summaryrefslogtreecommitdiff
diff options
context:
space:
mode:
-rw-r--r--block/qed.c6
1 files changed, 4 insertions, 2 deletions
diff --git a/block/qed.c b/block/qed.c
index e87dc4decf..7fab155b1a 100644
--- a/block/qed.c
+++ b/block/qed.c
@@ -1425,8 +1425,10 @@ static int bdrv_qed_change_backing_file(BlockDriverState *bs,
memcpy(buffer, &le_header, sizeof(le_header));
buffer_len = sizeof(le_header);
- memcpy(buffer + buffer_len, backing_file, backing_file_len);
- buffer_len += backing_file_len;
+ if (backing_file) {
+ memcpy(buffer + buffer_len, backing_file, backing_file_len);
+ buffer_len += backing_file_len;
+ }
/* Write new header */
ret = bdrv_pwrite_sync(bs->file, 0, buffer, buffer_len);