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=-13.1 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS 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 E97BFC43461 for ; Thu, 17 Sep 2020 13:07:35 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id A64CF2083B for ; Thu, 17 Sep 2020 13:07:35 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1600348055; bh=olPA59AHeALmdazeYKWfpYsBo4J0J6ZWIIQE72g2Yac=; h=Subject:From:To:Cc:Date:In-Reply-To:References:List-ID:From; b=zplccPPXIuRUTAJiDAjRRVslyUCoGpNLgs+oZk9MlsMuCYj9XiQViNMZgv+GT5wcN xzfnPhYpBmr95KMUIYTSBm+vQzLfNhSLk0XOOka6DOj9KIGvwzMSK5JPdqYZTT5kat GvCigA/sGZ6SqBlH6wZfbpKupUBf7rOS5svuhV1s= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727062AbgIQNHa (ORCPT ); Thu, 17 Sep 2020 09:07:30 -0400 Received: from mail.kernel.org ([198.145.29.99]:51554 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726765AbgIQMc5 (ORCPT ); Thu, 17 Sep 2020 08:32:57 -0400 Received: from tleilax.poochiereds.net (68-20-15-154.lightspeed.rlghnc.sbcglobal.net [68.20.15.154]) (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 E03D02087D; Thu, 17 Sep 2020 12:32:40 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1600345961; bh=olPA59AHeALmdazeYKWfpYsBo4J0J6ZWIIQE72g2Yac=; h=Subject:From:To:Cc:Date:In-Reply-To:References:From; b=QBsfQLFvyNNo7AazxeBdsvgrBNu/5E0ANikO/MgA+2DaZ8Hy+kVN+DnzTkA331w9R F99L+XLGUhz5QfB0i3mLuEVhal68EbIHv3IyFk1bRT/k04PDMksWsrW9xN8pUPc555 8JmVCKQIahp87c2ulFoeqvulKpTDYSeXTHOvjuQc= Message-ID: <41ad3cd50f4d213455bef4e7c42143c289690222.camel@kernel.org> Subject: Re: [PATCH v3 13/13] fscrypt: make fscrypt_set_test_dummy_encryption() take a 'const char *' From: Jeff Layton To: Eric Biggers , linux-fscrypt@vger.kernel.org Cc: linux-ext4@vger.kernel.org, linux-f2fs-devel@lists.sourceforge.net, linux-mtd@lists.infradead.org, ceph-devel@vger.kernel.org, Daniel Rosenberg Date: Thu, 17 Sep 2020 08:32:39 -0400 In-Reply-To: <20200917041136.178600-14-ebiggers@kernel.org> References: <20200917041136.178600-1-ebiggers@kernel.org> <20200917041136.178600-14-ebiggers@kernel.org> Content-Type: text/plain; charset="UTF-8" User-Agent: Evolution 3.36.5 (3.36.5-1.fc32) MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-ext4@vger.kernel.org On Wed, 2020-09-16 at 21:11 -0700, Eric Biggers wrote: > From: Eric Biggers > > fscrypt_set_test_dummy_encryption() requires that the optional argument > to the test_dummy_encryption mount option be specified as a substring_t. > That doesn't work well with filesystems that use the new mount API, > since the new way of parsing mount options doesn't use substring_t. > > Make it take the argument as a 'const char *' instead. > > Instead of moving the match_strdup() into the callers in ext4 and f2fs, > make them just use arg->from directly. Since the pattern is > "test_dummy_encryption=%s", the argument will be null-terminated. > Are you sure about that? I thought the point of substring_t was to give you a token from the string without null terminating it. ISTM that when you just pass in ->from, you might end up with trailing arguments in your string like this. e.g.: "v2,foo,bar,baz" ...and then that might fail to match properly in fscrypt_set_test_dummy_encryption. > Signed-off-by: Eric Biggers > --- > fs/crypto/policy.c | 20 ++++++-------------- > fs/ext4/super.c | 2 +- > fs/f2fs/super.c | 2 +- > include/linux/fscrypt.h | 5 +---- > 4 files changed, 9 insertions(+), 20 deletions(-) > > diff --git a/fs/crypto/policy.c b/fs/crypto/policy.c > index 97cf07543651f..4441d9944b9ef 100644 > --- a/fs/crypto/policy.c > +++ b/fs/crypto/policy.c > @@ -697,8 +697,7 @@ EXPORT_SYMBOL_GPL(fscrypt_set_context); > /** > * fscrypt_set_test_dummy_encryption() - handle '-o test_dummy_encryption' > * @sb: the filesystem on which test_dummy_encryption is being specified > - * @arg: the argument to the test_dummy_encryption option. > - * If no argument was specified, then @arg->from == NULL. > + * @arg: the argument to the test_dummy_encryption option. May be NULL. > * @dummy_policy: the filesystem's current dummy policy (input/output, see > * below) > * > @@ -712,29 +711,23 @@ EXPORT_SYMBOL_GPL(fscrypt_set_context); > * -EEXIST if a different dummy policy is already set; > * or another -errno value. > */ > -int fscrypt_set_test_dummy_encryption(struct super_block *sb, > - const substring_t *arg, > +int fscrypt_set_test_dummy_encryption(struct super_block *sb, const char *arg, > struct fscrypt_dummy_policy *dummy_policy) > { > - const char *argstr = "v2"; > - const char *argstr_to_free = NULL; > struct fscrypt_key_specifier key_spec = { 0 }; > int version; > union fscrypt_policy *policy = NULL; > int err; > > - if (arg->from) { > - argstr = argstr_to_free = match_strdup(arg); > - if (!argstr) > - return -ENOMEM; > - } > + if (!arg) > + arg = "v2"; > > - if (!strcmp(argstr, "v1")) { > + if (!strcmp(arg, "v1")) { > version = FSCRYPT_POLICY_V1; > key_spec.type = FSCRYPT_KEY_SPEC_TYPE_DESCRIPTOR; > memset(key_spec.u.descriptor, 0x42, > FSCRYPT_KEY_DESCRIPTOR_SIZE); > - } else if (!strcmp(argstr, "v2")) { > + } else if (!strcmp(arg, "v2")) { > version = FSCRYPT_POLICY_V2; > key_spec.type = FSCRYPT_KEY_SPEC_TYPE_IDENTIFIER; > /* key_spec.u.identifier gets filled in when adding the key */ > @@ -785,7 +778,6 @@ int fscrypt_set_test_dummy_encryption(struct super_block *sb, > err = 0; > out: > kfree(policy); > - kfree(argstr_to_free); > return err; > } > EXPORT_SYMBOL_GPL(fscrypt_set_test_dummy_encryption); > diff --git a/fs/ext4/super.c b/fs/ext4/super.c > index 7e77722406e2f..ed5624285a475 100644 > --- a/fs/ext4/super.c > +++ b/fs/ext4/super.c > @@ -1893,7 +1893,7 @@ static int ext4_set_test_dummy_encryption(struct super_block *sb, > "Can't set test_dummy_encryption on remount"); > return -1; > } > - err = fscrypt_set_test_dummy_encryption(sb, arg, > + err = fscrypt_set_test_dummy_encryption(sb, arg->from, > &sbi->s_dummy_enc_policy); > if (err) { > if (err == -EEXIST) > diff --git a/fs/f2fs/super.c b/fs/f2fs/super.c > index f2b3d1a279fb7..c72d22c0c52e7 100644 > --- a/fs/f2fs/super.c > +++ b/fs/f2fs/super.c > @@ -438,7 +438,7 @@ static int f2fs_set_test_dummy_encryption(struct super_block *sb, > return -EINVAL; > } > err = fscrypt_set_test_dummy_encryption( > - sb, arg, &F2FS_OPTION(sbi).dummy_enc_policy); > + sb, arg->from, &F2FS_OPTION(sbi).dummy_enc_policy); > if (err) { > if (err == -EEXIST) > f2fs_warn(sbi, > diff --git a/include/linux/fscrypt.h b/include/linux/fscrypt.h > index b3b0c5675c6b1..fc67c4cbaa968 100644 > --- a/include/linux/fscrypt.h > +++ b/include/linux/fscrypt.h > @@ -15,7 +15,6 @@ > > #include > #include > -#include > #include > #include > > @@ -153,9 +152,7 @@ struct fscrypt_dummy_policy { > const union fscrypt_policy *policy; > }; > > -int fscrypt_set_test_dummy_encryption( > - struct super_block *sb, > - const substring_t *arg, > +int fscrypt_set_test_dummy_encryption(struct super_block *sb, const char *arg, > struct fscrypt_dummy_policy *dummy_policy); > void fscrypt_show_test_dummy_encryption(struct seq_file *seq, char sep, > struct super_block *sb); -- Jeff Layton