From mboxrd@z Thu Jan  1 00:00:00 1970
From: David Miller <davem@davemloft.net>
Subject: Re: [net 1/1] tipc: fix skb truesize/datasize
 ratio control
Date: Thu, 08 Feb 2018 15:31:15 -0500 (EST)
Message-ID: <20180208.153115.260191898373353330.davem@davemloft.net>
References: <1518106585-11064-1-git-send-email-jon.maloy@ericsson.com>
Mime-Version: 1.0
Content-Type: text/plain; charset="us-ascii"
Content-Transfer-Encoding: 7bit
Cc: netdev@vger.kernel.org, tipc-discussion@lists.sourceforge.net,
 hoang.h.le@dektech.com.au, mohan.krishna.ghanta.krishnamurthy@ericsson.com
To: jon.maloy@ericsson.com
Return-path: <tipc-discussion-bounces@lists.sourceforge.net>
In-Reply-To: <1518106585-11064-1-git-send-email-jon.maloy@ericsson.com>
List-Unsubscribe: <https://lists.sourceforge.net/lists/options/tipc-discussion>,
 <mailto:tipc-discussion-request@lists.sourceforge.net?subject=unsubscribe>
List-Archive: <http://sourceforge.net/mailarchive/forum.php?forum_name=tipc-discussion>
List-Post: <mailto:tipc-discussion@lists.sourceforge.net>
List-Help: <mailto:tipc-discussion-request@lists.sourceforge.net?subject=help>
List-Subscribe: <https://lists.sourceforge.net/lists/listinfo/tipc-discussion>,
 <mailto:tipc-discussion-request@lists.sourceforge.net?subject=subscribe>
Errors-To: tipc-discussion-bounces@lists.sourceforge.net
List-Id: netdev.vger.kernel.org

From: Jon Maloy <jon.maloy@ericsson.com>
Date: Thu, 8 Feb 2018 17:16:25 +0100

> From: Hoang Le <hoang.h.le@dektek.com.au>
> 
> In commit d618d09a68e4 ("tipc: enforce valid ratio between skb truesize
> and contents") we introduced a test for ensuring that the condition
> truesize/datasize <= 4 is true for a received buffer. Unfortunately this
> test has two problems.
> 
> - Because of the integer arithmetics the test
>   if (skb->truesize / buf_roundup_len(skb) > 4) will miss all
>   ratios [4 < ratio < 5], which was not the intention.
> - The buffer returned by skb_copy() inherits skb->truesize of the
>   original buffer, which doesn't help the situation at all.
> 
> In this commit, we change the ratio condition and replace skb_copy()
> with a call to skb_copy_expand() to finally get this right.
> 
> Acked-by: Jon Maloy <jon.maloy@ericsson.com>
> Signed-off-by: Jon Maloy <jon.maloy@ericsson.com>

Applied, thanks Jon.

------------------------------------------------------------------------------
Check out the vibrant tech community on one of the world's most
engaging tech sites, Slashdot.org! http://sdm.link/slashdot