diff --git a/drivers/mmc/card/block.c b/drivers/mmc/card/block.c
index e62fde3ac431c111ec945d4aba9c877f6308d81d..c13ba2ab19d63663ba72c08b969ef6bc38f9e7bf 100644
--- a/drivers/mmc/card/block.c
+++ b/drivers/mmc/card/block.c
@@ -355,8 +355,10 @@ static struct mmc_blk_ioc_data *mmc_blk_ioctl_copy_from_user(
 		goto idata_err;
 	}
 
-	if (!idata->buf_bytes)
+	if (!idata->buf_bytes) {
+		idata->buf = NULL;
 		return idata;
+	}
 
 	idata->buf = kmalloc(idata->buf_bytes, GFP_KERNEL);
 	if (!idata->buf) {