From patchwork Wed Jun 7 23:26:00 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: 9773273 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 1A2A660234 for ; Wed, 7 Jun 2017 23:27:15 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 0DF492847A for ; Wed, 7 Jun 2017 23:27:15 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 029BB2848F; Wed, 7 Jun 2017 23:27:14 +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=-4.1 required=2.0 tests=BAYES_00,DKIM_SIGNED, RCVD_IN_DNSWL_MED,T_DKIM_INVALID autolearn=ham version=3.3.1 Received: from mother.openwall.net (mother.openwall.net [195.42.179.200]) by mail.wl.linuxfoundation.org (Postfix) with SMTP id CD6EA2848D for ; Wed, 7 Jun 2017 23:27:13 +0000 (UTC) Received: (qmail 26258 invoked by uid 550); 7 Jun 2017 23:26:31 -0000 Mailing-List: contact kernel-hardening-help@lists.openwall.com; run by ezmlm Precedence: bulk List-Post: List-Help: List-Unsubscribe: List-Subscribe: List-ID: Delivered-To: mailing list kernel-hardening@lists.openwall.com Received: (qmail 26137 invoked from network); 7 Jun 2017 23:26:27 -0000 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=Kn05 SRXfECPWBf+C2L2fhPXL064=; b=nrkvr+Q7iec4Zny+vwys/yiH0cpjykKzgkHL kG5ATTZLKb6JFDEeYv1Kad3ktrUpFbRpQnkwlRWfcBgUNpvmcS4JaNhUuHQw1Gf7 mb6CJDLdpsF17LlmpVVhXpWOhTH+CMLQlLxcG6svTN7u7mBl4gcCl1DBXNXh3H56 YI4Hxf1KzWj+F7uzx7F9DhqgNjJCMKFipzGipRxbtPS/cl8adoLpra+wPiLgSWoG YbwnNDk+bqBZBjQtgkwiSt8YQNgoI13dr1CGFr9rlVpSvzX/mCyaPEWYDXOXIfgo NFI4a9ShVFN+eSIJbCFeDQEKXkV6t2d/7Qpv9FyRnXBwEZheTg== From: "Jason A. Donenfeld" To: Theodore Ts'o , Linux Crypto Mailing List , LKML , kernel-hardening@lists.openwall.com, Greg Kroah-Hartman , Eric Biggers , Linus Torvalds , David Miller Cc: "Jason A. Donenfeld" , "Nicholas A. Bellinger" , Lee Duncan , Chris Leech Date: Thu, 8 Jun 2017 01:26:00 +0200 Message-Id: <20170607232607.26870-7-Jason@zx2c4.com> In-Reply-To: <20170607232607.26870-1-Jason@zx2c4.com> References: <20170607232607.26870-1-Jason@zx2c4.com> Subject: [kernel-hardening] [PATCH v5 06/13] iscsi: ensure RNG is seeded before use 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 92b96b51d506..e9bdc8b86e7d 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);