Merge pull request #2474 from nrspruit/fix_use_after_free_build_strings

[L0] Fix use after free with Module build strings

Author: martygrant

source/adapters/level_zero/program.cpp

@@ -452,11 +452,9 @@ ur_result_t urProgramLinkExp(
       // Build flags may be different for different devices, so handle them
       // here. Clear values of the previous device first.
       BuildFlagPtrs.clear();
-      std::vector<std::string> TemporaryOptionsStrings;
       for (uint32_t I = 0; I < count; I++) {
-        TemporaryOptionsStrings.push_back(
-            phPrograms[I]->getBuildOptions(ZeDevice));
-        BuildFlagPtrs.push_back(TemporaryOptionsStrings.back().c_str());
+        BuildFlagPtrs.push_back(
+            phPrograms[I]->getBuildOptions(ZeDevice).c_str());
       }
       ZeExtModuleDesc.pBuildFlags = BuildFlagPtrs.data();
       if (count == 1)

source/adapters/level_zero/program.hpp

@@ -169,7 +169,7 @@ struct ur_program_handle_t_ : _ur_object {
     DeviceDataMap[ZeDevice].BuildFlags += Options;
   }
 
-  std::string getBuildOptions(ze_device_handle_t ZeDevice) {
+  std::string &getBuildOptions(ze_device_handle_t ZeDevice) {
     return DeviceDataMap[ZeDevice].BuildFlags;
   }