From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755430Ab0JBNR7 (ORCPT ); Sat, 2 Oct 2010 09:17:59 -0400 Received: from mail-fx0-f46.google.com ([209.85.161.46]:53719 "EHLO mail-fx0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754378Ab0JBNR5 (ORCPT ); Sat, 2 Oct 2010 09:17:57 -0400 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=subject:from:to:cc:content-type:date:message-id:mime-version :x-mailer:content-transfer-encoding; b=HWwcFK9oxYLj9qxpzh/Zq6dkBkQkF1HygzlAtMRmqwQCf51NtO2s7nJ6Yu6P3J6bbO bRDIbxewJAKvKr2+iGkf481TasmDnZKxHRgzy6cKLgWi+Y74vKL3suNSaTIaYqwGqKi7 uRD3TTTu8wi5xp4mjOXnXXO6217QMhD1vDlJ4= Subject: [PATCH] sysctl: fix min/max handling in __do_proc_doulongvec_minmax() From: Eric Dumazet To: Andrew Morton Cc: linux-kernel , Robin Holt , Willy Tarreau , "David S. Miller" , netdev@vger.kernel.org, James Morris , Hideaki YOSHIFUJI , "Pekka Savola (ipv6)" , netdev@vger.kernel.org, James Morris , Hideaki YOSHIFUJI , "Pekka Savola (ipv6)" , Patrick McHardy , Alexey Kuznetsov Content-Type: text/plain; charset="UTF-8" Date: Sat, 02 Oct 2010 15:17:49 +0200 Message-ID: <1286025469.2582.1806.camel@edumazet-laptop> Mime-Version: 1.0 X-Mailer: Evolution 2.30.3 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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" Signed-off-by: Eric Dumazet --- kernel/sysctl.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/kernel/sysctl.c b/kernel/sysctl.c index f88552c..4fba86d 100644 --- a/kernel/sysctl.c +++ b/kernel/sysctl.c @@ -2500,7 +2500,8 @@ static int __do_proc_doulongvec_minmax(void *data, struct ctl_table *table, int break; if (neg) continue; - if ((min && val < *min) || (max && val > *max)) + if ((table->extra1 && val < *min) || + (table->extra2 && val > *max)) continue; *i = val; } else {