netdev - Re: [PATCH net] amd-xgbe: Fix race between access of desc and desc index

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: <20151027.195007.1435133435434786670.davem@davemloft.net>
Date:	Tue, 27 Oct 2015 19:50:07 -0700 (PDT)
From:	David Miller <davem@...emloft.net>
To:	thomas.lendacky@....com
Cc:	netdev@...r.kernel.org, alexander.duyck@...il.com
Subject: Re: [PATCH net] amd-xgbe: Fix race between access of desc and desc
 index

From: Tom Lendacky <thomas.lendacky@....com>
Date: Mon, 26 Oct 2015 17:13:54 -0500

> During Tx cleanup it's still possible for the descriptor data to be
> read ahead of the descriptor index. A memory barrier is required between
> the read of the descriptor index and the start of the Tx cleanup loop.
> This allows a change to a lighter-weight barrier in the Tx transmit
> routine just before updating the current descriptor index.
> 
> Since the memory barrier does result in extra overhead on arm64, keep
> the previous change to not chase the current descriptor value. This
> prevents the execution of the barrier for each loop performed.
> 
> Suggested-by: Alexander Duyck <alexander.duyck@...il.com>
> Signed-off-by: Tom Lendacky <thomas.lendacky@....com>

Applied, thanks.
--
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