[core] fix out-of-bounds access when symmetrizing in builder.h

This bug reaches out of max bound of invs_needed and adds an unpredictable value to total_missing_inv
sbeamer · Oct 2, 2023 · 24261d2 · 24261d2
1 parent 403fc77
commit 24261d2
Showing 1 changed file with 2 additions and 1 deletion.
diff --git a/src/builder.h b/src/builder.h
@@ -247,10 +247,11 @@ class BuilderBase {
       }
       // increase offsets to account for missing inverses, realloc neighs
       SGOffset total_missing_inv = 0;
-      for (NodeID_ n = 0; n <= num_nodes_; n++) {
+      for (NodeID_ n = 0; n < num_nodes_; n++) {
         offsets[n] += total_missing_inv;
         total_missing_inv += invs_needed[n];
       }
+      offsets[num_nodes_] += total_missing_inv;
       size_t newsize = (offsets[num_nodes_] * sizeof(DestID_));
       *neighs = static_cast<DestID_*>(std::realloc(*neighs, newsize));
       if (*neighs == nullptr) {