From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753575Ab0JGQ7M (ORCPT ); Thu, 7 Oct 2010 12:59:12 -0400 Received: from mail-fx0-f46.google.com ([209.85.161.46]:32963 "EHLO mail-fx0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751882Ab0JGQ7K (ORCPT ); Thu, 7 Oct 2010 12:59:10 -0400 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=subject:from:to:cc:in-reply-to:references:content-type:date :message-id:mime-version:x-mailer:content-transfer-encoding; b=EzmZ1eN3lGlLNCawlTLXUEWUawt8euRB36oF12TWVCljdPWBpCWmbCv/IVpSO99QQz TRM2oPVZU76YiwmGZ0RbHzLhQuvHHjVnSsCM+ObGfWDGwxlS8RpokNTGtV7yX2G/9kNs mtK1C1jq2N89uARpbTRPRvWWtwrjDsR2WJsMM= Subject: Re: [PATCH] sysctl: fix min/max handling in __do_proc_doulongvec_minmax() From: Eric Dumazet To: "Eric W. Biederman" , Andrew Morton Cc: =?ISO-8859-1?Q?Am=E9rico?= Wang , Robin Holt , linux-kernel , Willy Tarreau , "David S. Miller" , netdev@vger.kernel.org, James Morris , "Pekka Savola (ipv6)" , Patrick McHardy , Alexey Kuznetsov In-Reply-To: References: <1286025469.2582.1806.camel@edumazet-laptop> <20101004085913.GR14068@sgi.com> <1286183058.18293.26.camel@edumazet-laptop> <20101004093439.GG5189@cr0.nay.redhat.com> <1286187030.18293.33.camel@edumazet-laptop> <20101004103545.GJ5189@cr0.nay.redhat.com> <1286188701.18293.57.camel@edumazet-laptop> <20101005130117.GK5170@cr0.nay.redhat.com> <20101007071859.GD5471@cr0.nay.redhat.com> <20101007092538.GE5471@cr0.nay.redhat.com> <1286445081.2912.15.camel@edumazet-laptop> Content-Type: text/plain; charset="UTF-8" Date: Thu, 07 Oct 2010 18:59:03 +0200 Message-ID: <1286470743.2912.276.camel@edumazet-laptop> Mime-Version: 1.0 X-Mailer: Evolution 2.30.3 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Le jeudi 07 octobre 2010 à 09:37 -0700, Eric W. Biederman a écrit : > The difference between long handling and int handling is a > usability issue. I don't expect we will be exporting new > vectors via sysctl, so the conversion of a handful of vectors > from int to long is where this is most likely to be used. > > I skimmed through all of what I presume are the current users > aka linux-2.6.36-rcX and there don't appear to be any users > of proc_dounlongvec_minmax that use it's vector properties there. > > Which doubly tells me that incrementing the min and max pointers > is not what we want to do. > Thats fine by me, thanks Eric. Andrew, please remove previous patch from your tree and replace it by following one : [PATCH v2] sysctl: fix min/max handling in __do_proc_doulongvec_minmax() When proc_doulongvec_minmax() is used with an array of longs, and no min/max check requested (.extra1 or .extra2 being NULL), we dereference a NULL pointer for the second element of the array. Noticed while doing some changes in network stack for the "16TB problem" Fix is to not change min & max pointers in __do_proc_doulongvec_minmax(), so that all elements of the vector share an unique min/max limit, like proc_dointvec_minmax(). Signed-off-by: Eric Dumazet --- kernel/sysctl.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/kernel/sysctl.c b/kernel/sysctl.c index f88552c..8e45451 100644 --- a/kernel/sysctl.c +++ b/kernel/sysctl.c @@ -2485,7 +2485,7 @@ static int __do_proc_doulongvec_minmax(void *data, struct ctl_table *table, int kbuf[left] = 0; } - for (; left && vleft--; i++, min++, max++, first=0) { + for (; left && vleft--; i++, first=0) { unsigned long val; if (write) {