From: Ian McDonald Date: Sat, 4 Mar 2006 01:54:46 +0000 (-0800) Subject: [DCCP] ccid3: Divide by zero fix X-Git-Tag: v2.6.16-rc6~115 X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=c09966608da7e8cad3468e925ac9062e44fee831;p=linux-2.6 [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: Ian McDonald Signed-off-by: Arnaldo Carvalho de Melo Signed-off-by: David S. Miller --- diff --git a/net/dccp/ccids/ccid3.c b/net/dccp/ccids/ccid3.c index aa68e0ab27..35d1d34754 100644 --- a/net/dccp/ccids/ccid3.c +++ b/net/dccp/ccids/ccid3.c @@ -2,7 +2,7 @@ * net/dccp/ccids/ccid3.c * * Copyright (c) 2005 The University of Waikato, Hamilton, New Zealand. - * Copyright (c) 2005 Ian McDonald + * Copyright (c) 2005-6 Ian McDonald * * 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);