--- libmalloc/libmalloc-140.40.1/tests/asan.c
+++ libmalloc/libmalloc-409.60.6/tests/asan.c
@@ -1,10 +1,106 @@
+#include <darwintest.h>
+#include <dlfcn.h>
+#include <malloc/malloc.h>
+#include <setjmp.h>
 #include <stdlib.h>
+#include "sanitizer/asan_interface.h"
 
-#include <darwintest.h>
+T_GLOBAL_META(T_META_RUN_CONCURRENTLY(true));
 
-T_DECL(asan_sanity, "ASan Sanity Check",
-		T_META_CHECK_LEAKS(NO)){
+T_DECL(asan_sanity, "ASan Sanity Check", T_META_CHECK_LEAKS(NO))
+{
+	const char *dylib_path =
+		TARGET_OS_OSX    ? "@rpath/libclang_rt.asan_osx_dynamic.dylib" :
+		TARGET_OS_IOS    ? "@rpath/libclang_rt.asan_ios_dynamic.dylib" :
+		TARGET_OS_TV     ? "@rpath/libclang_rt.asan_tvos_dynamic.dylib" :
+		TARGET_OS_WATCH  ? "@rpath/libclang_rt.asan_watchos_dynamic.dylib" :
+		TARGET_OS_BRIDGE ? "@rpath/libclang_rt.asan_bridgeos_dynamic.dylib" :
+		NULL;
+
+	void *asan_dylib = dlopen(dylib_path, RTLD_NOLOAD);
+	T_ASSERT_NOTNULL(asan_dylib, "ASan dylib loaded");
+
 	void *ptr = malloc(16);
 	free(ptr);
+	
 	T_PASS("I didn't crash!");
 }
+
+jmp_buf longjmp_env = {0};
+bool asan_report_hit = false;
+char *asan_report = NULL;
+
+void asan_report_handler(const char *report) {
+	asan_report_hit = true;
+	asan_report = strdup(report);
+	longjmp(longjmp_env, 1);
+}
+
+__attribute__((optnone, noinline))
+void write_byte(void *ptr, size_t offset) {
+	((char *)ptr)[offset] = 'x';
+}
+
+T_DECL(asan_use_after_free, "ASan Detects use-after-free", T_META_CHECK_LEAKS(NO))
+{
+	asan_report = NULL;
+	asan_report_hit = false;
+	__asan_set_error_report_callback(asan_report_handler);
+
+	if (setjmp(longjmp_env) == 0) {
+		char *ptr = malloc(16);
+		free(ptr);
+		write_byte(ptr, 10);
+
+		T_FAIL("use-after-free not detected");
+	}
+
+	T_EXPECT_EQ(asan_report_hit, true, "asan finds use-after-free");
+	T_EXPECT_NOTNULL(strstr(asan_report, "AddressSanitizer: heap-use-after-free"), "asan header");
+}
+
+T_DECL(asan_heap_buffer_overflow, "ASan Detects heap-buffer-overflow", T_META_CHECK_LEAKS(NO))
+{
+	asan_report = NULL;
+	asan_report_hit = false;
+	__asan_set_error_report_callback(asan_report_handler);
+
+	if (setjmp(longjmp_env) == 0) {
+		char *ptr = malloc(16);
+		write_byte(ptr, 17);
+		free(ptr);
+
+		T_FAIL("heap-buffer-overflow not detected");
+	}
+
+	T_EXPECT_EQ(asan_report_hit, true, "asan finds heap-buffer-overflow");
+	T_EXPECT_NOTNULL(strstr(asan_report, "AddressSanitizer: heap-buffer-overflow"), "asan header");
+}
+
+static malloc_zone_t *
+call_malloc_zone_from_ptr(void)
+{
+	void *ptr = malloc(5);
+	malloc_zone_t *zone = malloc_zone_from_ptr(ptr);
+	free(ptr);
+	return zone;
+}
+
+extern int32_t malloc_num_zones;
+extern malloc_zone_t **malloc_zones;
+T_DECL(asan_zone0, "Ensure we return the real zone 0 (not the virtual zone)")
+{
+	malloc_zone_t *zone0 = malloc_zones[0];
+	T_EXPECT_EQ(malloc_default_zone(), zone0, NULL);
+	T_EXPECT_EQ(call_malloc_zone_from_ptr(), zone0, NULL);
+}
+
+T_DECL(pgm_interaction, "Ensure we never enable PGM together with ASan",
+		T_META_ENVVAR("MallocProbGuard=1"))
+{
+	for (uint32_t i = 0; i < malloc_num_zones; i++) {
+		const char *zone_name = malloc_get_zone_name(malloc_zones[i]);
+		T_QUIET; T_EXPECT_NE_STR(zone_name, "ProbGuardMallocZone", NULL);
+	}
+	T_PASS("No PGM zone installed");
+}