netdev - Re: 1e918876 breaks r8169 (linux-3.18+)

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: <20150221174625.GA29681@breakpoint.cc>
Date:	Sat, 21 Feb 2015 18:46:25 +0100
From:	Florian Westphal <fw@...len.de>
To:	Eric Dumazet <eric.dumazet@...il.com>
Cc:	Florian Westphal <fw@...len.de>,
	Tomas Szepe <szepe@...erecords.com>,
	Francois Romieu <romieu@...zoreil.com>,
	Hayes Wang <hayeswang@...ltek.com>,
	Eric Dumazet <edumazet@...gle.com>,
	Tom Herbert <therbert@...gle.com>,
	"David S. Miller" <davem@...emloft.net>,
	Marco Berizzi <pupilla@...mail.com>,
	linux-kernel@...r.kernel.org, netdev <netdev@...r.kernel.org>
Subject: Re: 1e918876 breaks r8169 (linux-3.18+)

Eric Dumazet <eric.dumazet@...il.com> wrote:
> Hold on.
> 
> I believe there is one race in the way you access skb->xmit_more _after_
> 
> txd->opts1 = cpu_to_le32(status);
> 
> After this point, TX might have completed and TX completion already have
> freed skb

Hmm, I _thought_ HW would not start xmit of this descriptor/skb until after

RTL_W8(TxPoll, NPQ);

call a bit later... your patch surely looks safer though, thanks for
looking into this.

> Could Tomas try following fix ?

In addition -- Tomas, on your affected board -- did you try
turning off gso/tso?

Holger Hoffstätte mentioned on lkml that his affected r8169 nic is
stable with xmit_more+bql after disabling gso/tso on the nic

(ethtool -k $dev to display settings, "-K $dev tso off gso off" to
 disable offloads).
--
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