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=-16.2 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 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 9D855C48BD1 for ; Thu, 10 Jun 2021 18:48:07 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 7D924613B0 for ; Thu, 10 Jun 2021 18:48:07 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230080AbhFJSuD (ORCPT ); Thu, 10 Jun 2021 14:50:03 -0400 Received: from mail.kernel.org ([198.145.29.99]:46426 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229935AbhFJSuC (ORCPT ); Thu, 10 Jun 2021 14:50:02 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 3C657613DF; Thu, 10 Jun 2021 18:48:06 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1623350886; bh=V7TG4y7UNJ3EHwuNTUY6ZTRf2X1MD+YMR1lY0uWspXo=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=OGptpNtxHYLF7t6tCrjkhrpLMK9PDbecotaG7d1VeTacWqsnxqF78YCwbZ2IFVfum zDq+tAeEKzht5wSS/eePTC9zzrhAW+dBxiM+XgdfyLU9RJqT9a/wpb9pHfWKyr8/XU I6Fc9NoFaYdG7JAmLR2N/Ud9lHwuShAIpVTMxlgvvzuJPfFudmL0Eks4kBVWe0XBYw kezjFCpaZgrH1bmjpuOsrWZWdROELmfFUnj8maPQKqvwNEq7FZpTOPH3BCH1o+V9oj VwZcfiezhOmWTXaARYZjkpE33HhZtbSEdmmdWX/ybddE16YO0zlepo5JfA8gMqiUqG 4FEfrKS0lSYPQ== Date: Thu, 10 Jun 2021 11:48:04 -0700 From: Eric Biggers To: Ard Biesheuvel Cc: linux-crypto@vger.kernel.org, herbert@gondor.apana.org.au, Sami Tolvanen Subject: Re: [PATCH v3] crypto: shash - avoid comparing pointers to exported functions under CFI Message-ID: References: <20210610062150.212779-1-ardb@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20210610062150.212779-1-ardb@kernel.org> Precedence: bulk List-ID: X-Mailing-List: linux-crypto@vger.kernel.org On Thu, Jun 10, 2021 at 08:21:50AM +0200, Ard Biesheuvel wrote: > 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 > --- > v3: improve comment as per Eric's suggestion > v2: add code comment to explain why the function needs to remain out of > line > > crypto/shash.c | 18 +++++++++++++++--- > include/crypto/internal/hash.h | 8 +------- > 2 files changed, 16 insertions(+), 10 deletions(-) > Reviewed-by: Eric Biggers