Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S966450AbcCPI2M (ORCPT ); Wed, 16 Mar 2016 04:28:12 -0400 Received: from mail.kernel.org ([198.145.29.136]:60070 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S966309AbcCPIKo (ORCPT ); Wed, 16 Mar 2016 04:10:44 -0400 From: lizf@kernel.org To: stable@vger.kernel.org Cc: linux-kernel@vger.kernel.org, Dan Carpenter , "David S. Miller" , Zefan Li Subject: [PATCH 3.4 060/107] rds: fix an integer overflow test in rds_info_getsockopt() Date: Wed, 16 Mar 2016 16:05:54 +0800 Message-Id: <1458115601-5762-60-git-send-email-lizf@kernel.org> X-Mailer: git-send-email 1.9.1 In-Reply-To: <1458115541-5712-1-git-send-email-lizf@kernel.org> References: <1458115541-5712-1-git-send-email-lizf@kernel.org> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1312 Lines: 40 From: Dan Carpenter 3.4.111-rc1 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: Zefan Li --- 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 9a6b4f6..140a44a 100644 --- a/net/rds/info.c +++ b/net/rds/info.c @@ -176,7 +176,7 @@ 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; } -- 1.9.1