From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Greg Kroah-Hartman , alan@lxorguk.ukuu.org.uk, Steffen Klassert , "David S. Miller" Subject: [ 70/85] ipv4: Dont report stale pmtu values to userspace Date: Thu, 25 Oct 2012 17:06:28 -0700 Message-Id: <20121026000038.155639517@linuxfoundation.org> In-Reply-To: <20121026000031.107227138@linuxfoundation.org> References: <20121026000031.107227138@linuxfoundation.org> Sender: linux-kernel-owner@vger.kernel.org List-ID: 3.6-stable review patch. If anyone has any objections, please let me know. ------------------ From: Steffen Klassert [ Upstream commit ee9a8f7ab2edf801b8b514c310455c94acc232f6 ] We report cached pmtu values even if they are already expired. Change this to not report these values after they are expired and fix a race in the expire time calculation, as suggested by Eric Dumazet. Signed-off-by: Steffen Klassert Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman --- net/ipv4/route.c | 19 +++++++++++-------- 1 file changed, 11 insertions(+), 8 deletions(-) --- a/net/ipv4/route.c +++ b/net/ipv4/route.c @@ -2187,8 +2187,18 @@ static int rt_fill_info(struct net *net, nla_put_be32(skb, RTA_GATEWAY, rt->rt_gateway)) goto nla_put_failure; + expires = rt->dst.expires; + if (expires) { + unsigned long now = jiffies; + + if (time_before(now, expires)) + expires -= now; + else + expires = 0; + } + memcpy(metrics, dst_metrics_ptr(&rt->dst), sizeof(metrics)); - if (rt->rt_pmtu) + if (rt->rt_pmtu && expires) metrics[RTAX_MTU - 1] = rt->rt_pmtu; if (rtnetlink_put_metrics(skb, metrics) < 0) goto nla_put_failure; @@ -2198,13 +2208,6 @@ static int rt_fill_info(struct net *net, goto nla_put_failure; error = rt->dst.error; - expires = rt->dst.expires; - if (expires) { - if (time_before(jiffies, expires)) - expires -= jiffies; - else - expires = 0; - } if (rt_is_input_route(rt)) { if (nla_put_u32(skb, RTA_IIF, rt->rt_iif))