From patchwork Wed Oct 26 14:02:01 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: David Howells X-Patchwork-Id: 9397355 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 5864660231 for ; Wed, 26 Oct 2016 14:04:05 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 32BAF29BCB for ; Wed, 26 Oct 2016 14:04:05 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 26B9129BCC; Wed, 26 Oct 2016 14:04:05 +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=-6.9 required=2.0 tests=BAYES_00,RCVD_IN_DNSWL_HI autolearn=ham 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 A7E8229BB6 for ; Wed, 26 Oct 2016 14:04:04 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755047AbcJZODg (ORCPT ); Wed, 26 Oct 2016 10:03:36 -0400 Received: from mx1.redhat.com ([209.132.183.28]:43762 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754723AbcJZOCv (ORCPT ); Wed, 26 Oct 2016 10:02:51 -0400 Received: from int-mx14.intmail.prod.int.phx2.redhat.com (int-mx14.intmail.prod.int.phx2.redhat.com [10.5.11.27]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 8FEED804F0; Wed, 26 Oct 2016 14:02:04 +0000 (UTC) Received: from warthog.procyon.org.uk (ovpn-116-17.phx2.redhat.com [10.3.116.17]) by int-mx14.intmail.prod.int.phx2.redhat.com (8.14.4/8.14.4) with ESMTP id u9QE22m9013613; Wed, 26 Oct 2016 10:02:02 -0400 Organization: Red Hat UK Ltd. 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Registered in England and Wales under Company Registration No. 3798903 Subject: [PATCH 2/3] KEYS: Sort out big_key initialisation From: David Howells To: jmorris@namei.org Cc: Peter Hlavaty , Artem Savkov , linux-kernel@vger.kernel.org, stable@vger.kernel.org, dhowells@redhat.com, linux-security-module@vger.kernel.org, keyrings@vger.kernel.org, Kirill Marinushkin Date: Wed, 26 Oct 2016 15:02:01 +0100 Message-ID: <147749052191.683.9801276962874290481.stgit@warthog.procyon.org.uk> In-Reply-To: <147749050748.683.4024891882293453809.stgit@warthog.procyon.org.uk> References: <147749050748.683.4024891882293453809.stgit@warthog.procyon.org.uk> User-Agent: StGit/0.17.1-dirty MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.68 on 10.5.11.27 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.27]); Wed, 26 Oct 2016 14:02:04 +0000 (UTC) Sender: owner-linux-security-module@vger.kernel.org Precedence: bulk List-ID: X-Virus-Scanned: ClamAV using ClamSMTP big_key has two separate initialisation functions, one that registers the key type and one that registers the crypto. If the key type fails to register, there's no problem if the crypto registers successfully because there's no way to reach the crypto except through the key type. However, if the key type registers successfully but the crypto does not, big_key_rng and big_key_blkcipher may end up set to NULL - but the code neither checks for this nor unregisters the big key key type. Furthermore, since the key type is registered before the crypto, it is theoretically possible for the kernel to try adding a big_key before the crypto is set up, leading to the same effect. Fix this by merging big_key_crypto_init() and big_key_init() and calling the resulting function late. If they're going to be encrypted, we shouldn't be creating big_keys before we have the facilities to do the encryption available. The key type registration is also moved after the crypto initialisation. The fix also includes message printing on failure. If the big_key type isn't correctly set up, simply doing: dd if=/dev/zero bs=4096 count=1 | keyctl padd big_key a @s ought to cause an oops. Fixes: 13100a72f40f5748a04017e0ab3df4cf27c809ef ('Security: Keys: Big keys stored encrypted') Signed-off-by: David Howells cc: Peter Hlavaty cc: Kirill Marinushkin cc: Artem Savkov cc: stable@vger.kernel.org --- security/keys/big_key.c | 59 +++++++++++++++++++++++++---------------------- 1 file changed, 32 insertions(+), 27 deletions(-) -- To unsubscribe from this list: send the line "unsubscribe linux-security-module" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html diff --git a/security/keys/big_key.c b/security/keys/big_key.c index c0b3030b5634..f2e1ce4af15b 100644 --- a/security/keys/big_key.c +++ b/security/keys/big_key.c @@ -9,6 +9,7 @@ * 2 of the Licence, or (at your option) any later version. */ +#define pr_fmt(fmt) "big_key: "fmt #include #include #include @@ -341,44 +342,48 @@ long big_key_read(const struct key *key, char __user *buffer, size_t buflen) */ static int __init big_key_init(void) { - return register_key_type(&key_type_big_key); -} - -/* - * Initialize big_key crypto and RNG algorithms - */ -static int __init big_key_crypto_init(void) -{ - int ret = -EINVAL; + struct crypto_skcipher *cipher; + struct crypto_rng *rng; + int ret; - /* init RNG */ - big_key_rng = crypto_alloc_rng(big_key_rng_name, 0, 0); - if (IS_ERR(big_key_rng)) { - big_key_rng = NULL; - return -EFAULT; + rng = crypto_alloc_rng(big_key_rng_name, 0, 0); + if (IS_ERR(rng)) { + pr_err("Can't alloc rng: %ld\n", PTR_ERR(rng)); + return PTR_ERR(rng); } + big_key_rng = rng; + /* seed RNG */ - ret = crypto_rng_reset(big_key_rng, NULL, crypto_rng_seedsize(big_key_rng)); - if (ret) - goto error; + ret = crypto_rng_reset(rng, NULL, crypto_rng_seedsize(rng)); + if (ret) { + pr_err("Can't reset rng: %d\n", ret); + goto error_rng; + } /* init block cipher */ - big_key_skcipher = crypto_alloc_skcipher(big_key_alg_name, - 0, CRYPTO_ALG_ASYNC); - if (IS_ERR(big_key_skcipher)) { - big_key_skcipher = NULL; - ret = -EFAULT; - goto error; + cipher = crypto_alloc_skcipher(big_key_alg_name, 0, CRYPTO_ALG_ASYNC); + if (IS_ERR(cipher)) { + ret = PTR_ERR(cipher); + pr_err("Can't alloc crypto: %d\n", ret); + goto error_rng; + } + + big_key_skcipher = cipher; + + ret = register_key_type(&key_type_big_key); + if (ret < 0) { + pr_err("Can't register type: %d\n", ret); + goto error_cipher; } return 0; -error: +error_cipher: + crypto_free_skcipher(big_key_skcipher); +error_rng: crypto_free_rng(big_key_rng); - big_key_rng = NULL; return ret; } -device_initcall(big_key_init); -late_initcall(big_key_crypto_init); +late_initcall(big_key_init);