diff --git a/openmp/runtime/src/kmp_affinity.cpp b/openmp/runtime/src/kmp_affinity.cpp
--- a/openmp/runtime/src/kmp_affinity.cpp
+++ b/openmp/runtime/src/kmp_affinity.cpp
@@ -2176,6 +2176,10 @@
     // FIXME - this will match "node_<n> <garbage>"
     unsigned level;
     if (KMP_SSCANF(buf, "node_%u id", &level) == 1) {
+      // validate the input fisrt:
+      if (level > (unsigned)__kmp_xproc) { // level is too big
+        level = __kmp_xproc;
+      }
       if (nodeIdIndex + level >= maxIndex) {
         maxIndex = nodeIdIndex + level;
       }
@@ -4346,8 +4350,6 @@
         depth = __kmp_affinity_create_hwloc_map(&address2os, &msg_id);
         if (depth == 0) {
           KMP_EXIT_AFF_NONE;
-        } else if (depth < 0 && __kmp_affinity_verbose) {
-          KMP_INFORM(AffIgnoringHwloc, "KMP_AFFINITY");
         }
       } else if (__kmp_affinity_verbose) {
         KMP_INFORM(AffIgnoringHwloc, "KMP_AFFINITY");
diff --git a/openmp/runtime/src/kmp_runtime.cpp b/openmp/runtime/src/kmp_runtime.cpp
--- a/openmp/runtime/src/kmp_runtime.cpp
+++ b/openmp/runtime/src/kmp_runtime.cpp
@@ -6487,7 +6487,7 @@
       file_name = tail;
       if (tail != NULL) {
         long *flag_addr = 0;
-        long flag_val = 0;
+        unsigned long flag_val = 0;
         KMP_SSCANF(flag_addr_str, "%p", RCAST(void **, &flag_addr));
         KMP_SSCANF(flag_val_str, "%lx", &flag_val);
         if (flag_addr != 0 && flag_val != 0 && strcmp(file_name, "") != 0) {
diff --git a/openmp/runtime/src/kmp_taskdeps.h b/openmp/runtime/src/kmp_taskdeps.h
--- a/openmp/runtime/src/kmp_taskdeps.h
+++ b/openmp/runtime/src/kmp_taskdeps.h
@@ -23,6 +23,7 @@
     return;
 
   kmp_int32 n = KMP_ATOMIC_DEC(&node->dn.nrefs) - 1;
+  KMP_DEBUG_ASSERT(n >= 0);
   if (n == 0) {
     KMP_ASSERT(node->dn.nrefs == 0);
 #if USE_FAST_MEMORY