From mboxrd@z Thu Jan  1 00:00:00 1970
From: David Miller <davem@davemloft.net>
Subject: Re: [PATCH] net: atm: Fix potential Spectre v1
Date: Fri, 04 May 2018 12:54:13 -0400 (EDT)
Message-ID: <20180504.125413.1422728285544894387.davem@davemloft.net>
References: <20180503184558.GA9705@embeddedor.com>
Mime-Version: 1.0
Content-Type: Text/Plain; charset=us-ascii
Content-Transfer-Encoding: 7bit
Cc: netdev@vger.kernel.org, linux-kernel@vger.kernel.org
To: gustavo@embeddedor.com
Return-path: <linux-kernel-owner@vger.kernel.org>
In-Reply-To: <20180503184558.GA9705@embeddedor.com>
Sender: linux-kernel-owner@vger.kernel.org
List-Id: netdev.vger.kernel.org

From: "Gustavo A. R. Silva" <gustavo@embeddedor.com>
Date: Thu, 3 May 2018 13:45:58 -0500

> ioc_data.dev_num can be controlled by user-space, hence leading to
> a potential exploitation of the Spectre variant 1 vulnerability.
> 
> This issue was detected with the help of Smatch:
> net/atm/lec.c:702 lec_vcc_attach() warn: potential spectre issue
> 'dev_lec'
> 
> Fix this by sanitizing ioc_data.dev_num before using it to index
> dev_lec. Also, notice that there is another instance in which array
> dev_lec is being indexed using ioc_data.dev_num at line 705:
> lec_vcc_added(netdev_priv(dev_lec[ioc_data.dev_num]),
> 
> Notice that given that speculation windows are large, the policy is
> to kill the speculation on the first load and not worry if it can be
> completed with a dependent load/store [1].
> 
> [1] https://marc.info/?l=linux-kernel&m=152449131114778&w=2
> 
> Cc: stable@vger.kernel.org
> Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>

Applied and queued up for -stable, thanks.