From mboxrd@z Thu Jan 1 00:00:00 1970 Date: Tue, 10 May 2011 11:05:40 -0700 From: Noah Meyerhans Message-ID: <20110510180540.GI6397@morgul.net> References: <20110506201234.6297.70279.reportbug@ip6-localhost> <1304995124.4065.157.camel@localhost> <20110510043833.GG6397@morgul.net> <1305031369.4065.259.camel@localhost> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="UKsZWh/ZtaJX4ozz" Content-Disposition: inline In-Reply-To: <1305031369.4065.259.camel@localhost> Subject: Re: [Bridge] Bug#625914: linux-image-2.6.38-2-amd64: bridging is not interacting well with multicast in 2.6.38-4 List-Id: Linux Ethernet Bridging List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Ben Hutchings Cc: 625914@bugs.debian.org, bridge@lists.linux-foundation.org, netdev --UKsZWh/ZtaJX4ozz Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Tue, May 10, 2011 at 01:42:49PM +0100, Ben Hutchings wrote: > > > This is pretty weird. Debian version 2.6.38-3 has a few bridging > > > changes from stable 2.6.38.3 and 2.6.38.4, but they don't look like t= hey > > > would cause this. > >=20 > > I have apparently filed the bug against the wrong version of Debian's > > kernel. 2.6.38-3 is not affected, and works as expected. The change > > was introduced in -4. That may have been clear from the report itself, > > but the report was filed against -3. I've fixed that in the BTS. >=20 > I gathered that, and then made the same mistake in writing the above! > The version with the regression, 2.6.38-4, includes the changes from > stable 2.6.38.3 and 2.6.38.4 With a little help from git bisect, I've tracked this regression down to the following commit to the stable-2.6.38.y tree: commit 5f1c356a3fadc0c19922d660da723b79bcc9aad7 Author: Herbert Xu Date: Fri Mar 18 05:27:28 2011 +0000 bridge: Reset IPCB when entering IP stack on NF_FORWARD =20 [ Upstream commit 6b1e960fdbd75dcd9bcc3ba5ff8898ff1ad30b6e ] =20 Whenever we enter the IP stack proper from bridge netfilter we need to ensure that the skb is in a form the IP stack expects it to be in. =20 The entry point on NF_FORWARD did not meet the requirements of the IP stack, therefore leading to potential crashes/panics. =20 This patch fixes the problem. =20 Signed-off-by: Herbert Xu Acked-by: Stephen Hemminger Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman The diff is diff --git a/net/bridge/br_netfilter.c b/net/bridge/br_netfilter.c index 4b5b66d..49d50ea 100644 --- a/net/bridge/br_netfilter.c +++ b/net/bridge/br_netfilter.c @@ -741,6 +741,9 @@ static unsigned int br_nf_forward_ip(unsigned int hook, struct sk_buff *skb, nf_bridge->mask |=3D BRNF_PKT_TYPE; } =20 + if (br_parse_ip_options(skb)) + return NF_DROP; + /* The physdev module checks on this */ nf_bridge->mask |=3D BRNF_BRIDGED; nf_bridge->physoutdev =3D skb->dev; If I revert this change, network connectivity functions as expected for the VMs on this host. I don't know enough about this change or the problem it was supposed to solve to be able to guess about what's going wrong. noah --UKsZWh/ZtaJX4ozz Content-Type: application/pgp-signature; name="signature.asc" Content-Description: Digital signature Content-Disposition: inline -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.9 (GNU/Linux) iD8DBQFNyX5zYrVLjBFATsMRAmb/AJwNHxuXZFtWlm6PdQ2VrvwU1YyGVgCfdA+/ 1IX2tmqcBDRQGGhkwY6KyzE= =ThAF -----END PGP SIGNATURE----- --UKsZWh/ZtaJX4ozz--