Fix the potential of a dereference of null pointer.

diff --git a/libarchive/archive_read_support_filter_xz.c b/libarchive/archive_read_support_filter_xz.c
index 7bda2636351df1722b6b8517ee33a69969cbce72..4e0a95feeb0f0a313392f99c2794e71c670e41bd 100644 (file)
--- a/libarchive/archive_read_support_filter_xz.c
+++ b/libarchive/archive_read_support_filter_xz.c
@@ -627,7 +627,7 @@ lzip_tail(struct archive_read_filter *self)
        f = __archive_read_filter_ahead(self->upstream, tail, &avail_in);
        if (f == NULL && avail_in < 0)
                return (ARCHIVE_FATAL);
-       if (avail_in < tail) {
+       if (f == NULL || avail_in < tail) {
                archive_set_error(&self->archive->archive, ARCHIVE_ERRNO_MISC,
                    "Lzip: Remaining data is less bytes");
                return (ARCHIVE_FAILED);