[Bridge] [PATCH] bridge: multicast: add sanity check for query source addresses

[David Miller]

From: Linus Lüssing <linus.luessing at web.de>
Date: Tue,  4 Mar 2014 03:57:35 +0100

> 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 <jstancek at redhat.com>
> Signed-off-by: Linus Lüssing <linus.luessing at web.de>

Applied.