Fix comparison between unsigned subtraction and the value 0

This is resolved by replacing the unsigned subtraction comparison with 0 in the MinimumHeapGrowth stratedgy check to `free_space != size`. Fixes a false positive, "critical" security bug revealed by codeql in code-scanning/atomvm#30. Signed-off-by: Winford <[email protected]>
UncleGrumpy · Feb 11, 2025 · 116d14a · 116d14a
1 parent 2ac2041
commit 116d14a
Showing 1 changed file with 1 addition and 1 deletion.
diff --git a/src/libAtomVM/memory.c b/src/libAtomVM/memory.c
@@ -167,7 +167,7 @@ enum MemoryGCResult memory_ensure_free_with_roots(Context *c, size_t size, size_
                     should_gc = ((alloc_mode == MEMORY_CAN_SHRINK) && free_space - size > maximum_free_space);
                 } break;
                 case MinimumHeapGrowth:
-                    should_gc = ((alloc_mode == MEMORY_CAN_SHRINK) && free_space - size > 0);
+                    should_gc = ((alloc_mode == MEMORY_CAN_SHRINK) && free_space > size);
                     break;
                 case FibonacciHeapGrowth: {
                     memory_size = memory_heap_memory_size(&c->heap);