From patchwork Tue Jun 6 17:47:57 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: 9769383 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 E3A766035D for ; Tue, 6 Jun 2017 17:49:07 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id DF4A32849E for ; Tue, 6 Jun 2017 17:49:07 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id D3DBF284E3; Tue, 6 Jun 2017 17:49:07 +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 AFA712849E for ; Tue, 6 Jun 2017 17:49:06 +0000 (UTC) Received: (qmail 1673 invoked by uid 550); 6 Jun 2017 17:48:30 -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 1575 invoked from network); 6 Jun 2017 17:48:27 -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=u5KC 7lW/nW9QqLlRLHdmpZ8JHIA=; b=oNZNP1caJnUNa90DPDxk+ePBHTk6GoXFyoKn uN0OHPFZsgS9c9U4jPoZxIpYDv3x+qKP3SOes2sbVnybU7a6dQ6aRP3qxlv5+FVZ iys99tPzNWFBGEtWvOK+hw9wKl2U+JAXgzZlM7ehuCoiMBoNrjUdXhiOpOW7hA2U YaqazOwtwdXaLVkBEQwQ/VWkRRgJ+dyVjbwFkfp5OXz8o/csPpMtpW4NjGc2ou3g 0uoWTJjpB5OUmXOXnYq+8lpOu4HclfgACe2n+OP/ElzBGIGRHHMSEUUZ61B4pglu olaBx76UEsKvKeHnVNGAARumOUxHMV7PYQzB+MjCpqGxV+rnWA== From: "Jason A. Donenfeld" To: Theodore Ts'o , Linux Crypto Mailing List , LKML , kernel-hardening@lists.openwall.com, Greg Kroah-Hartman , David Miller , Eric Biggers Cc: "Jason A. Donenfeld" , "Nicholas A. Bellinger" , Lee Duncan , Chris Leech Date: Tue, 6 Jun 2017 19:47:57 +0200 Message-Id: <20170606174804.31124-7-Jason@zx2c4.com> X-Mailer: git-send-email 2.13.0 In-Reply-To: <20170606174804.31124-1-Jason@zx2c4.com> References: <20170606174804.31124-1-Jason@zx2c4.com> Subject: [kernel-hardening] [PATCH v4 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 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);