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=-20.2 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_GIT autolearn=unavailable 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 9276BC12002 for ; Mon, 19 Jul 2021 14:58:05 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 809456112D for ; Mon, 19 Jul 2021 14:58:05 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S241844AbhGSORX (ORCPT ); Mon, 19 Jul 2021 10:17:23 -0400 Received: from mail.kernel.org ([198.145.29.99]:50546 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S241676AbhGSORE (ORCPT ); Mon, 19 Jul 2021 10:17:04 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id ED98861002; Mon, 19 Jul 2021 14:57:43 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1626706664; bh=F42cCTH/utOiDjZj6SlUMUviirUJIk8fA4Dqdm1MB4A=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=QsdssozXniTB+VcUpCepi59/Q+KwjMZhvOIglXsuigRGjZ+hqIuDdymq3KVQAFCsP sbtbVdysXqujaW/hTfNU61YOyBcjDo6NB8pH2r6XAUPVRbE9n0wvsOAc016FF9NFlp wG95NgBkEdvCMM4nlSFxFhSK9TnlW+gPKY2qVdhg= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Sami Tolvanen , Eric Biggers , Ard Biesheuvel , Eric Biggers , Herbert Xu , Sasha Levin Subject: [PATCH 4.4 037/188] crypto: shash - avoid comparing pointers to exported functions under CFI Date: Mon, 19 Jul 2021 16:50:21 +0200 Message-Id: <20210719144921.763325847@linuxfoundation.org> X-Mailer: git-send-email 2.32.0 In-Reply-To: <20210719144913.076563739@linuxfoundation.org> References: <20210719144913.076563739@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Ard Biesheuvel [ Upstream commit 22ca9f4aaf431a9413dcc115dd590123307f274f ] crypto_shash_alg_has_setkey() is implemented by testing whether the .setkey() member of a struct shash_alg points to the default version, called shash_no_setkey(). As crypto_shash_alg_has_setkey() is a static inline, this requires shash_no_setkey() to be exported to modules. Unfortunately, when building with CFI, function pointers are routed via CFI stubs which are private to each module (or to the kernel proper) and so this function pointer comparison may fail spuriously. Let's fix this by turning crypto_shash_alg_has_setkey() into an out of line function. Cc: Sami Tolvanen Cc: Eric Biggers Signed-off-by: Ard Biesheuvel Reviewed-by: Eric Biggers Reviewed-by: Sami Tolvanen Signed-off-by: Herbert Xu Signed-off-by: Sasha Levin --- crypto/shash.c | 18 +++++++++++++++--- include/crypto/internal/hash.h | 8 +------- 2 files changed, 16 insertions(+), 10 deletions(-) diff --git a/crypto/shash.c b/crypto/shash.c index 4f89f78031e2..8f162476d214 100644 --- a/crypto/shash.c +++ b/crypto/shash.c @@ -24,12 +24,24 @@ static const struct crypto_type crypto_shash_type; -int shash_no_setkey(struct crypto_shash *tfm, const u8 *key, - unsigned int keylen) +static int shash_no_setkey(struct crypto_shash *tfm, const u8 *key, + unsigned int keylen) { return -ENOSYS; } -EXPORT_SYMBOL_GPL(shash_no_setkey); + +/* + * Check whether an shash algorithm has a setkey function. + * + * For CFI compatibility, this must not be an inline function. This is because + * when CFI is enabled, modules won't get the same address for shash_no_setkey + * (if it were exported, which inlining would require) as the core kernel will. + */ +bool crypto_shash_alg_has_setkey(struct shash_alg *alg) +{ + return alg->setkey != shash_no_setkey; +} +EXPORT_SYMBOL_GPL(crypto_shash_alg_has_setkey); static int shash_setkey_unaligned(struct crypto_shash *tfm, const u8 *key, unsigned int keylen) diff --git a/include/crypto/internal/hash.h b/include/crypto/internal/hash.h index dab9569f22bf..e51741670a60 100644 --- a/include/crypto/internal/hash.h +++ b/include/crypto/internal/hash.h @@ -83,13 +83,7 @@ int ahash_register_instance(struct crypto_template *tmpl, struct ahash_instance *inst); void ahash_free_instance(struct crypto_instance *inst); -int shash_no_setkey(struct crypto_shash *tfm, const u8 *key, - unsigned int keylen); - -static inline bool crypto_shash_alg_has_setkey(struct shash_alg *alg) -{ - return alg->setkey != shash_no_setkey; -} +bool crypto_shash_alg_has_setkey(struct shash_alg *alg); bool crypto_hash_alg_has_setkey(struct hash_alg_common *halg); -- 2.30.2