This is a note to let you know that I've just added the patch titled bridge: multicast: add sanity check for query source addresses
to the 3.10-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: bridge-multicast-add-sanity-check-for-query-source-addresses.patch and it can be found in the queue-3.10 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@vger.kernel.org> know about it. >From foo@baz Fri Apr 11 08:46:36 PDT 2014 From: =?UTF-8?q?Linus=20L=C3=BCssing?= <linus.luess...@web.de> Date: Tue, 4 Mar 2014 03:57:35 +0100 Subject: bridge: multicast: add sanity check for query source addresses MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit From: =?UTF-8?q?Linus=20L=C3=BCssing?= <linus.luess...@web.de> [ Upstream commit 6565b9eeef194afbb3beec80d6dd2447f4091f8c ] MLD queries are supposed to have an IPv6 link-local source address according to RFC2710, section 4 and RFC3810, section 5.1.14. This patch adds a sanity check to ignore such broken MLD queries. Without this check, such malformed MLD queries can result in a denial of service: The queries are ignored by any MLD listener therefore they will not respond with an MLD report. However, without this patch these malformed MLD queries would enable the snooping part in the bridge code, potentially shutting down the according ports towards these hosts for multicast traffic as the bridge did not learn about these listeners. Reported-by: Jan Stancek <jstan...@redhat.com> Signed-off-by: Linus Lüssing <linus.luess...@web.de> Reviewed-by: Hannes Frederic Sowa <han...@stressinduktion.org> Signed-off-by: David S. Miller <da...@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gre...@linuxfoundation.org> --- net/bridge/br_multicast.c | 6 ++++++ 1 file changed, 6 insertions(+) --- a/net/bridge/br_multicast.c +++ b/net/bridge/br_multicast.c @@ -1176,6 +1176,12 @@ static int br_ip6_multicast_query(struct br_multicast_query_received(br, port, !ipv6_addr_any(&ip6h->saddr)); + /* RFC2710+RFC3810 (MLDv1+MLDv2) require link-local source addresses */ + if (!(ipv6_addr_type(&ip6h->saddr) & IPV6_ADDR_LINKLOCAL)) { + err = -EINVAL; + goto out; + } + if (skb->len == sizeof(*mld)) { if (!pskb_may_pull(skb, sizeof(*mld))) { err = -EINVAL; Patches currently in stable-queue which might be from linus.luess...@web.de are queue-3.10/bridge-multicast-add-sanity-check-for-query-source-addresses.patch -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html