netdev - Re: tcp: Do not apply TSO segment limit to non-TSO packets

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]

Date:	Fri, 02 Jan 2015 16:13:55 -0500 (EST)
From:	David Miller <davem@...emloft.net>
To:	herbert@...dor.apana.org.au
Cc:	thomas.jarosch@...ra2net.com, netdev@...r.kernel.org,
	edumazet@...gle.com, steffen.klassert@...unet.com,
	bhutchings@...arflare.com
Subject: Re: tcp: Do not apply TSO segment limit to non-TSO packets

From: Herbert Xu <herbert@...dor.apana.org.au>
Date: Thu, 1 Jan 2015 00:39:23 +1100

> Thomas Jarosch reported IPsec TCP stalls when a PMTU event occurs.
> 
> In fact the problem was completely unrelated to IPsec.  The bug is
> also reproducible if you just disable TSO/GSO.
> 
> The problem is that when the MSS goes down, existing queued packet
> on the TX queue that have not been transmitted yet all look like
> TSO packets and get treated as such.
> 
> This then triggers a bug where tcp_mss_split_point tells us to
> generate a zero-sized packet on the TX queue.  Once that happens
> we're screwed because the zero-sized packet can never be removed
> by ACKs.
> 
> Fixes: 1485348d242 ("tcp: Apply device TSO segment limit earlier")
> Reported-by: Thomas Jarosch <thomas.jarosch@...ra2net.com>
> Signed-off-by: Herbert Xu <herbert@...dor.apana.org.au>

Applied and queued up for -stable, thanks Herbert.
--
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