ext4: fix memory leak when symlink decryption fails

commit dcce7a46 upstream.

This bug was introduced in v4.8-rc1.
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

fs/ext4/symlink.c

@@ -65,13 +65,12 @@ static const char *ext4_encrypted_get_link(struct dentry *dentry,
 	res = fscrypt_fname_alloc_buffer(inode, cstr.len, &pstr);
 	if (res)
 		goto errout;
+	paddr = pstr.name;
 
 	res = fscrypt_fname_disk_to_usr(inode, 0, 0, &cstr, &pstr);
 	if (res < 0)
 		goto errout;
 
-	paddr = pstr.name;
-
 	/* Null-terminate the name */
 	if (res <= pstr.len)
 		paddr[res] = '\0';