Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753501AbaFWIzU (ORCPT ); Mon, 23 Jun 2014 04:55:20 -0400 Received: from ip4-83-240-18-248.cust.nbox.cz ([83.240.18.248]:55511 "EHLO ip4-83-240-18-248.cust.nbox.cz" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752518AbaFWIc2 (ORCPT ); Mon, 23 Jun 2014 04:32:28 -0400 From: Jiri Slaby To: stable@vger.kernel.org Cc: linux-kernel@vger.kernel.org, Nicholas Bellinger , Jiri Slaby Subject: [PATCH 3.12 084/111] iscsi-target: Reject mutual authentication with reflected CHAP_C Date: Mon, 23 Jun 2014 10:31:59 +0200 Message-Id: <4eed5cf5e6d06f1ef7d786ed3f43da55112cb96c.1403512281.git.jslaby@suse.cz> X-Mailer: git-send-email 2.0.0 In-Reply-To: <55d5f044a1fc96a74e4470e318c0a24f27a9ab7e.1403512280.git.jslaby@suse.cz> References: <55d5f044a1fc96a74e4470e318c0a24f27a9ab7e.1403512280.git.jslaby@suse.cz> In-Reply-To: References: Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Nicholas Bellinger 3.12-stable review patch. If anyone has any objections, please let me know. =============== 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: Jiri Slaby --- drivers/target/iscsi/iscsi_target_auth.c | 10 ++++++++++ 1 file changed, 10 insertions(+) diff --git a/drivers/target/iscsi/iscsi_target_auth.c b/drivers/target/iscsi/iscsi_target_auth.c index 3e80188558cd..b25bba5f26b2 100644 --- 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); -- 2.0.0 -- 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/