ceph: fix base64 encoded name's length check in ceph_fname_to_usr()

The fname->name is based64_encoded names and the max long shouldn't
exceed the NAME_MAX.

The FSCRYPT_BASE64URL_CHARS(NAME_MAX) will be 255 * 4 / 3.

Signed-off-by: Xiubo Li <xiubli@redhat.com>
Signed-off-by: Jeff Layton <jlayton@kernel.org>

diff --git a/fs/ceph/crypto.c b/fs/ceph/crypto.c
index 7e1f66b350954231f4ab34be1e4999b5144368e0..6fb2fd1a8af06449489ee431483822169e693ff9 100644 (file)
--- a/fs/ceph/crypto.c
+++ b/fs/ceph/crypto.c
@@ -264,7 +264,7 @@ int ceph_fname_to_usr(const struct ceph_fname *fname, struct fscrypt_str *tname,
        }
 
        /* Sanity check that the resulting name will fit in the buffer */
-       if (fname->name_len > FSCRYPT_BASE64URL_CHARS(NAME_MAX))
+       if (fname->name_len > NAME_MAX || fname->ctext_len > NAME_MAX)
                return -EIO;
 
        ret = __fscrypt_prepare_readdir(fname->dir);