diff --git a/drivers/hid/hid-core.c b/drivers/hid/hid-core.c
index 4f3706e..b49211c 100644
--- a/drivers/hid/hid-core.c
+++ b/drivers/hid/hid-core.c
@@ -1407,6 +1407,17 @@
 }
 
 /*
+ * Compute the size of a report.
+ */
+static size_t hid_compute_report_size(struct hid_report *report)
+{
+	if (report->size)
+		return ((report->size - 1) >> 3) + 1;
+
+	return 0;
+}
+
+/*
  * Create a report. 'data' has to be allocated using
  * hid_alloc_report_buf() so that it has proper size.
  */
@@ -1418,7 +1429,7 @@
 	if (report->id > 0)
 		*data++ = report->id;
 
-	memset(data, 0, ((report->size - 1) >> 3) + 1);
+	memset(data, 0, hid_compute_report_size(report));
 	for (n = 0; n < report->maxfield; n++)
 		hid_output_field(report->device, report->field[n], data);
 }
@@ -1545,7 +1556,7 @@
 		csize--;
 	}
 
-	rsize = ((report->size - 1) >> 3) + 1;
+	rsize = hid_compute_report_size(report);
 
 	if (report_enum->numbered && rsize >= HID_MAX_BUFFER_SIZE)
 		rsize = HID_MAX_BUFFER_SIZE - 1;