HID: wacom: Check for string overflow from strscpy calls

The strscpy function is able to return an error code when a copy would
overflow the size of the destination. The copy is stopped and the buffer
terminated before overflow actually occurs so it is safe to continue
execution, but we should still produce a warning should this occur.

Signed-off-by: Jason Gerecke <[email protected]>
Reviewed-by: Ping Cheng <[email protected]>
Reviewed-by: Peter Hutterer <[email protected]>
Signed-off-by: Jiri Kosina <[email protected]>
[[email protected]: Imported into input-wacom repository (d9eef346b601)]
Signed-off-by: Joshua Dickens <[email protected]>

Author: jigpu

4.5/wacom_sys.c

@@ -2284,7 +2284,9 @@ static void wacom_update_name(struct wacom *wacom, const char *suffix)
 		} else if (strstr(product_name, "Wacom") ||
 			   strstr(product_name, "wacom") ||
 			   strstr(product_name, "WACOM")) {
-			strscpy(name, product_name, sizeof(name));
+			if (strscpy(name, product_name, sizeof(name)) < 0) {
+				hid_warn(wacom->hdev, "String overflow while assembling device name");
+			}
 		} else {
 			snprintf(name, sizeof(name), "Wacom %s", product_name);
 		}
@@ -2302,7 +2304,9 @@ static void wacom_update_name(struct wacom *wacom, const char *suffix)
 		if (name[strlen(name)-1] == ' ')
 			name[strlen(name)-1] = '\0';
 	} else {
-		strscpy(name, features->name, sizeof(name));
+		if (strscpy(name, features->name, sizeof(name)) < 0) {
+			hid_warn(wacom->hdev, "String overflow while assembling device name");
+		}
 	}
 
 	snprintf(wacom_wac->name, sizeof(wacom_wac->name), "%s%s",
@@ -2560,8 +2564,10 @@ static void wacom_wireless_work(struct work_struct *work)
 				goto fail;
 		}
 
-		strscpy(wacom_wac->name, wacom_wac1->name,
-			sizeof(wacom_wac->name));
+		if (strscpy(wacom_wac->name, wacom_wac1->name,
+			sizeof(wacom_wac->name)) < 0) {
+			hid_warn(wacom->hdev, "String overflow while assembling device name");
+		}
 	}
 
 	return;