Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S964959AbaFXP4A (ORCPT ); Tue, 24 Jun 2014 11:56:00 -0400 Received: from mail.linuxfoundation.org ([140.211.169.12]:33277 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755309AbaFXPz5 (ORCPT ); Tue, 24 Jun 2014 11:55:57 -0400 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Tejas Vaykole , Nicholas Bellinger Subject: [PATCH 3.15 03/61] iscsi-target: Reject mutual authentication with reflected CHAP_C Date: Tue, 24 Jun 2014 11:50:46 -0400 Message-Id: <20140624154952.934935636@linuxfoundation.org> X-Mailer: git-send-email 2.0.0 In-Reply-To: <20140624154952.751713761@linuxfoundation.org> References: <20140624154952.751713761@linuxfoundation.org> User-Agent: quilt/0.63-1 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.15-stable review patch. If anyone has any objections, please let me know. ------------------ From: Nicholas Bellinger commit 1d2b60a5545942b1376cb48c1d55843d71e3a08f upstream. This patch adds an explicit check in chap_server_compute_md5() to ensure the CHAP_C value received from the initiator during mutual authentication does not match the original CHAP_C provided by the target. This is in line with RFC-3720, section 8.2.1: Originators MUST NOT reuse the CHAP challenge sent by the Responder for the other direction of a bidirectional authentication. Responders MUST check for this condition and close the iSCSI TCP connection if it occurs. Reported-by: Tejas Vaykole Signed-off-by: Nicholas Bellinger Signed-off-by: Greg Kroah-Hartman --- drivers/target/iscsi/iscsi_target_auth.c | 10 ++++++++++ 1 file changed, 10 insertions(+) --- a/drivers/target/iscsi/iscsi_target_auth.c +++ b/drivers/target/iscsi/iscsi_target_auth.c @@ -314,6 +314,16 @@ static int chap_server_compute_md5( goto out; } /* + * During mutual authentication, the CHAP_C generated by the + * initiator must not match the original CHAP_C generated by + * the target. + */ + if (!memcmp(challenge_binhex, chap->challenge, CHAP_CHALLENGE_LENGTH)) { + pr_err("initiator CHAP_C matches target CHAP_C, failing" + " login attempt\n"); + goto out; + } + /* * Generate CHAP_N and CHAP_R for mutual authentication. */ tfm = crypto_alloc_hash("md5", 0, CRYPTO_ALG_ASYNC); -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/