From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753665AbbK2WGy (ORCPT ); Sun, 29 Nov 2015 17:06:54 -0500 Received: from wtarreau.pck.nerim.net ([62.212.114.60]:56488 "EHLO 1wt.eu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753299AbbK2WBW (ORCPT ); Sun, 29 Nov 2015 17:01:22 -0500 Message-Id: <20151129214703.302706599@1wt.eu> User-Agent: quilt/0.63-1 Date: Sun, 29 Nov 2015 22:47:12 +0100 From: Willy Tarreau To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Dan Carpenter , "David S. Miller" , Ben Hutchings , Willy Tarreau Subject: [PATCH 2.6.32 10/38] [PATCH 10/38] rds: fix an integer overflow test in rds_info_getsockopt() MIME-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-15 In-Reply-To: <8acf8256ccc72771a80b7851061027bc@local> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 2.6.32-longterm review patch. If anyone has any objections, please let me know. ------------------ commit 468b732b6f76b138c0926eadf38ac88467dcd271 upstream. "len" is a signed integer. We check that len is not negative, so it goes from zero to INT_MAX. PAGE_SIZE is unsigned long so the comparison is type promoted to unsigned long. ULONG_MAX - 4095 is a higher than INT_MAX so the condition can never be true. I don't know if this is harmful but it seems safe to limit "len" to INT_MAX - 4095. Fixes: a8c879a7ee98 ('RDS: Info and stats') Signed-off-by: Dan Carpenter Signed-off-by: David S. Miller Signed-off-by: Ben Hutchings (cherry picked from commit f3a66bdc88c3261f55b942453476e623056b92d9) Signed-off-by: Willy Tarreau --- net/rds/info.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/net/rds/info.c b/net/rds/info.c index 814a91a..0a857a0 100644 --- a/net/rds/info.c +++ b/net/rds/info.c @@ -174,7 +174,7 @@ int rds_info_getsockopt(struct socket *sock, int optname, char __user *optval, /* check for all kinds of wrapping and the like */ start = (unsigned long)optval; - if (len < 0 || len + PAGE_SIZE - 1 < len || start + len < start) { + if (len < 0 || len > INT_MAX - PAGE_SIZE + 1 || start + len < start) { ret = -EINVAL; goto out; } -- 1.7.12.2.21.g234cd45.dirty