From patchwork Tue Jun 6 00:51:01 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Jason A. Donenfeld" X-Patchwork-Id: 9767783 X-Patchwork-Delegate: herbert@gondor.apana.org.au Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id D2BD960393 for ; Tue, 6 Jun 2017 00:53:46 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id C96D327968 for ; Tue, 6 Jun 2017 00:53:46 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id BE40F28435; Tue, 6 Jun 2017 00:53:46 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.0 required=2.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID, DKIM_VALID_AU, RCVD_IN_DNSWL_HI autolearn=unavailable version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 628B527F8F for ; Tue, 6 Jun 2017 00:53:46 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751268AbdFFAv6 (ORCPT ); Mon, 5 Jun 2017 20:51:58 -0400 Received: from frisell.zx2c4.com ([192.95.5.64]:57707 "EHLO frisell.zx2c4.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751192AbdFFAv5 (ORCPT ); Mon, 5 Jun 2017 20:51:57 -0400 Received: by frisell.zx2c4.com (ZX2C4 Mail Server) with ESMTP id a52d17b2; Tue, 6 Jun 2017 00:51:30 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha1; c=relaxed; d=zx2c4.com; h=from:to:cc :subject:date:message-id:in-reply-to:references; s=mail; bh=u5KC 7lW/nW9QqLlRLHdmpZ8JHIA=; b=d3MHYz6JNkl7siM69mkSRVsN/5C6eF2WdpLF ug2t06ccdVGPy6lXI12g1/jAo0EIRwN4bIhzyPb82CqiDH48G7dADyrW8PNVDKCq aV4NeE3UVuqHwFQ5RAPCyZ4IdKQgC2PLFZISHFHHYV3adPZXvzkWTR0LuOBKuX7/ vaZVZiYuARx8VbrHT6fbKpIAt2QE389MvKyeF3NdcE2a1MEfyRZBk0FugnZY9K4G T4gS2ZeJnyxHct+MaM9F0I4gSsuJ38S679ChnREMWQ/5+RBjyob8dkAheGqde40Y ZFDAZCWp6KD/Q5WdXMS8XY65BpUIL7wrqdlsrg5oUy5s8KNWig== Received: by frisell.zx2c4.com (ZX2C4 Mail Server) with ESMTPSA id 177f7f7b (TLSv1.2:ECDHE-RSA-AES256-GCM-SHA384:256:NO); Tue, 6 Jun 2017 00:51:29 +0000 (UTC) From: "Jason A. Donenfeld" To: Theodore Ts'o , Linux Crypto Mailing List , LKML , kernel-hardening@lists.openwall.com, Greg Kroah-Hartman , David Miller Cc: "Jason A. Donenfeld" , "Nicholas A. Bellinger" , Lee Duncan , Chris Leech Subject: [PATCH v3 06/13] iscsi: ensure RNG is seeded before use Date: Tue, 6 Jun 2017 02:51:01 +0200 Message-Id: <20170606005108.5646-7-Jason@zx2c4.com> X-Mailer: git-send-email 2.13.0 In-Reply-To: <20170606005108.5646-1-Jason@zx2c4.com> References: <20170606005108.5646-1-Jason@zx2c4.com> Sender: linux-crypto-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-crypto@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP It's not safe to use weak random data here, especially for the challenge response randomness. Since we're always in process context, it's safe to simply wait until we have enough randomness to carry out the authentication correctly. While we're at it, we clean up a small memleak during an error condition. Signed-off-by: Jason A. Donenfeld Cc: "Nicholas A. Bellinger" Cc: Lee Duncan Cc: Chris Leech --- drivers/target/iscsi/iscsi_target_auth.c | 14 +++++++++++--- drivers/target/iscsi/iscsi_target_login.c | 22 ++++++++++++++-------- 2 files changed, 25 insertions(+), 11 deletions(-) diff --git a/drivers/target/iscsi/iscsi_target_auth.c b/drivers/target/iscsi/iscsi_target_auth.c index 903b667f8e01..f9bc8ec6fb6b 100644 --- a/drivers/target/iscsi/iscsi_target_auth.c +++ b/drivers/target/iscsi/iscsi_target_auth.c @@ -47,18 +47,21 @@ static void chap_binaryhex_to_asciihex(char *dst, char *src, int src_len) } } -static void chap_gen_challenge( +static int chap_gen_challenge( struct iscsi_conn *conn, int caller, char *c_str, unsigned int *c_len) { + int ret; unsigned char challenge_asciihex[CHAP_CHALLENGE_LENGTH * 2 + 1]; struct iscsi_chap *chap = conn->auth_protocol; memset(challenge_asciihex, 0, CHAP_CHALLENGE_LENGTH * 2 + 1); - get_random_bytes(chap->challenge, CHAP_CHALLENGE_LENGTH); + ret = get_random_bytes_wait(chap->challenge, CHAP_CHALLENGE_LENGTH); + if (unlikely(ret)) + return ret; chap_binaryhex_to_asciihex(challenge_asciihex, chap->challenge, CHAP_CHALLENGE_LENGTH); /* @@ -69,6 +72,7 @@ static void chap_gen_challenge( pr_debug("[%s] Sending CHAP_C=0x%s\n\n", (caller) ? "server" : "client", challenge_asciihex); + return 0; } static int chap_check_algorithm(const char *a_str) @@ -143,6 +147,7 @@ static struct iscsi_chap *chap_server_open( case CHAP_DIGEST_UNKNOWN: default: pr_err("Unsupported CHAP_A value\n"); + kfree(conn->auth_protocol); return NULL; } @@ -156,7 +161,10 @@ static struct iscsi_chap *chap_server_open( /* * Generate Challenge. */ - chap_gen_challenge(conn, 1, aic_str, aic_len); + if (chap_gen_challenge(conn, 1, aic_str, aic_len) < 0) { + kfree(conn->auth_protocol); + return NULL; + } return chap; } diff --git a/drivers/target/iscsi/iscsi_target_login.c b/drivers/target/iscsi/iscsi_target_login.c index 66238477137b..5ef028c11738 100644 --- a/drivers/target/iscsi/iscsi_target_login.c +++ b/drivers/target/iscsi/iscsi_target_login.c @@ -245,22 +245,26 @@ int iscsi_check_for_session_reinstatement(struct iscsi_conn *conn) return 0; } -static void iscsi_login_set_conn_values( +static int iscsi_login_set_conn_values( struct iscsi_session *sess, struct iscsi_conn *conn, __be16 cid) { + int ret; conn->sess = sess; conn->cid = be16_to_cpu(cid); /* * Generate a random Status sequence number (statsn) for the new * iSCSI connection. */ - get_random_bytes(&conn->stat_sn, sizeof(u32)); + ret = get_random_bytes_wait(&conn->stat_sn, sizeof(u32)); + if (unlikely(ret)) + return ret; mutex_lock(&auth_id_lock); conn->auth_id = iscsit_global->auth_id++; mutex_unlock(&auth_id_lock); + return 0; } __printf(2, 3) int iscsi_change_param_sprintf( @@ -306,7 +310,11 @@ static int iscsi_login_zero_tsih_s1( return -ENOMEM; } - iscsi_login_set_conn_values(sess, conn, pdu->cid); + ret = iscsi_login_set_conn_values(sess, conn, pdu->cid); + if (unlikely(ret)) { + kfree(sess); + return ret; + } sess->init_task_tag = pdu->itt; memcpy(&sess->isid, pdu->isid, 6); sess->exp_cmd_sn = be32_to_cpu(pdu->cmdsn); @@ -497,8 +505,7 @@ static int iscsi_login_non_zero_tsih_s1( { struct iscsi_login_req *pdu = (struct iscsi_login_req *)buf; - iscsi_login_set_conn_values(NULL, conn, pdu->cid); - return 0; + return iscsi_login_set_conn_values(NULL, conn, pdu->cid); } /* @@ -554,9 +561,8 @@ static int iscsi_login_non_zero_tsih_s2( atomic_set(&sess->session_continuation, 1); spin_unlock_bh(&sess->conn_lock); - iscsi_login_set_conn_values(sess, conn, pdu->cid); - - if (iscsi_copy_param_list(&conn->param_list, + if (iscsi_login_set_conn_values(sess, conn, pdu->cid) < 0 || + iscsi_copy_param_list(&conn->param_list, conn->tpg->param_list, 0) < 0) { iscsit_tx_login_rsp(conn, ISCSI_STATUS_CLS_TARGET_ERR, ISCSI_LOGIN_STATUS_NO_RESOURCES);