[CrOS Tether] Fix a buffer overflow issue caught by the ASAN bots.

chromeos/components/tether/ble_scanner.cc

Index: chromeos/components/tether/ble_scanner.cc
diff --git a/chromeos/components/tether/ble_scanner.cc b/chromeos/components/tether/ble_scanner.cc
index 5ed761d731f36c666f7f003c9d16dd78ba10e20e..45d550bfea6914072da5db72727350535f8dae83 100644
--- a/chromeos/components/tether/ble_scanner.cc
+++ b/chromeos/components/tether/ble_scanner.cc
@@ -228,7 +228,8 @@ void BleScanner::HandleDeviceUpdated(
   std::string service_data_str;
   char* string_contents_ptr =
       base::WriteInto(&service_data_str, service_data->size() + 1);
-  memcpy(string_contents_ptr, service_data->data(), service_data->size() + 1);
+  memcpy(string_contents_ptr, service_data->data(), service_data->size());
+  string_contents_ptr[service_data->size()] = '\0';

[Lei Zhang, 2017/06/16 22:57:37]

Do you actually need to NUL-terminate the raw string buffer inside a
std::string?

[Kyle Horimoto, 2017/06/16 23:05:04]

I checked, and you don't. Removed.

 
   CheckForMatchingScanFilters(bluetooth_device, service_data_str);
 }