netdev - Re: [PATCH RFC] unix: account skb memory to receiving socket's sk_rmem

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <20130326164233.GG29705@order.stressinduktion.org>
Date:	Tue, 26 Mar 2013 17:42:33 +0100
From:	Hannes Frederic Sowa <hannes@...essinduktion.org>
To:	Eric Dumazet <eric.dumazet@...il.com>
Cc:	netdev@...r.kernel.org, yannick@...hler.name,
	xiyou.wangcong@...il.com, davem@...emloft.net
Subject: Re: [PATCH RFC] unix: account skb memory to receiving socket's sk_rmem_alloc on sending

On Tue, Mar 26, 2013 at 08:53:38AM -0700, Eric Dumazet wrote:
> > This patch also changes the reporting of unix dgram rqueue size, as it
> > now reports not only the size of the first fragment but the amount of
> > readable memory for the socket.
> > 
> > Based on the patches from Yannick Koehler and Cong Wang.
> 
> This opens the possibility of a sender to flood a receiver, instead of
> being blocked by its own sndbuf.

Hm, the sender should get blocked by the receiver's rcvbuf. This opens the
possiblity to flood many receivers at once. But somehow this is the purpose of
this patch. Or am I missing something?

> Do we want such regression ? How many applications might rely on
> existing behavior ?

I tried to not break existing applications. The only way I can think about how
problems could arise would be by applications redoing the buffer calculations
in userspace?

I think it is a bug that a unix dgram socket can trick another dgram
socket into a situation where it cannot accept frames anymore (in case of a
ping-pong protocol).

--
To unsubscribe from this list: send the line "unsubscribe netdev" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html