From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.0 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 5E5B8C43381 for ; Fri, 22 Mar 2019 12:13:38 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 2C50E20830 for ; Fri, 22 Mar 2019 12:13:38 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1553256818; bh=3G89iVRL/cRyx4cpNBf/i/egoSOlvEoehkY2wUogK0s=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=H0LESRIpvaYYz5yvTFXltPynRQrsfTSAVnz3YfO7wycwdQE/fXLpClA/OUZvQkVHm qRgGUiRXYy44GGcxyZVmj0+UtPBysQmjugNhoBDJEOqX5c1I1PeJRFJOyt5jzJJpHe UlKpo7kwEhHxVZNzDEBtV+CK499WRo6Ha3WP+rLA= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2389784AbfCVMNg (ORCPT ); Fri, 22 Mar 2019 08:13:36 -0400 Received: from mail.kernel.org ([198.145.29.99]:51814 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2389770AbfCVMNd (ORCPT ); Fri, 22 Mar 2019 08:13:33 -0400 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id BC6CC20830; Fri, 22 Mar 2019 12:13:31 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1553256812; bh=3G89iVRL/cRyx4cpNBf/i/egoSOlvEoehkY2wUogK0s=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=QXEFelXYVJprwHoa1VfhH05eQx/y8FJwBkrEqBqNvdUTJ5Uol7QkRTahCXO6ospLJ +90RuUX45cs/SZ5RsfDM7eI30wP8msWJ7G0bXxARSpH0kjy6iVrOOtf83NuRagY+00 32MSGdoANO8Q4u9lU3oiKZPfKBGejx8JSMse8KzE= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Eric Biggers , Herbert Xu Subject: [PATCH 5.0 044/238] crypto: skcipher - set CRYPTO_TFM_NEED_KEY if ->setkey() fails Date: Fri, 22 Mar 2019 12:14:23 +0100 Message-Id: <20190322111301.005594456@linuxfoundation.org> X-Mailer: git-send-email 2.21.0 In-Reply-To: <20190322111258.383569278@linuxfoundation.org> References: <20190322111258.383569278@linuxfoundation.org> User-Agent: quilt/0.65 X-stable: review X-Patchwork-Hint: ignore MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 5.0-stable review patch. If anyone has any objections, please let me know. ------------------ From: Eric Biggers commit b1f6b4bf416b49f00f3abc49c639371cdecaaad1 upstream. Some algorithms have a ->setkey() method that is not atomic, in the sense that setting a key can fail after changes were already made to the tfm context. In this case, if a key was already set the tfm can end up in a state that corresponds to neither the old key nor the new key. For example, in lrw.c, if gf128mul_init_64k_bbe() fails due to lack of memory, then priv::table will be left NULL. After that, encryption with that tfm will cause a NULL pointer dereference. It's not feasible to make all ->setkey() methods atomic, especially ones that have to key multiple sub-tfms. Therefore, make the crypto API set CRYPTO_TFM_NEED_KEY if ->setkey() fails and the algorithm requires a key, to prevent the tfm from being used until a new key is set. [Cc stable mainly because when introducing the NEED_KEY flag I changed AF_ALG to rely on it; and unlike in-kernel crypto API users, AF_ALG previously didn't have this problem. So these "incompletely keyed" states became theoretically accessible via AF_ALG -- though, the opportunities for causing real mischief seem pretty limited.] Fixes: f8d33fac8480 ("crypto: skcipher - prevent using skciphers without setting key") Cc: # v4.16+ Signed-off-by: Eric Biggers Signed-off-by: Herbert Xu Signed-off-by: Greg Kroah-Hartman --- crypto/skcipher.c | 27 ++++++++++++++++++--------- 1 file changed, 18 insertions(+), 9 deletions(-) --- a/crypto/skcipher.c +++ b/crypto/skcipher.c @@ -585,6 +585,12 @@ static unsigned int crypto_skcipher_exts return crypto_alg_extsize(alg); } +static void skcipher_set_needkey(struct crypto_skcipher *tfm) +{ + if (tfm->keysize) + crypto_skcipher_set_flags(tfm, CRYPTO_TFM_NEED_KEY); +} + static int skcipher_setkey_blkcipher(struct crypto_skcipher *tfm, const u8 *key, unsigned int keylen) { @@ -598,8 +604,10 @@ static int skcipher_setkey_blkcipher(str err = crypto_blkcipher_setkey(blkcipher, key, keylen); crypto_skcipher_set_flags(tfm, crypto_blkcipher_get_flags(blkcipher) & CRYPTO_TFM_RES_MASK); - if (err) + if (unlikely(err)) { + skcipher_set_needkey(tfm); return err; + } crypto_skcipher_clear_flags(tfm, CRYPTO_TFM_NEED_KEY); return 0; @@ -677,8 +685,7 @@ static int crypto_init_skcipher_ops_blkc skcipher->ivsize = crypto_blkcipher_ivsize(blkcipher); skcipher->keysize = calg->cra_blkcipher.max_keysize; - if (skcipher->keysize) - crypto_skcipher_set_flags(skcipher, CRYPTO_TFM_NEED_KEY); + skcipher_set_needkey(skcipher); return 0; } @@ -698,8 +705,10 @@ static int skcipher_setkey_ablkcipher(st crypto_skcipher_set_flags(tfm, crypto_ablkcipher_get_flags(ablkcipher) & CRYPTO_TFM_RES_MASK); - if (err) + if (unlikely(err)) { + skcipher_set_needkey(tfm); return err; + } crypto_skcipher_clear_flags(tfm, CRYPTO_TFM_NEED_KEY); return 0; @@ -776,8 +785,7 @@ static int crypto_init_skcipher_ops_ablk sizeof(struct ablkcipher_request); skcipher->keysize = calg->cra_ablkcipher.max_keysize; - if (skcipher->keysize) - crypto_skcipher_set_flags(skcipher, CRYPTO_TFM_NEED_KEY); + skcipher_set_needkey(skcipher); return 0; } @@ -820,8 +828,10 @@ static int skcipher_setkey(struct crypto else err = cipher->setkey(tfm, key, keylen); - if (err) + if (unlikely(err)) { + skcipher_set_needkey(tfm); return err; + } crypto_skcipher_clear_flags(tfm, CRYPTO_TFM_NEED_KEY); return 0; @@ -852,8 +862,7 @@ static int crypto_skcipher_init_tfm(stru skcipher->ivsize = alg->ivsize; skcipher->keysize = alg->max_keysize; - if (skcipher->keysize) - crypto_skcipher_set_flags(skcipher, CRYPTO_TFM_NEED_KEY); + skcipher_set_needkey(skcipher); if (alg->exit) skcipher->base.exit = crypto_skcipher_exit_tfm;