fscrypt: fix renaming and linking special files
authorEric Biggers <ebiggers@google.com>
Mon, 19 Dec 2016 22:20:13 +0000 (14:20 -0800)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Wed, 22 Mar 2017 11:04:18 +0000 (12:04 +0100)
commit 42d97eb0ade31e1bc537d086842f5d6e766d9d51 upstream.

Attempting to link a device node, named pipe, or socket file into an
encrypted directory through rename(2) or link(2) always failed with
EPERM.  This happened because fscrypt_has_permitted_context() saw that
the file was unencrypted and forbid creating the link.  This behavior
was unexpected because such files are never encrypted; only regular
files, directories, and symlinks can be encrypted.

To fix this, make fscrypt_has_permitted_context() always return true on
special files.

This will be covered by a test in my encryption xfstests patchset.

Fixes: 9bd8212f981e ("ext4 crypto: add encryption policy and password salt support")
Signed-off-by: Eric Biggers <ebiggers@google.com>
Reviewed-by: Richard Weinberger <richard@nod.at>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
fs/ext4/crypto_policy.c
fs/f2fs/crypto_policy.c

index 8a9feb341f314ea94f7f4e5984aea57f4b8e20a4..dd561f916f0b810f4bb80f0147edf249058c953e 100644 (file)
@@ -156,6 +156,12 @@ int ext4_is_child_context_consistent_with_parent(struct inode *parent,
                WARN_ON(1);     /* Should never happen */
                return 0;
        }
+
+       /* No restrictions on file types which are never encrypted */
+       if (!S_ISREG(child->i_mode) && !S_ISDIR(child->i_mode) &&
+           !S_ISLNK(child->i_mode))
+               return 1;
+
        /* no restrictions if the parent directory is not encrypted */
        if (!ext4_encrypted_inode(parent))
                return 1;
index e504f548b64e3045177ae884b3352ac34bd7466e..5bbd1989d5e618bf094249f2f64f345dbf3c0743 100644 (file)
@@ -149,6 +149,11 @@ int f2fs_is_child_context_consistent_with_parent(struct inode *parent,
                BUG_ON(1);
        }
 
+       /* No restrictions on file types which are never encrypted */
+       if (!S_ISREG(child->i_mode) && !S_ISDIR(child->i_mode) &&
+           !S_ISLNK(child->i_mode))
+               return 1;
+
        /* no restrictions if the parent directory is not encrypted */
        if (!f2fs_encrypted_inode(parent))
                return 1;