From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 9122BC5479D for ; Wed, 11 Jan 2023 21:23:04 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232854AbjAKVXD (ORCPT ); Wed, 11 Jan 2023 16:23:03 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:41140 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233181AbjAKVXA (ORCPT ); Wed, 11 Jan 2023 16:23:00 -0500 Received: from mail.netfilter.org (mail.netfilter.org [217.70.188.207]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id A3039633C for ; Wed, 11 Jan 2023 13:22:58 -0800 (PST) From: Pablo Neira Ayuso To: netfilter-devel@vger.kernel.org Subject: [PATCH net 2/3] netfilter: ipset: Fix overflow before widen in the bitmap_ip_create() function. Date: Wed, 11 Jan 2023 22:22:50 +0100 Message-Id: <20230111212251.193032-3-pablo@netfilter.org> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20230111212251.193032-1-pablo@netfilter.org> References: <20230111212251.193032-1-pablo@netfilter.org> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: netfilter-devel@vger.kernel.org From: Gavrilov Ilia When first_ip is 0, last_ip is 0xFFFFFFFF, and netmask is 31, the value of an arithmetic expression 2 << (netmask - mask_bits - 1) is subject to overflow due to a failure casting operands to a larger data type before performing the arithmetic. Note that it's harmless since the value will be checked at the next step. Found by InfoTeCS on behalf of Linux Verification Center (linuxtesting.org) with SVACE. Fixes: b9fed748185a ("netfilter: ipset: Check and reject crazy /0 input parameters") Signed-off-by: Ilia.Gavrilov Reviewed-by: Simon Horman Signed-off-by: Pablo Neira Ayuso --- net/netfilter/ipset/ip_set_bitmap_ip.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/net/netfilter/ipset/ip_set_bitmap_ip.c b/net/netfilter/ipset/ip_set_bitmap_ip.c index a8ce04a4bb72..e4fa00abde6a 100644 --- a/net/netfilter/ipset/ip_set_bitmap_ip.c +++ b/net/netfilter/ipset/ip_set_bitmap_ip.c @@ -308,8 +308,8 @@ bitmap_ip_create(struct net *net, struct ip_set *set, struct nlattr *tb[], return -IPSET_ERR_BITMAP_RANGE; pr_debug("mask_bits %u, netmask %u\n", mask_bits, netmask); - hosts = 2 << (32 - netmask - 1); - elements = 2 << (netmask - mask_bits - 1); + hosts = 2U << (32 - netmask - 1); + elements = 2UL << (netmask - mask_bits - 1); } if (elements > IPSET_BITMAP_MAX_RANGE + 1) return -IPSET_ERR_BITMAP_RANGE_SIZE; -- 2.30.2