From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752639Ab1BNTmp (ORCPT ); Mon, 14 Feb 2011 14:42:45 -0500 Received: from 74-93-104-97-Washington.hfc.comcastbusiness.net ([74.93.104.97]:60317 "EHLO sunset.davemloft.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750934Ab1BNTmm convert rfc822-to-8bit (ORCPT ); Mon, 14 Feb 2011 14:42:42 -0500 Date: Mon, 14 Feb 2011 11:43:18 -0800 (PST) Message-Id: <20110214.114318.112601812.davem@davemloft.net> To: eric.dumazet@gmail.com Cc: penberg@kernel.org, akpm@linux-foundation.org, netdev@vger.kernel.org, bugzilla-daemon@bugzilla.kernel.org, bugme-daemon@bugzilla.kernel.org, casteyde.christian@free.fr, xiaosuo@gmail.com, vegardno@ifi.uio.no, linux-kernel@vger.kernel.org Subject: Re: [Bugme-new] [Bug 27212] New: Warning kmemcheck: Caught 64-bit read from uninitialized memory in netlink_broadcast_filtered From: David Miller In-Reply-To: <1297704922.2996.60.camel@edumazet-laptop> References: <1295556085.2613.22.camel@edumazet-laptop> <4D393A99.9060104@kernel.org> <1297704922.2996.60.camel@edumazet-laptop> X-Mailer: Mew version 6.3 on Emacs 23.1 / Mule 6.0 (HANACHIRUSATO) Mime-Version: 1.0 Content-Type: Text/Plain; charset=iso-8859-1 Content-Transfer-Encoding: 8BIT Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Eric Dumazet Date: Mon, 14 Feb 2011 18:35:22 +0100 > Le vendredi 21 janvier 2011 à 09:49 +0200, Pekka Enberg a écrit : > >> It actually looks like a bug in SLUB+kmemcheck. The >> kmemcheck_slab_alloc() call in slab_post_alloc_hook() should use ksize() >> instead of s->objsize. SLAB seems to do the right thing already. Anyone >> care to send a patch my way? >> > > Hmm, what do you think of following patch ? > > Thanks, and sorry for the delay. > > [PATCH] slub: fix kmemcheck calls to match ksize() hints > > Recent use of ksize() in network stack (commit ca44ac38 : net: don't > reallocate skb->head unless the current one hasn't the needed extra size > or is shared) triggers kmemcheck warnings, because ksize() can return > more space than kmemcheck is aware of. > > Pekka Enberg noticed SLAB+kmemcheck is doing the right thing, while SLUB > +kmemcheck doesnt. > > Bugzilla reference #27212 > > Reported-by: Christian Casteyde > Suggested-by: Pekka Enberg > Signed-off-by: Eric Dumazet Acked-by: David S. Miller