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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id DD177CCA48A for ; Tue, 7 Jun 2022 21:36:35 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1380685AbiFGVft (ORCPT ); Tue, 7 Jun 2022 17:35:49 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:57294 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1377233AbiFGUlq (ORCPT ); Tue, 7 Jun 2022 16:41:46 -0400 Received: from sin.source.kernel.org (sin.source.kernel.org [145.40.73.55]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 159B81F0A68; Tue, 7 Jun 2022 11:38:39 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by sin.source.kernel.org (Postfix) with ESMTPS id 29F62CE21CD; Tue, 7 Jun 2022 18:38:13 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 31D7AC385A2; Tue, 7 Jun 2022 18:38:11 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1654627091; bh=et0y1Nwx774A1CZnOPcGrx2xvsQFprJZsgw+6HiBkW8=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=digazspN0nklm8mgZ9+TRFj0Fy3DJipmEhIvsNHiuUwZ2goTRseNxAwLGz2qPYMWU D6dctoVF8q+PWOKlsFVcVzHJ9+ORQsONt9h9YBqrEvd3uzthIxjz6AnsI15Lw+Cw0b YPjjxfyGPXEZewmP1dawmK9PhNfE+AFUjHmTBhj8= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Eric Biggers , Gabriel Krisman Bertazi , Jaegeuk Kim Subject: [PATCH 5.17 615/772] f2fs: dont use casefolded comparison for "." and ".." Date: Tue, 7 Jun 2022 19:03:27 +0200 Message-Id: <20220607165007.060610005@linuxfoundation.org> X-Mailer: git-send-email 2.36.1 In-Reply-To: <20220607164948.980838585@linuxfoundation.org> References: <20220607164948.980838585@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: Eric Biggers commit b5639bb4313b9d455fc9fc4768d23a5e4ca8cb9d upstream. Tryng to rename a directory that has all following properties fails with EINVAL and triggers the 'WARN_ON_ONCE(!fscrypt_has_encryption_key(dir))' in f2fs_match_ci_name(): - The directory is casefolded - The directory is encrypted - The directory's encryption key is not yet set up - The parent directory is *not* encrypted The problem is incorrect handling of the lookup of ".." to get the parent reference to update. fscrypt_setup_filename() treats ".." (and ".") specially, as it's never encrypted. It's passed through as-is, and setting up the directory's key is not attempted. As the name isn't a no-key name, f2fs treats it as a "normal" name and attempts a casefolded comparison. That breaks the assumption of the WARN_ON_ONCE() in f2fs_match_ci_name() which assumes that for encrypted directories, casefolded comparisons only happen when the directory's key is set up. We could just remove this WARN_ON_ONCE(). However, since casefolding is always a no-op on "." and ".." anyway, let's instead just not casefold these names. This results in the standard bytewise comparison. Fixes: 7ad08a58bf67 ("f2fs: Handle casefolding with Encryption") Cc: # v5.11+ Signed-off-by: Eric Biggers Reviewed-by: Gabriel Krisman Bertazi Signed-off-by: Jaegeuk Kim Signed-off-by: Greg Kroah-Hartman --- fs/f2fs/dir.c | 3 ++- fs/f2fs/f2fs.h | 10 +++++----- fs/f2fs/hash.c | 11 ++++++----- 3 files changed, 13 insertions(+), 11 deletions(-) --- a/fs/f2fs/dir.c +++ b/fs/f2fs/dir.c @@ -82,7 +82,8 @@ int f2fs_init_casefolded_name(const stru #if IS_ENABLED(CONFIG_UNICODE) struct super_block *sb = dir->i_sb; - if (IS_CASEFOLDED(dir)) { + if (IS_CASEFOLDED(dir) && + !is_dot_dotdot(fname->usr_fname->name, fname->usr_fname->len)) { fname->cf_name.name = f2fs_kmem_cache_alloc(f2fs_cf_name_slab, GFP_NOFS, false, F2FS_SB(sb)); if (!fname->cf_name.name) --- a/fs/f2fs/f2fs.h +++ b/fs/f2fs/f2fs.h @@ -491,11 +491,11 @@ struct f2fs_filename { #if IS_ENABLED(CONFIG_UNICODE) /* * For casefolded directories: the casefolded name, but it's left NULL - * if the original name is not valid Unicode, if the directory is both - * casefolded and encrypted and its encryption key is unavailable, or if - * the filesystem is doing an internal operation where usr_fname is also - * NULL. In all these cases we fall back to treating the name as an - * opaque byte sequence. + * if the original name is not valid Unicode, if the original name is + * "." or "..", if the directory is both casefolded and encrypted and + * its encryption key is unavailable, or if the filesystem is doing an + * internal operation where usr_fname is also NULL. In all these cases + * we fall back to treating the name as an opaque byte sequence. */ struct fscrypt_str cf_name; #endif --- a/fs/f2fs/hash.c +++ b/fs/f2fs/hash.c @@ -91,7 +91,7 @@ static u32 TEA_hash_name(const u8 *p, si /* * Compute @fname->hash. For all directories, @fname->disk_name must be set. * For casefolded directories, @fname->usr_fname must be set, and also - * @fname->cf_name if the filename is valid Unicode. + * @fname->cf_name if the filename is valid Unicode and is not "." or "..". */ void f2fs_hash_filename(const struct inode *dir, struct f2fs_filename *fname) { @@ -110,10 +110,11 @@ void f2fs_hash_filename(const struct ino /* * If the casefolded name is provided, hash it instead of the * on-disk name. If the casefolded name is *not* provided, that - * should only be because the name wasn't valid Unicode, so fall - * back to treating the name as an opaque byte sequence. Note - * that to handle encrypted directories, the fallback must use - * usr_fname (plaintext) rather than disk_name (ciphertext). + * should only be because the name wasn't valid Unicode or was + * "." or "..", so fall back to treating the name as an opaque + * byte sequence. Note that to handle encrypted directories, + * the fallback must use usr_fname (plaintext) rather than + * disk_name (ciphertext). */ WARN_ON_ONCE(!fname->usr_fname->name); if (fname->cf_name.name) {