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_HELO_NONE,SPF_PASS,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 F1B7EC04AAF for ; Mon, 20 May 2019 12:27:06 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id BDF5220645 for ; Mon, 20 May 2019 12:27:06 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1558355226; bh=rmHVYPOlnN/vpU5p3SZu4V8v2GRlgsYkk6Zj1BVORRs=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=WCXiJIf5SZaRoxz1YKiLCHKU6YeAhmOH+D53jPxNZ8y+UhD1+PMOxbC8u31rKJq5M vnClAFQCHnfNA5AQ3MXn2+1IszrC7MtnuHYLVrQtwebt+NkcB7CQojjJeLZ1NXs1r8 NufNSpqfa2ZdU4jBDWrKtgbr8GIW8oJxl4/mF5u0= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2389043AbfETM1F (ORCPT ); Mon, 20 May 2019 08:27:05 -0400 Received: from mail.kernel.org ([198.145.29.99]:42558 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2389029AbfETM1E (ORCPT ); Mon, 20 May 2019 08:27:04 -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 E769A21019; Mon, 20 May 2019 12:27:02 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1558355223; bh=rmHVYPOlnN/vpU5p3SZu4V8v2GRlgsYkk6Zj1BVORRs=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=GrLdcIBSu3yrlBYONZT02MZGqvJla5Xsqmbgw1ZJZTZNUqP8HSjR75tisEzOyazJc se02zElkRKa88Kvy69MM5RdCJqbYyRxWeAM7knS5Q5UaAPx66Rwf+x8PG3xBmsWxqV 85D94qcgF1mJ6Yyt2W28XdpAkW+hRU2r+QgzAUzY= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Eric Biggers , Herbert Xu Subject: [PATCH 5.0 037/123] crypto: gcm - fix incompatibility between "gcm" and "gcm_base" Date: Mon, 20 May 2019 14:13:37 +0200 Message-Id: <20190520115247.199272863@linuxfoundation.org> X-Mailer: git-send-email 2.21.0 In-Reply-To: <20190520115245.439864225@linuxfoundation.org> References: <20190520115245.439864225@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Eric Biggers commit f699594d436960160f6d5ba84ed4a222f20d11cd upstream. GCM instances can be created by either the "gcm" template, which only allows choosing the block cipher, e.g. "gcm(aes)"; or by "gcm_base", which allows choosing the ctr and ghash implementations, e.g. "gcm_base(ctr(aes-generic),ghash-generic)". However, a "gcm_base" instance prevents a "gcm" instance from being registered using the same implementations. Nor will the instance be found by lookups of "gcm". This can be used as a denial of service. Moreover, "gcm_base" instances are never tested by the crypto self-tests, even if there are compatible "gcm" tests. The root cause of these problems is that instances of the two templates use different cra_names. Therefore, fix these problems by making "gcm_base" instances set the same cra_name as "gcm" instances, e.g. "gcm(aes)" instead of "gcm_base(ctr(aes-generic),ghash-generic)". This requires extracting the block cipher name from the name of the ctr algorithm. It also requires starting to verify that the algorithms are really ctr and ghash, not something else entirely. But it would be bizarre if anyone were actually using non-gcm-compatible algorithms with gcm_base, so this shouldn't break anyone in practice. Fixes: d00aa19b507b ("[CRYPTO] gcm: Allow block cipher parameter") Cc: stable@vger.kernel.org Signed-off-by: Eric Biggers Signed-off-by: Herbert Xu Signed-off-by: Greg Kroah-Hartman --- crypto/gcm.c | 34 +++++++++++----------------------- 1 file changed, 11 insertions(+), 23 deletions(-) --- a/crypto/gcm.c +++ b/crypto/gcm.c @@ -597,7 +597,6 @@ static void crypto_gcm_free(struct aead_ static int crypto_gcm_create_common(struct crypto_template *tmpl, struct rtattr **tb, - const char *full_name, const char *ctr_name, const char *ghash_name) { @@ -638,7 +637,8 @@ static int crypto_gcm_create_common(stru goto err_free_inst; err = -EINVAL; - if (ghash->digestsize != 16) + if (strcmp(ghash->base.cra_name, "ghash") != 0 || + ghash->digestsize != 16) goto err_drop_ghash; crypto_set_skcipher_spawn(&ctx->ctr, aead_crypto_instance(inst)); @@ -650,24 +650,24 @@ static int crypto_gcm_create_common(stru ctr = crypto_spawn_skcipher_alg(&ctx->ctr); - /* We only support 16-byte blocks. */ + /* The skcipher algorithm must be CTR mode, using 16-byte blocks. */ err = -EINVAL; - if (crypto_skcipher_alg_ivsize(ctr) != 16) + if (strncmp(ctr->base.cra_name, "ctr(", 4) != 0 || + crypto_skcipher_alg_ivsize(ctr) != 16 || + ctr->base.cra_blocksize != 1) goto out_put_ctr; - /* Not a stream cipher? */ - if (ctr->base.cra_blocksize != 1) + err = -ENAMETOOLONG; + if (snprintf(inst->alg.base.cra_name, CRYPTO_MAX_ALG_NAME, + "gcm(%s", ctr->base.cra_name + 4) >= CRYPTO_MAX_ALG_NAME) goto out_put_ctr; - err = -ENAMETOOLONG; if (snprintf(inst->alg.base.cra_driver_name, CRYPTO_MAX_ALG_NAME, "gcm_base(%s,%s)", ctr->base.cra_driver_name, ghash_alg->cra_driver_name) >= CRYPTO_MAX_ALG_NAME) goto out_put_ctr; - memcpy(inst->alg.base.cra_name, full_name, CRYPTO_MAX_ALG_NAME); - inst->alg.base.cra_flags = (ghash->base.cra_flags | ctr->base.cra_flags) & CRYPTO_ALG_ASYNC; inst->alg.base.cra_priority = (ghash->base.cra_priority + @@ -709,7 +709,6 @@ static int crypto_gcm_create(struct cryp { const char *cipher_name; char ctr_name[CRYPTO_MAX_ALG_NAME]; - char full_name[CRYPTO_MAX_ALG_NAME]; cipher_name = crypto_attr_alg_name(tb[1]); if (IS_ERR(cipher_name)) @@ -719,12 +718,7 @@ static int crypto_gcm_create(struct cryp CRYPTO_MAX_ALG_NAME) return -ENAMETOOLONG; - if (snprintf(full_name, CRYPTO_MAX_ALG_NAME, "gcm(%s)", cipher_name) >= - CRYPTO_MAX_ALG_NAME) - return -ENAMETOOLONG; - - return crypto_gcm_create_common(tmpl, tb, full_name, - ctr_name, "ghash"); + return crypto_gcm_create_common(tmpl, tb, ctr_name, "ghash"); } static struct crypto_template crypto_gcm_tmpl = { @@ -738,7 +732,6 @@ static int crypto_gcm_base_create(struct { const char *ctr_name; const char *ghash_name; - char full_name[CRYPTO_MAX_ALG_NAME]; ctr_name = crypto_attr_alg_name(tb[1]); if (IS_ERR(ctr_name)) @@ -748,12 +741,7 @@ static int crypto_gcm_base_create(struct if (IS_ERR(ghash_name)) return PTR_ERR(ghash_name); - if (snprintf(full_name, CRYPTO_MAX_ALG_NAME, "gcm_base(%s,%s)", - ctr_name, ghash_name) >= CRYPTO_MAX_ALG_NAME) - return -ENAMETOOLONG; - - return crypto_gcm_create_common(tmpl, tb, full_name, - ctr_name, ghash_name); + return crypto_gcm_create_common(tmpl, tb, ctr_name, ghash_name); } static struct crypto_template crypto_gcm_base_tmpl = {