linux-ext4 - [PATCH v5 02/10] ecryptfs: Reject casefold directory inodes

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <20230812004146.30980-3-krisman@suse.de>
Date:   Fri, 11 Aug 2023 20:41:38 -0400
From:   Gabriel Krisman Bertazi <krisman@...e.de>
To:     viro@...iv.linux.org.uk, brauner@...nel.org, tytso@....edu,
        ebiggers@...nel.org, jaegeuk@...nel.org
Cc:     linux-fsdevel@...r.kernel.org, linux-ext4@...r.kernel.org,
        linux-f2fs-devel@...ts.sourceforge.net,
        Gabriel Krisman Bertazi <krisman@...e.de>
Subject: [PATCH v5 02/10] ecryptfs: Reject casefold directory inodes

Even though it seems to be able to resolve some names of
case-insensitive directories, the lack of d_hash and d_compare means we
end up with a broken state in the d_cache.  Considering it was never a
goal to support these two together, and we are preparing to use
d_revalidate in case-insensitive filesystems, which would make the
combination even more broken, reject any attempt to get a casefolded
inode from ecryptfs.

Signed-off-by: Gabriel Krisman Bertazi <krisman@...e.de>
---
 fs/ecryptfs/inode.c | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/fs/ecryptfs/inode.c b/fs/ecryptfs/inode.c
index 83274915ba6d..1305dc49df78 100644
--- a/fs/ecryptfs/inode.c
+++ b/fs/ecryptfs/inode.c
@@ -78,6 +78,14 @@ static struct inode *__ecryptfs_get_inode(struct inode *lower_inode,
 
 	if (lower_inode->i_sb != ecryptfs_superblock_to_lower(sb))
 		return ERR_PTR(-EXDEV);
+
+	/* Reject dealing with casefold directories. */
+	if (S_ISDIR(lower_inode->i_mode) && dir_is_casefolded(lower_inode)) {
+		pr_err_ratelimited("%s: Can't handle casefolded directory.\n",
+				   __func__);
+		return ERR_PTR(-EREMOTE);
+	}
+
 	if (!igrab(lower_inode))
 		return ERR_PTR(-ESTALE);
 	inode = iget5_locked(sb, (unsigned long)lower_inode,
-- 
2.41.0