likely(doing_ts)) {