From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.linuxfoundation.org ([140.211.169.12]:38192 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728216AbeICVOl (ORCPT ); Mon, 3 Sep 2018 17:14:41 -0400 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, "yujuan.qi" , Paul Moore , "David S. Miller" Subject: [PATCH 4.4 02/80] Cipso: cipso_v4_optptr enter infinite loop Date: Mon, 3 Sep 2018 18:48:40 +0200 Message-Id: <20180903164934.273092616@linuxfoundation.org> In-Reply-To: <20180903164934.171677301@linuxfoundation.org> References: <20180903164934.171677301@linuxfoundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: stable-owner@vger.kernel.org List-ID: 4.4-stable review patch. If anyone has any objections, please let me know. ------------------ From: yujuan.qi commit 40413955ee265a5e42f710940ec78f5450d49149 upstream. in for(),if((optlen > 0) && (optptr[1] == 0)), enter infinite loop. Test: receive a packet which the ip length > 20 and the first byte of ip option is 0, produce this issue Signed-off-by: yujuan.qi Acked-by: Paul Moore Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman --- net/ipv4/cipso_ipv4.c | 12 ++++++++++-- 1 file changed, 10 insertions(+), 2 deletions(-) --- a/net/ipv4/cipso_ipv4.c +++ b/net/ipv4/cipso_ipv4.c @@ -1593,9 +1593,17 @@ unsigned char *cipso_v4_optptr(const str int taglen; for (optlen = iph->ihl*4 - sizeof(struct iphdr); optlen > 0; ) { - if (optptr[0] == IPOPT_CIPSO) + switch (optptr[0]) { + case IPOPT_CIPSO: return optptr; - taglen = optptr[1]; + case IPOPT_END: + return NULL; + case IPOPT_NOOP: + taglen = 1; + break; + default: + taglen = optptr[1]; + } optlen -= taglen; optptr += taglen; }