commit 0d240e7807ffbc5084db156192589c852e30aeee
author AndreyChurbanov <andrey.churbanov@intel.com> Wed Oct 27 16:38:09 2021 +0300
committer Copybara-Service <copybara-worker@google.com> Wed Oct 27 07:01:05 2021 -0700
tree 2eea90436bc39dce8ec5bb252a3f6eb6be7e4cd7
parent 57488e91be47afc92a36da93a4c2803b3ce15903

[OpenMP] libomp: Fix possible NULL dereference.

According to dlsym description, the value of symbol could be NULL,
and there is no error in this case. Thus dlerror will also return NULL in
this case. We need to check the value returned by dlerror before printing it.

Differential Revision: https://reviews.llvm.org/D112174

GitOrigin-RevId: c704b25b449418217f2e3ee41c100f3ee9a59e4c

runtime/src/ompt-general.cpp

diff --git a/runtime/src/ompt-general.cpp b/runtime/src/ompt-general.cpp
index 89cd23c..c4a9be8 100644
--- a/runtime/src/ompt-general.cpp
+++ b/runtime/src/ompt-general.cpp
@@ -346,9 +346,16 @@
         OMPT_VERBOSE_INIT_CONTINUED_PRINT("Success. \n");
         OMPT_VERBOSE_INIT_PRINT("Searching for ompt_start_tool in %s... ",
                                 fname);
+        dlerror(); // Clear any existing error
         start_tool = (ompt_start_tool_t)dlsym(h, "ompt_start_tool");
         if (!start_tool) {
-          OMPT_VERBOSE_INIT_CONTINUED_PRINT("Failed: %s\n", dlerror());
+          char *error = dlerror();
+          if (error != NULL) {
+            OMPT_VERBOSE_INIT_CONTINUED_PRINT("Failed: %s\n", error);
+          } else {
+            OMPT_VERBOSE_INIT_CONTINUED_PRINT("Failed: %s\n",
+                                              "ompt_start_tool = NULL");
+          }
         } else
 #elif KMP_OS_WINDOWS
       OMPT_VERBOSE_INIT_PRINT("Opening %s... ", fname);