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=-6.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FSL_HELO_FAKE,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 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 A42C4C2D0C2 for ; Fri, 3 Jan 2020 16:58:16 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 6C36A206DB for ; Fri, 3 Jan 2020 16:58:16 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1578070696; bh=YOjAfPhT0RplAxeR04xru2egqefA61SRCIkmZZ6DL5A=; h=Date:From:To:Subject:References:In-Reply-To:List-ID:From; b=mnz5HzgOkkX+lBWkCHyYrQrugevPFjXDgA/UhHu5QqW7kpZrqq9mNuHZ25XAaiqZ9 S+fs2qFsOVPeLy7RJnG98XpNvXo65iYhT83rDdduYlsiH1ebGHLvYnRkKuMT8jtOWE Cb8z9jikRJIIBZ8BfJEwehaKjxnwUBNHp/qHj2oI= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727994AbgACQ6Q (ORCPT ); Fri, 3 Jan 2020 11:58:16 -0500 Received: from mail.kernel.org ([198.145.29.99]:51928 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727969AbgACQ6Q (ORCPT ); Fri, 3 Jan 2020 11:58:16 -0500 Received: from gmail.com (unknown [104.132.1.77]) (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 637B2206DB for ; Fri, 3 Jan 2020 16:58:15 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1578070695; bh=YOjAfPhT0RplAxeR04xru2egqefA61SRCIkmZZ6DL5A=; h=Date:From:To:Subject:References:In-Reply-To:From; b=PtFbi3CEJtQn4qSa7ma1La2Ut1rpDnlk3EElO9UlWoDhjF/y+hJfZ1azZ1goKir0Q wRvyK1+rhG/6mtewT9aJoxk7JEPlW/HMU49GvH9rxewijjyM2BpAMonNUJCHMRlxvD Z5D58uMwnSQh6L6P7zf2ENCcIpkcrrn3oiNMiu1g= Date: Fri, 3 Jan 2020 08:58:14 -0800 From: Eric Biggers To: linux-fscrypt@vger.kernel.org Subject: Re: [PATCH] fscrypt: verify that the crypto_skcipher has the correct ivsize Message-ID: <20200103165813.GD19521@gmail.com> References: <20191209203918.225691-1-ebiggers@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20191209203918.225691-1-ebiggers@kernel.org> User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-fscrypt-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-fscrypt@vger.kernel.org On Mon, Dec 09, 2019 at 12:39:18PM -0800, Eric Biggers wrote: > From: Eric Biggers > > As a sanity check, verify that the allocated crypto_skcipher actually > has the ivsize that fscrypt is assuming it has. This will always be the > case unless there's a bug. But if there ever is such a bug (e.g. like > there was in earlier versions of the ESSIV conversion patch [1]) it's > preferable for it to be immediately obvious, and not rely on the > ciphertext verification tests failing due to uninitialized IV bytes. > > [1] https://lkml.kernel.org/linux-crypto/20190702215517.GA69157@gmail.com/ > > Signed-off-by: Eric Biggers > --- > fs/crypto/keysetup.c | 4 ++++ > 1 file changed, 4 insertions(+) > > diff --git a/fs/crypto/keysetup.c b/fs/crypto/keysetup.c > index c9f4fe955971f..39fdea79e912f 100644 > --- a/fs/crypto/keysetup.c > +++ b/fs/crypto/keysetup.c > @@ -91,6 +91,10 @@ struct crypto_skcipher *fscrypt_allocate_skcipher(struct fscrypt_mode *mode, > pr_info("fscrypt: %s using implementation \"%s\"\n", > mode->friendly_name, crypto_skcipher_driver_name(tfm)); > } > + if (WARN_ON(crypto_skcipher_ivsize(tfm) != mode->ivsize)) { > + err = -EINVAL; > + goto err_free_tfm; > + } > crypto_skcipher_set_flags(tfm, CRYPTO_TFM_REQ_FORBID_WEAK_KEYS); > err = crypto_skcipher_setkey(tfm, raw_key, mode->keysize); > if (err) > -- > 2.24.0.393.g34dc348eaf-goog > Applied to fscrypt.git#master for 5.6. - Eric