Re: [PATCH] Revert "bridge: only expire the mdb entry when query is received"

[David Miller <davem@davemloft.net>]

From: Linus Lüssing <linus.luessing@web.de>
Date: Sun, 20 Oct 2013 00:58:57 +0200

> While this commit was a good attempt to fix issues occuring when no
> multicast querier is present, this commit still has two more issues:
> 
> 1) There are cases where mdb entries do not expire even if there is a
> querier present. The bridge will unnecessarily continue flooding
> multicast packets on the according ports.
> 
> 2) Never removing an mdb entry could be exploited for a Denial of
> Service by an attacker on the local link, slowly, but steadily eating up
> all memory.
> 
> Actually, this commit became obsolete with
> "bridge: disable snooping if there is no querier" (b00589af3b)
> which included fixes for a few more cases.
> 
> Therefore reverting the following commits (the commit stated in the
> commit message plus three of its follow up fixes):
> 
> ---
> Revert "bridge: update mdb expiration timer upon reports."
> This reverts commit f144febd93d5ee534fdf23505ab091b2b9088edc.
> Revert "bridge: do not call setup_timer() multiple times"
> This reverts commit 1faabf2aab1fdaa1ace4e8c829d1b9cf7bfec2f1.
> Revert "bridge: fix some kernel warning in multicast timer"
> This reverts commit c7e8e8a8f7a70b343ca1e0f90a31e35ab2d16de1.
> Revert "bridge: only expire the mdb entry when query is received"
> This reverts commit 9f00b2e7cf241fa389733d41b615efdaa2cb0f5b.
> ---

Cong, and other bridge folks, please review this revert.

Thanks.