[asan] Intercept all Heap* related imports from ucrtbase.dll
ucrtbase.dll appears to be built with some kind of cross-module
inlining, because there are calls to imported Heap* routines sprinkled
throughout the code. This inlining defeats our attempts to hotpatch
malloc, _malloc_base, and related functions. Failing to intercept an
allocation or deallocation results in a crash when the program attempts
to deallocate or reallocate memory with the wrong allocator.
This change patches the IAT of ucrtbase.dll to replace the addresses of
the imported Heap* functions with implementations provided by ASan. We
don't globally intercept the win32 Heap* functions because they are
typically used by system DLLs that run before ASan initializes.
Eventually, we may want to intercept them, but for now I think this is
the minimal change that will keep ASan stable.
Reviewers: samsonov
Differential Revision: http://reviews.llvm.org/D18413
llvm-svn: 264327
diff --git a/compiler-rt/lib/interception/interception_win.cc b/compiler-rt/lib/interception/interception_win.cc
index efc53dc..89d52b0 100644
--- a/compiler-rt/lib/interception/interception_win.cc
+++ b/compiler-rt/lib/interception/interception_win.cc
@@ -194,14 +194,14 @@
static void **InterestingDLLsAvailable() {
const char *InterestingDLLs[] = {
- "kernel32.dll",
- "msvcr110.dll", // VS2012
- "msvcr120.dll", // VS2013
- "ucrtbase.dll", // Universal CRT
- // NTDLL should go last as it exports some functions that we should override
- // in the CRT [presumably only used internally].
- "ntdll.dll", NULL
- };
+ "kernel32.dll",
+ "msvcr110.dll", // VS2012
+ "msvcr120.dll", // VS2013
+ "vcruntime140.dll", // VS2015
+ "ucrtbase.dll", // Universal CRT
+ // NTDLL should go last as it exports some functions that we should
+ // override in the CRT [presumably only used internally].
+ "ntdll.dll", NULL};
static void *result[ARRAY_SIZE(InterestingDLLs)] = { 0 };
if (!result[0]) {
for (size_t i = 0, j = 0; InterestingDLLs[i]; ++i) {
@@ -278,6 +278,71 @@
return OverrideFunction(orig_func, new_func, orig_old_func);
}
+bool OverrideImportedFunction(const char *module_to_patch,
+ const char *imported_module,
+ const char *function_name, uptr new_function,
+ uptr *orig_old_func) {
+ HMODULE module = GetModuleHandleA(module_to_patch);
+ if (!module)
+ return false;
+
+ // Check that the module header is full and present.
+ RVAPtr<IMAGE_DOS_HEADER> dos_stub(module, 0);
+ RVAPtr<IMAGE_NT_HEADERS> headers(module, dos_stub->e_lfanew);
+ if (!module || dos_stub->e_magic != IMAGE_DOS_SIGNATURE || // "MZ"
+ headers->Signature != IMAGE_NT_SIGNATURE || // "PE\0\0"
+ headers->FileHeader.SizeOfOptionalHeader <
+ sizeof(IMAGE_OPTIONAL_HEADER)) {
+ return false;
+ }
+
+ IMAGE_DATA_DIRECTORY *import_directory =
+ &headers->OptionalHeader.DataDirectory[IMAGE_DIRECTORY_ENTRY_IMPORT];
+
+ // Iterate the list of imported DLLs. FirstThunk will be null for the last
+ // entry.
+ RVAPtr<IMAGE_IMPORT_DESCRIPTOR> imports(module,
+ import_directory->VirtualAddress);
+ for (; imports->FirstThunk != 0; ++imports) {
+ RVAPtr<const char> modname(module, imports->Name);
+ if (_stricmp(&*modname, imported_module) == 0)
+ break;
+ }
+ if (imports->FirstThunk == 0)
+ return false;
+
+ // We have two parallel arrays: the import address table (IAT) and the table
+ // of names. They start out containing the same data, but the loader rewrites
+ // the IAT to hold imported addresses and leaves the name table in
+ // OriginalFirstThunk alone.
+ RVAPtr<IMAGE_THUNK_DATA> name_table(module, imports->OriginalFirstThunk);
+ RVAPtr<IMAGE_THUNK_DATA> iat(module, imports->FirstThunk);
+ for (; name_table->u1.Ordinal != 0; ++name_table, ++iat) {
+ if (!IMAGE_SNAP_BY_ORDINAL(name_table->u1.Ordinal)) {
+ RVAPtr<IMAGE_IMPORT_BY_NAME> import_by_name(
+ module, name_table->u1.ForwarderString);
+ const char *funcname = &import_by_name->Name[0];
+ if (strcmp(funcname, function_name) == 0)
+ break;
+ }
+ }
+ if (name_table->u1.Ordinal == 0)
+ return false;
+
+ // Now we have the correct IAT entry. Do the swap. We have to make the page
+ // read/write first.
+ if (orig_old_func)
+ *orig_old_func = iat->u1.AddressOfData;
+ DWORD old_prot, unused_prot;
+ if (!VirtualProtect(&iat->u1.AddressOfData, 4, PAGE_EXECUTE_READWRITE,
+ &old_prot))
+ return false;
+ iat->u1.AddressOfData = new_function;
+ if (!VirtualProtect(&iat->u1.AddressOfData, 4, old_prot, &unused_prot))
+ return false; // Not clear if this failure bothers us.
+ return true;
+}
+
} // namespace __interception
#endif // _WIN32
