From mboxrd@z Thu Jan 1 00:00:00 1970 From: Alexander Holler Subject: bridge/netfilter: regression in 2.6.39.1 Date: Fri, 03 Jun 2011 21:21:06 +0200 Message-ID: <4DE93422.3070000@ahsoftware.de> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-15; format=flowed Content-Transfer-Encoding: 7bit Cc: Eric Dumazet , David Miller , Herbert Xu , netdev@vger.kernel.org To: linux-kernel@vger.kernel.org Return-path: Sender: linux-kernel-owner@vger.kernel.org List-Id: netdev.vger.kernel.org Hello, I'm getting a oops in the bridge code in br_change_mtu() with 2.6.39.1. The patch below seems to fix that. I'm not sure about the usage of dst_cow_metrics_generic() in fake_dst_ops, but after having a quick look at it seems to be ok to use that here. Regards, Alexander ----- From 3c1d5951af73389798afeea672ec224e195b8e8d Mon Sep 17 00:00:00 2001 From: Alexander Holler Date: Fri, 3 Jun 2011 20:43:06 +0200 Subject: [PATCH] bridge: add dst_cow_metrics_generic to fake_dst_ops Commit 42923465fb8d025a2b5153f2e7ab1e6e1058bf00 does here what it should prevent, it introduces NULL a dereference. The above commit uses dst_init_metrics() which sets the metrics as read only. As result br_change_mtu() dies in dst_metric_set() which calls dst_metrics_write_ptr() which calls dst->ops->cow_metrics() if the metrics are read only. --- net/bridge/br_netfilter.c | 1 + 1 files changed, 1 insertions(+), 0 deletions(-) diff --git a/net/bridge/br_netfilter.c b/net/bridge/br_netfilter.c index 5f9c091..de982a1 100644 --- a/net/bridge/br_netfilter.c +++ b/net/bridge/br_netfilter.c @@ -107,6 +107,7 @@ static void fake_update_pmtu(struct dst_entry *dst, u32 mtu) static struct dst_ops fake_dst_ops = { .family = AF_INET, .protocol = cpu_to_be16(ETH_P_IP), + .cow_metrics = dst_cow_metrics_generic, .update_pmtu = fake_update_pmtu, }; -- 1.7.3.4