From patchwork Fri Jan 19 18:47:33 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: 13524102 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 lists.sourceforge.net (lists.sourceforge.net [216.105.38.7]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id AA8F1C47DD3 for ; Fri, 19 Jan 2024 18:48:14 +0000 (UTC) Received: from [127.0.0.1] (helo=sfs-ml-2.v29.lw.sourceforge.com) by sfs-ml-2.v29.lw.sourceforge.com with esmtp (Exim 4.95) (envelope-from ) id 1rQtuX-0000Kk-Ba; Fri, 19 Jan 2024 18:48:13 +0000 Received: from [172.30.20.202] (helo=mx.sourceforge.net) by sfs-ml-2.v29.lw.sourceforge.com with esmtps (TLS1.2) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.95) (envelope-from ) id 1rQtuU-0000Kb-Ie for linux-f2fs-devel@lists.sourceforge.net; Fri, 19 Jan 2024 18:48:10 +0000 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=sourceforge.net; s=x; h=Content-Transfer-Encoding:MIME-Version:References: In-Reply-To:Message-ID:Date:Subject:Cc:To:From:Sender:Reply-To:Content-Type: Content-ID:Content-Description:Resent-Date:Resent-From:Resent-Sender: Resent-To:Resent-Cc:Resent-Message-ID:List-Id:List-Help:List-Unsubscribe: List-Subscribe:List-Post:List-Owner:List-Archive; bh=noWIkV7tDOxT+ahoicDZr82jxDDniPzXUm/ClBuwL34=; b=JnmX+K4T0sygB934ISj8vdczHr FUlXBFXYQBcQvcjYEzE1WA5DHg/cp0EtzHR5bEm0d4NyWJlrkiupUOh1e6OEGNoCScqxJOKQYnEkp Mn2nsjObK9aInt0xZDuo0s+uhrxyIFoIb8m5xhXYFdXk00qRzgKJ8UgiETgzof0utk7c=; DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=sf.net; s=x ; h=Content-Transfer-Encoding:MIME-Version:References:In-Reply-To:Message-ID: Date:Subject:Cc:To:From:Sender:Reply-To:Content-Type:Content-ID: Content-Description:Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc :Resent-Message-ID:List-Id:List-Help:List-Unsubscribe:List-Subscribe: List-Post:List-Owner:List-Archive; bh=noWIkV7tDOxT+ahoicDZr82jxDDniPzXUm/ClBuwL34=; b=AhT5asZT5wD4zAFIZSgCfcnmYq srdA6IPivfzFxMyhKcsiOFHsrum22jPzm/IXmAN7aXgeuZ3HFK8qvFROs9eUJlwlMNEvk9efGxtH+ RyZfWAZFujLL/6ALNqLOE6BRE7WRZSJrLnm6+B6+JEyRJIH3DggKmHS+lU/3uacMk8Ag=; Received: from smtp-out2.suse.de ([195.135.223.131]) by sfi-mx-2.v28.lw.sourceforge.com with esmtps (TLS1.2:ECDHE-RSA-AES128-GCM-SHA256:128) (Exim 4.95) id 1rQtuQ-0001aE-2h for linux-f2fs-devel@lists.sourceforge.net; Fri, 19 Jan 2024 18:48:10 +0000 Received: from imap1.dmz-prg2.suse.org (imap1.dmz-prg2.suse.org [IPv6:2a07:de40:b281:104:10:150:64:97]) (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 11E241F809; Fri, 19 Jan 2024 18:47:55 +0000 (UTC) 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 92474136F5; Fri, 19 Jan 2024 18:47:54 +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 YGWeEdrDqmU8DAAAD6G6ig (envelope-from ); Fri, 19 Jan 2024 18:47:54 +0000 From: Gabriel Krisman Bertazi To: viro@zeniv.linux.org.uk, ebiggers@kernel.org, jaegeuk@kernel.org, tytso@mit.edu Date: Fri, 19 Jan 2024 15:47:33 -0300 Message-ID: <20240119184742.31088-2-krisman@suse.de> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20240119184742.31088-1-krisman@suse.de> References: <20240119184742.31088-1-krisman@suse.de> MIME-Version: 1.0 Authentication-Results: smtp-out2.suse.de; none X-Rspamd-Server: rspamd2.dmz-prg2.suse.org X-Spamd-Result: default: False [-4.00 / 50.00]; REPLY(-4.00)[] X-Rspamd-Queue-Id: 11E241F809 X-Headers-End: 1rQtuQ-0001aE-2h Subject: [f2fs-dev] [PATCH v3 01/10] ovl: Reject mounting case-insensitive filesystems X-BeenThere: linux-f2fs-devel@lists.sourceforge.net X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: linux-fsdevel@vger.kernel.org, Gabriel Krisman Bertazi , linux-ext4@vger.kernel.org, amir73il@gmail.com, linux-f2fs-devel@lists.sourceforge.net Errors-To: linux-f2fs-devel-bounces@lists.sourceforge.net 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. 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 v2: - Re-sort checks to trigger more descriptive error messages first (Amir) - Add code comment (Amir) --- fs/overlayfs/params.c | 13 ++++++++++--- include/linux/fs.h | 9 +++++++++ 2 files changed, 19 insertions(+), 3 deletions(-) diff --git a/fs/overlayfs/params.c b/fs/overlayfs/params.c index 3fe2dde1598f..09a4973f26f9 100644 --- a/fs/overlayfs/params.c +++ b/fs/overlayfs/params.c @@ -280,12 +280,19 @@ 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 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 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 *);