add 1 byte overflow tests

test/simple-memory-corruption/Makefile

@@ -39,8 +39,10 @@ EXECUTABLES := \
     uninitialized_free \
     uninitialized_realloc \
     uninitialized_malloc_usable_size \
-    eight_byte_overflow_small \
+    overflow_large_1_byte \
-    eight_byte_overflow_large \
+    overflow_large_8_byte \
+    overflow_small_1_byte \
+    overflow_small_8_byte \
     string_overflow \
     delete_type_size_mismatch \
     unaligned_malloc_usable_size_small \

test/simple-memory-corruption/overflow_large_1_byte.c

@@ -0,0 +1,14 @@
+#include <stdlib.h>
+
+#include "../test_util.h"
+
+OPTNONE int main(void) {
+    char *p = malloc(256 * 1024);
+    if (!p) {
+        return 1;
+    }
+    size_t size = malloc_usable_size(p);
+    *(p + size) = 0;
+    free(p);
+    return 0;
+}

test/simple-memory-corruption/overflow_small_1_byte.c

@@ -0,0 +1,14 @@
+#include <stdlib.h>
+
+#include "../test_util.h"
+
+OPTNONE int main(void) {
+    char *p = malloc(8);
+    if (!p) {
+        return 1;
+    }
+    size_t size = malloc_usable_size(p);
+    *(p + size) = 1;
+    free(p);
+    return 0;
+}

test/simple-memory-corruption/test_smc.py

@@ -48,14 +48,26 @@ class TestSimpleMemoryCorruption(unittest.TestCase):
         self.assertEqual(stderr.decode("utf-8"),
                          "fatal allocator error: double free (quarantine)\n")
 
-    def test_eight_byte_overflow_large(self):
+    def test_overflow_large_1_byte(self):
         _stdout, _stderr, returncode = self.run_test(
-            "eight_byte_overflow_large")
+            "overflow_large_1_byte")
         self.assertEqual(returncode, -11)
 
-    def test_eight_byte_overflow_small(self):
+    def test_overflow_large_8_byte(self):
+        _stdout, _stderr, returncode = self.run_test(
+            "overflow_large_8_byte")
+        self.assertEqual(returncode, -11)
+
+    def test_overflow_small_1_byte(self):
         _stdout, stderr, returncode = self.run_test(
-            "eight_byte_overflow_small")
+            "overflow_small_1_byte")
+        self.assertEqual(returncode, -6)
+        self.assertEqual(stderr.decode("utf-8"),
+                         "fatal allocator error: canary corrupted\n")
+
+    def test_overflow_small_8_byte(self):
+        _stdout, stderr, returncode = self.run_test(
+            "overflow_small_8_byte")
         self.assertEqual(returncode, -6)
         self.assertEqual(stderr.decode("utf-8"),
                          "fatal allocator error: canary corrupted\n")