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=-20.4 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,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 0EB0BC07E9A for ; Sun, 4 Jul 2021 23:23:18 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id E185761364 for ; Sun, 4 Jul 2021 23:23:17 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234932AbhGDXZL (ORCPT ); Sun, 4 Jul 2021 19:25:11 -0400 Received: from mail.kernel.org ([198.145.29.99]:56966 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234542AbhGDXPN (ORCPT ); Sun, 4 Jul 2021 19:15:13 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 81445611ED; Sun, 4 Jul 2021 23:12:36 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1625440357; bh=F42cCTH/utOiDjZj6SlUMUviirUJIk8fA4Dqdm1MB4A=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=AXI16QixEICaICtD4nBTxx6o9agtwnOVLzqe1uRHpqMSjLcoczunDa0J9FZHQ1bWp 7Qbk2VAlAhssU5w4EL3vDi/oeXE1wWFoZvhM1DUVyXLQOHwzhbwUYyjsshNWIc3wDA 8XnVxoOHtEEq+CPqW0JgRH6S8QBT81Z7l7sm0RGKdMaHLMQlEkt/X6HkJX6auRQzps 7CieNUapgtFiCnlnourZRLWoSe/O1UQ/H/n/uu6DvkwP5gW7fKj9HCqDNkoijH31KU ghbZSk4qQT3VDxwfHGsrIg27sIvJHoeBelPfMvp4OVlTeO9NYib+lD/l/xlvIneEBg S46lzdn87Q7Yg== From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Ard Biesheuvel , Sami Tolvanen , Eric Biggers , Eric Biggers , Herbert Xu , Sasha Levin , linux-crypto@vger.kernel.org Subject: [PATCH AUTOSEL 4.4 11/15] crypto: shash - avoid comparing pointers to exported functions under CFI Date: Sun, 4 Jul 2021 19:12:17 -0400 Message-Id: <20210704231222.1492037-11-sashal@kernel.org> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20210704231222.1492037-1-sashal@kernel.org> References: <20210704231222.1492037-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore 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