From patchwork Tue Feb 13 02:13:12 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Gabriel Krisman Bertazi X-Patchwork-Id: 13554398 Received: from smtp-out2.suse.de (smtp-out2.suse.de [195.135.223.131]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id E49914687; Tue, 13 Feb 2024 02:13:38 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=195.135.223.131 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1707790420; cv=none; b=fczHVSC2KYjlXo0wg6kODLs4XGfgY2aVfJrEs7HxkHrWCN9LnO70QTS44oo1IQNgnxiRojBt0dXniG8iThj6tWyTswx/IYYmloIZ3Nu4k+UxqEIHFU9yT7TY/o48xBM0O6hvMfR4aub1NSllqwib8klRG3vSIqnbcs8DINnVQQA= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1707790420; c=relaxed/simple; bh=7+dsiojWXQnyMkcnZ66iDi2GpW5QMmMk/n+bMml/AvI=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=gce20+xlK+wLJ0/L8fCM7E0KY3gO8VGc4zNR6yE1XG0r2PwEObsqIw4VI/2GcHhizlqmUga7aDnCtRmyA/cVGiILFvqI/kmhUgzLPw8+WFUuxJxx2mRtiJDD6r3eX3OFMsB1/g+LdjbZ2SmwSocNXr26gbU7mFWlxkWJOF+mLKk= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=suse.de; spf=pass smtp.mailfrom=suse.de; dkim=pass (1024-bit key) header.d=suse.de header.i=@suse.de header.b=CraUMEH6; dkim=permerror (0-bit key) header.d=suse.de header.i=@suse.de header.b=nBIJYWX3; dkim=pass (1024-bit key) header.d=suse.de header.i=@suse.de header.b=CraUMEH6; dkim=permerror (0-bit key) header.d=suse.de header.i=@suse.de header.b=nBIJYWX3; arc=none smtp.client-ip=195.135.223.131 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=suse.de Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=suse.de Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=suse.de header.i=@suse.de header.b="CraUMEH6"; dkim=permerror (0-bit key) header.d=suse.de header.i=@suse.de header.b="nBIJYWX3"; dkim=pass (1024-bit key) header.d=suse.de header.i=@suse.de header.b="CraUMEH6"; dkim=permerror (0-bit key) header.d=suse.de header.i=@suse.de header.b="nBIJYWX3" Received: from imap1.dmz-prg2.suse.org (imap1.dmz-prg2.suse.org [10.150.64.97]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) by smtp-out2.suse.de (Postfix) with ESMTPS id F3DAF1F79E; Tue, 13 Feb 2024 02:13:36 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_rsa; t=1707790417; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=D59OP2BUYYvV4JTaStIU9zARbS/Uaxo74njoDI27EFI=; b=CraUMEH6+JSJXxxKfYKxIUtWQXjV4gLU+0ryRS54WdfayCSdO4VQPZWxH4/xQkxfoNouuF RUU8yNDI2f3H6d5fz99vs/GEkJ9bdLrigswoTDqF0i8MG6optfOYT+ZTxqICK83qmu4o30 gtOAqvC9MYXbkH1OAzTqBAnYUriRaxk= DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_ed25519; t=1707790417; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=D59OP2BUYYvV4JTaStIU9zARbS/Uaxo74njoDI27EFI=; b=nBIJYWX3zz4DqX2iFnYIpnXt80NZW/eJsUPkpQk4yTOCdJWqJh0iBFwMaXuo/WD+q+i3x6 NOaE2gXbY7Mp2vBA== DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_rsa; t=1707790417; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=D59OP2BUYYvV4JTaStIU9zARbS/Uaxo74njoDI27EFI=; b=CraUMEH6+JSJXxxKfYKxIUtWQXjV4gLU+0ryRS54WdfayCSdO4VQPZWxH4/xQkxfoNouuF RUU8yNDI2f3H6d5fz99vs/GEkJ9bdLrigswoTDqF0i8MG6optfOYT+ZTxqICK83qmu4o30 gtOAqvC9MYXbkH1OAzTqBAnYUriRaxk= DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_ed25519; t=1707790417; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=D59OP2BUYYvV4JTaStIU9zARbS/Uaxo74njoDI27EFI=; b=nBIJYWX3zz4DqX2iFnYIpnXt80NZW/eJsUPkpQk4yTOCdJWqJh0iBFwMaXuo/WD+q+i3x6 NOaE2gXbY7Mp2vBA== Received: from imap1.dmz-prg2.suse.org (localhost [127.0.0.1]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) by imap1.dmz-prg2.suse.org (Postfix) with ESMTPS id BA60F13A4B; Tue, 13 Feb 2024 02:13:36 +0000 (UTC) Received: from dovecot-director2.suse.de ([2a07:de40:b281:106:10:150:64:167]) by imap1.dmz-prg2.suse.org with ESMTPSA id TLReJ1DQymUQeAAAD6G6ig (envelope-from ); Tue, 13 Feb 2024 02:13:36 +0000 From: Gabriel Krisman Bertazi To: ebiggers@kernel.org, viro@zeniv.linux.org.uk Cc: jaegeuk@kernel.org, tytso@mit.edu, amir73il@gmail.com, linux-ext4@vger.kernel.org, linux-f2fs-devel@lists.sourceforge.net, linux-fsdevel@vger.kernel.org, brauner@kernel.org, Gabriel Krisman Bertazi Subject: [PATCH v6 01/10] ovl: Always reject mounting over case-insensitive directories Date: Mon, 12 Feb 2024 21:13:12 -0500 Message-ID: <20240213021321.1804-2-krisman@suse.de> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20240213021321.1804-1-krisman@suse.de> References: <20240213021321.1804-1-krisman@suse.de> Precedence: bulk X-Mailing-List: linux-fsdevel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Authentication-Results: smtp-out2.suse.de; none X-Spamd-Result: default: False [1.90 / 50.00]; ARC_NA(0.00)[]; RCVD_VIA_SMTP_AUTH(0.00)[]; FROM_HAS_DN(0.00)[]; TO_DN_SOME(0.00)[]; FREEMAIL_ENVRCPT(0.00)[gmail.com]; R_MISSING_CHARSET(2.50)[]; MIME_GOOD(-0.10)[text/plain]; TO_MATCH_ENVRCPT_ALL(0.00)[]; BROKEN_CONTENT_TYPE(1.50)[]; RCVD_COUNT_THREE(0.00)[3]; DKIM_SIGNED(0.00)[suse.de:s=susede2_rsa,suse.de:s=susede2_ed25519]; RCPT_COUNT_SEVEN(0.00)[10]; MID_CONTAINS_FROM(1.00)[]; DBL_BLOCKED_OPENRESOLVER(0.00)[suse.de:email]; FUZZY_BLOCKED(0.00)[rspamd.com]; FROM_EQ_ENVFROM(0.00)[]; MIME_TRACE(0.00)[0:+]; FREEMAIL_CC(0.00)[kernel.org,mit.edu,gmail.com,vger.kernel.org,lists.sourceforge.net,suse.de]; RCVD_TLS_ALL(0.00)[]; BAYES_HAM(-3.00)[100.00%] X-Spam-Level: * X-Spam-Score: 1.90 X-Spam-Flag: NO overlayfs relies on the filesystem setting DCACHE_OP_HASH or DCACHE_OP_COMPARE to reject mounting over case-insensitive directories. Since commit bb9cd9106b22 ("fscrypt: Have filesystems handle their d_ops"), we set ->d_op through a hook in ->d_lookup, which means the root dentry won't have them, causing the mount to accidentally succeed. In v6.7-rc7, the following sequence will succeed to mount, but any dentry other than the root dentry will be a "weird" dentry to ovl and fail with EREMOTE. mkfs.ext4 -O casefold lower.img mount -O loop lower.img lower mount -t overlay -o lowerdir=lower,upperdir=upper,workdir=work ovl /mnt Mounting on a subdirectory fails, as expected, because DCACHE_OP_HASH and DCACHE_OP_COMPARE are properly set by ->lookup. Fix by explicitly rejecting superblocks that allow case-insensitive dentries. Yes, this will be solved when we move d_op configuration back to ->s_d_op. Yet, we better have an explicit fix to avoid messing up again. While there, re-sort the entries to have more descriptive error messages first. Fixes: bb9cd9106b22 ("fscrypt: Have filesystems handle their d_ops") Signed-off-by: Gabriel Krisman Bertazi Acked-by: Amir Goldstein --- changes since v5: - summary line again (eric) changes since v3: - Case insensitive filesystem ->Case insensitive capable filesystem (eric) - clarify patch summary line changes since v2: - Re-sort checks to trigger more descriptive error messages first (Amir) - Add code comment (Amir) --- fs/overlayfs/params.c | 14 +++++++++++--- include/linux/fs.h | 9 +++++++++ 2 files changed, 20 insertions(+), 3 deletions(-) diff --git a/fs/overlayfs/params.c b/fs/overlayfs/params.c index 3fe2dde1598f..488f920f79d2 100644 --- a/fs/overlayfs/params.c +++ b/fs/overlayfs/params.c @@ -280,12 +280,20 @@ static int ovl_mount_dir_check(struct fs_context *fc, const struct path *path, { struct ovl_fs_context *ctx = fc->fs_private; - if (ovl_dentry_weird(path->dentry)) - return invalfc(fc, "filesystem on %s not supported", name); - if (!d_is_dir(path->dentry)) return invalfc(fc, "%s is not a directory", name); + /* + * Root dentries of case-insensitive capable filesystems might + * not have the dentry operations set, but still be incompatible + * with overlayfs. Check explicitly to prevent post-mount + * failures. + */ + if (sb_has_encoding(path->mnt->mnt_sb)) + return invalfc(fc, "case-insensitive capable filesystem on %s not supported", name); + + if (ovl_dentry_weird(path->dentry)) + return invalfc(fc, "filesystem on %s not supported", name); /* * Check whether upper path is read-only here to report failures diff --git a/include/linux/fs.h b/include/linux/fs.h index 98b7a7a8c42e..e6667ece5e64 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -3203,6 +3203,15 @@ extern int generic_check_addressable(unsigned, u64); extern void generic_set_encrypted_ci_d_ops(struct dentry *dentry); +static inline bool sb_has_encoding(const struct super_block *sb) +{ +#if IS_ENABLED(CONFIG_UNICODE) + return !!sb->s_encoding; +#else + return false; +#endif +} + int may_setattr(struct mnt_idmap *idmap, struct inode *inode, unsigned int ia_valid); int setattr_prepare(struct mnt_idmap *, struct dentry *, struct iattr *);