diff --git a/drivers/hid/hid-core.c b/drivers/hid/hid-core.c
index 1a794c3aecd..119b11178bb 100644
--- a/drivers/hid/hid-core.c
+++ b/drivers/hid/hid-core.c
@@ -1170,6 +1170,17 @@ static void hid_output_field(const struct hid_device *hid,
 	}
 }
 
+/*
+ * 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.
  */
@@ -1181,7 +1192,7 @@ void hid_output_report(struct hid_report *report, __u8 *data)
 	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);
 }
@@ -1256,7 +1267,7 @@ int hid_report_raw_event(struct hid_device *hid, int type, u8 *data, int size,
 		csize--;
 	}
 
-	rsize = ((report->size - 1) >> 3) + 1;
+	rsize = hid_compute_report_size(report);
 
 	if (rsize > HID_MAX_BUFFER_SIZE)
 		rsize = HID_MAX_BUFFER_SIZE;