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Commit c0996660 authored by Ian McDonald's avatar Ian McDonald Committed by David S. Miller
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[DCCP] ccid3: Divide by zero fix 



In rare circumstances 0 is returned by dccp_li_hist_calc_i_mean which
leads to a divide by zero in ccid3_hc_rx_packet_recv. Explicitly check
for zero return now. Update copyright notice at same time.

Found by Arnaldo.

Signed-off-by: default avatarIan McDonald <imcdnzl@gmail.com>
Signed-off-by: default avatarArnaldo Carvalho de Melo <acme@mandriva.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent c027f5f9

net/dccp/ccids/ccid3.c

+7 −3
Original line number Diff line number Diff line
@@ -2,7 +2,7 @@ 
 *  net/dccp/ccids/ccid3.c

 *

 *  Copyright (c) 2005 The University of Waikato, Hamilton, New Zealand.

 *  Copyright (c) 2005 Ian McDonald <iam4@cs.waikato.ac.nz>

 *  Copyright (c) 2005-6 Ian McDonald <imcdnzl@gmail.com>

 *

 *  An implementation of the DCCP protocol

 *
@@ -1033,9 +1033,13 @@ static void ccid3_hc_rx_packet_recv(struct sock *sk, struct sk_buff *skb) 
	p_prev = hcrx->ccid3hcrx_p;

	

	/* Calculate loss event rate */

	if (!list_empty(&hcrx->ccid3hcrx_li_hist))

	if (!list_empty(&hcrx->ccid3hcrx_li_hist)) {

		u32 i_mean = dccp_li_hist_calc_i_mean(&hcrx->ccid3hcrx_li_hist);



		/* Scaling up by 1000000 as fixed decimal */

		hcrx->ccid3hcrx_p = 1000000 / dccp_li_hist_calc_i_mean(&hcrx->ccid3hcrx_li_hist);

		if (i_mean != 0)

			hcrx->ccid3hcrx_p = 1000000 / i_mean;

	}



	if (hcrx->ccid3hcrx_p > p_prev) {

		ccid3_hc_rx_send_feedback(sk);