llvm-project/compiler-rt/lib/asan/asan_malloc_win.cpp

552 lines
20 KiB
C++

//===-- asan_malloc_win.cpp -----------------------------------------------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
//
// This file is a part of AddressSanitizer, an address sanity checker.
//
// Windows-specific malloc interception.
//===----------------------------------------------------------------------===//
#include "sanitizer_common/sanitizer_allocator_interface.h"
#include "sanitizer_common/sanitizer_platform.h"
#if SANITIZER_WINDOWS
#include "asan_allocator.h"
#include "asan_interceptors.h"
#include "asan_internal.h"
#include "asan_stack.h"
#include "interception/interception.h"
#include <stddef.h>
// Intentionally not including windows.h here, to avoid the risk of
// pulling in conflicting declarations of these functions. (With mingw-w64,
// there's a risk of windows.h pulling in stdint.h.)
typedef int BOOL;
typedef void *HANDLE;
typedef const void *LPCVOID;
typedef void *LPVOID;
typedef unsigned long DWORD;
constexpr unsigned long HEAP_ZERO_MEMORY = 0x00000008;
constexpr unsigned long HEAP_REALLOC_IN_PLACE_ONLY = 0x00000010;
constexpr unsigned long HEAP_ALLOCATE_SUPPORTED_FLAGS = (HEAP_ZERO_MEMORY);
constexpr unsigned long HEAP_ALLOCATE_UNSUPPORTED_FLAGS =
(~HEAP_ALLOCATE_SUPPORTED_FLAGS);
constexpr unsigned long HEAP_FREE_UNSUPPORTED_FLAGS =
(~HEAP_ALLOCATE_SUPPORTED_FLAGS);
constexpr unsigned long HEAP_REALLOC_UNSUPPORTED_FLAGS =
(~HEAP_ALLOCATE_SUPPORTED_FLAGS);
extern "C" {
LPVOID WINAPI HeapAlloc(HANDLE hHeap, DWORD dwFlags, size_t dwBytes);
LPVOID WINAPI HeapReAlloc(HANDLE hHeap, DWORD dwFlags, LPVOID lpMem,
size_t dwBytes);
BOOL WINAPI HeapFree(HANDLE hHeap, DWORD dwFlags, LPVOID lpMem);
size_t WINAPI HeapSize(HANDLE hHeap, DWORD dwFlags, LPCVOID lpMem);
BOOL WINAPI HeapValidate(HANDLE hHeap, DWORD dwFlags, LPCVOID lpMem);
}
using namespace __asan;
// MT: Simply defining functions with the same signature in *.obj
// files overrides the standard functions in the CRT.
// MD: Memory allocation functions are defined in the CRT .dll,
// so we have to intercept them before they are called for the first time.
#if ASAN_DYNAMIC
# define ALLOCATION_FUNCTION_ATTRIBUTE
#else
# define ALLOCATION_FUNCTION_ATTRIBUTE SANITIZER_INTERFACE_ATTRIBUTE
#endif
extern "C" {
ALLOCATION_FUNCTION_ATTRIBUTE
size_t _msize(void *ptr) {
GET_CURRENT_PC_BP_SP;
(void)sp;
return asan_malloc_usable_size(ptr, pc, bp);
}
ALLOCATION_FUNCTION_ATTRIBUTE
size_t _msize_base(void *ptr) {
return _msize(ptr);
}
ALLOCATION_FUNCTION_ATTRIBUTE
void free(void *ptr) {
GET_STACK_TRACE_FREE;
return asan_free(ptr, &stack, FROM_MALLOC);
}
ALLOCATION_FUNCTION_ATTRIBUTE
void _free_dbg(void *ptr, int) {
free(ptr);
}
ALLOCATION_FUNCTION_ATTRIBUTE
void _free_base(void *ptr) {
free(ptr);
}
ALLOCATION_FUNCTION_ATTRIBUTE
void *malloc(size_t size) {
GET_STACK_TRACE_MALLOC;
return asan_malloc(size, &stack);
}
ALLOCATION_FUNCTION_ATTRIBUTE
void *_malloc_base(size_t size) {
return malloc(size);
}
ALLOCATION_FUNCTION_ATTRIBUTE
void *_malloc_dbg(size_t size, int, const char *, int) {
return malloc(size);
}
ALLOCATION_FUNCTION_ATTRIBUTE
void *calloc(size_t nmemb, size_t size) {
GET_STACK_TRACE_MALLOC;
return asan_calloc(nmemb, size, &stack);
}
ALLOCATION_FUNCTION_ATTRIBUTE
void *_calloc_base(size_t nmemb, size_t size) {
return calloc(nmemb, size);
}
ALLOCATION_FUNCTION_ATTRIBUTE
void *_calloc_dbg(size_t nmemb, size_t size, int, const char *, int) {
return calloc(nmemb, size);
}
ALLOCATION_FUNCTION_ATTRIBUTE
void *_calloc_impl(size_t nmemb, size_t size, int *errno_tmp) {
return calloc(nmemb, size);
}
ALLOCATION_FUNCTION_ATTRIBUTE
void *realloc(void *ptr, size_t size) {
GET_STACK_TRACE_MALLOC;
return asan_realloc(ptr, size, &stack);
}
ALLOCATION_FUNCTION_ATTRIBUTE
void *_realloc_dbg(void *ptr, size_t size, int) {
UNREACHABLE("_realloc_dbg should not exist!");
return 0;
}
ALLOCATION_FUNCTION_ATTRIBUTE
void *_realloc_base(void *ptr, size_t size) {
return realloc(ptr, size);
}
ALLOCATION_FUNCTION_ATTRIBUTE
void *_recalloc(void *p, size_t n, size_t elem_size) {
if (!p)
return calloc(n, elem_size);
const size_t size = n * elem_size;
if (elem_size != 0 && size / elem_size != n)
return 0;
size_t old_size = _msize(p);
void *new_alloc = malloc(size);
if (new_alloc) {
REAL(memcpy)(new_alloc, p, Min<size_t>(size, old_size));
if (old_size < size)
REAL(memset)(((u8 *)new_alloc) + old_size, 0, size - old_size);
free(p);
}
return new_alloc;
}
ALLOCATION_FUNCTION_ATTRIBUTE
void *_recalloc_base(void *p, size_t n, size_t elem_size) {
return _recalloc(p, n, elem_size);
}
ALLOCATION_FUNCTION_ATTRIBUTE
void *_expand(void *memblock, size_t size) {
// _expand is used in realloc-like functions to resize the buffer if possible.
// We don't want memory to stand still while resizing buffers, so return 0.
return 0;
}
ALLOCATION_FUNCTION_ATTRIBUTE
void *_expand_dbg(void *memblock, size_t size) {
return _expand(memblock, size);
}
// TODO(timurrrr): Might want to add support for _aligned_* allocation
// functions to detect a bit more bugs. Those functions seem to wrap malloc().
int _CrtDbgReport(int, const char*, int,
const char*, const char*, ...) {
ShowStatsAndAbort();
}
int _CrtDbgReportW(int reportType, const wchar_t*, int,
const wchar_t*, const wchar_t*, ...) {
ShowStatsAndAbort();
}
int _CrtSetReportMode(int, int) {
return 0;
}
} // extern "C"
#define OWNED_BY_RTL(heap, memory) \
(!__sanitizer_get_ownership(memory) && HeapValidate(heap, 0, memory))
INTERCEPTOR_WINAPI(size_t, HeapSize, HANDLE hHeap, DWORD dwFlags,
LPCVOID lpMem) {
// If the RTL allocators are hooked we need to check whether the ASAN
// allocator owns the pointer we're about to use. Allocations occur before
// interception takes place, so if it is not owned by the RTL heap we can
// pass it to the ASAN heap for inspection.
if (flags()->windows_hook_rtl_allocators) {
if (!asan_inited || OWNED_BY_RTL(hHeap, lpMem))
return REAL(HeapSize)(hHeap, dwFlags, lpMem);
} else {
CHECK(dwFlags == 0 && "unsupported heap flags");
}
GET_CURRENT_PC_BP_SP;
(void)sp;
return asan_malloc_usable_size(lpMem, pc, bp);
}
INTERCEPTOR_WINAPI(LPVOID, HeapAlloc, HANDLE hHeap, DWORD dwFlags,
size_t dwBytes) {
// If the ASAN runtime is not initialized, or we encounter an unsupported
// flag, fall back to the original allocator.
if (flags()->windows_hook_rtl_allocators) {
if (UNLIKELY(!asan_inited ||
(dwFlags & HEAP_ALLOCATE_UNSUPPORTED_FLAGS) != 0)) {
return REAL(HeapAlloc)(hHeap, dwFlags, dwBytes);
}
} else {
// In the case that we don't hook the rtl allocators,
// this becomes an assert since there is no failover to the original
// allocator.
CHECK((HEAP_ALLOCATE_UNSUPPORTED_FLAGS & dwFlags) != 0 &&
"unsupported flags");
}
GET_STACK_TRACE_MALLOC;
void *p = asan_malloc(dwBytes, &stack);
// Reading MSDN suggests that the *entire* usable allocation is zeroed out.
// Otherwise it is difficult to HeapReAlloc with HEAP_ZERO_MEMORY.
// https://blogs.msdn.microsoft.com/oldnewthing/20120316-00/?p=8083
if (p && (dwFlags & HEAP_ZERO_MEMORY)) {
GET_CURRENT_PC_BP_SP;
(void)sp;
auto usable_size = asan_malloc_usable_size(p, pc, bp);
internal_memset(p, 0, usable_size);
}
return p;
}
INTERCEPTOR_WINAPI(BOOL, HeapFree, HANDLE hHeap, DWORD dwFlags, LPVOID lpMem) {
// Heap allocations happen before this function is hooked, so we must fall
// back to the original function if the pointer is not from the ASAN heap,
// or unsupported flags are provided.
if (flags()->windows_hook_rtl_allocators) {
if (OWNED_BY_RTL(hHeap, lpMem))
return REAL(HeapFree)(hHeap, dwFlags, lpMem);
} else {
CHECK((HEAP_FREE_UNSUPPORTED_FLAGS & dwFlags) != 0 && "unsupported flags");
}
GET_STACK_TRACE_FREE;
asan_free(lpMem, &stack, FROM_MALLOC);
return true;
}
namespace __asan {
using AllocFunction = LPVOID(WINAPI *)(HANDLE, DWORD, size_t);
using ReAllocFunction = LPVOID(WINAPI *)(HANDLE, DWORD, LPVOID, size_t);
using SizeFunction = size_t(WINAPI *)(HANDLE, DWORD, LPVOID);
using FreeFunction = BOOL(WINAPI *)(HANDLE, DWORD, LPVOID);
void *SharedReAlloc(ReAllocFunction reallocFunc, SizeFunction heapSizeFunc,
FreeFunction freeFunc, AllocFunction allocFunc,
HANDLE hHeap, DWORD dwFlags, LPVOID lpMem, size_t dwBytes) {
CHECK(reallocFunc && heapSizeFunc && freeFunc && allocFunc);
GET_STACK_TRACE_MALLOC;
GET_CURRENT_PC_BP_SP;
(void)sp;
if (flags()->windows_hook_rtl_allocators) {
enum AllocationOwnership { NEITHER = 0, ASAN = 1, RTL = 2 };
AllocationOwnership ownershipState;
bool owned_rtlalloc = false;
bool owned_asan = __sanitizer_get_ownership(lpMem);
if (!owned_asan)
owned_rtlalloc = HeapValidate(hHeap, 0, lpMem);
if (owned_asan && !owned_rtlalloc)
ownershipState = ASAN;
else if (!owned_asan && owned_rtlalloc)
ownershipState = RTL;
else if (!owned_asan && !owned_rtlalloc)
ownershipState = NEITHER;
// If this heap block which was allocated before the ASAN
// runtime came up, use the real HeapFree function.
if (UNLIKELY(!asan_inited)) {
return reallocFunc(hHeap, dwFlags, lpMem, dwBytes);
}
bool only_asan_supported_flags =
(HEAP_REALLOC_UNSUPPORTED_FLAGS & dwFlags) == 0;
if (ownershipState == RTL ||
(ownershipState == NEITHER && !only_asan_supported_flags)) {
if (only_asan_supported_flags) {
// if this is a conversion to ASAN upported flags, transfer this
// allocation to the ASAN allocator
void *replacement_alloc;
if (dwFlags & HEAP_ZERO_MEMORY)
replacement_alloc = asan_calloc(1, dwBytes, &stack);
else
replacement_alloc = asan_malloc(dwBytes, &stack);
if (replacement_alloc) {
size_t old_size = heapSizeFunc(hHeap, dwFlags, lpMem);
if (old_size == ((size_t)0) - 1) {
asan_free(replacement_alloc, &stack, FROM_MALLOC);
return nullptr;
}
REAL(memcpy)(replacement_alloc, lpMem, old_size);
freeFunc(hHeap, dwFlags, lpMem);
}
return replacement_alloc;
} else {
// owned by rtl or neither with unsupported ASAN flags,
// just pass back to original allocator
CHECK(ownershipState == RTL || ownershipState == NEITHER);
CHECK(!only_asan_supported_flags);
return reallocFunc(hHeap, dwFlags, lpMem, dwBytes);
}
}
if (ownershipState == ASAN && !only_asan_supported_flags) {
// Conversion to unsupported flags allocation,
// transfer this allocation back to the original allocator.
void *replacement_alloc = allocFunc(hHeap, dwFlags, dwBytes);
size_t old_usable_size = 0;
if (replacement_alloc) {
old_usable_size = asan_malloc_usable_size(lpMem, pc, bp);
REAL(memcpy)(replacement_alloc, lpMem,
Min<size_t>(dwBytes, old_usable_size));
asan_free(lpMem, &stack, FROM_MALLOC);
}
return replacement_alloc;
}
CHECK((ownershipState == ASAN || ownershipState == NEITHER) &&
only_asan_supported_flags);
// At this point we should either be ASAN owned with ASAN supported flags
// or we owned by neither and have supported flags.
// Pass through even when it's neither since this could be a null realloc or
// UAF that ASAN needs to catch.
} else {
CHECK((HEAP_REALLOC_UNSUPPORTED_FLAGS & dwFlags) != 0 &&
"unsupported flags");
}
// asan_realloc will never reallocate in place, so for now this flag is
// unsupported until we figure out a way to fake this.
if (dwFlags & HEAP_REALLOC_IN_PLACE_ONLY)
return nullptr;
// HeapReAlloc and HeapAlloc both happily accept 0 sized allocations.
// passing a 0 size into asan_realloc will free the allocation.
// To avoid this and keep behavior consistent, fudge the size if 0.
// (asan_malloc already does this)
if (dwBytes == 0)
dwBytes = 1;
size_t old_size;
if (dwFlags & HEAP_ZERO_MEMORY)
old_size = asan_malloc_usable_size(lpMem, pc, bp);
void *ptr = asan_realloc(lpMem, dwBytes, &stack);
if (ptr == nullptr)
return nullptr;
if (dwFlags & HEAP_ZERO_MEMORY) {
size_t new_size = asan_malloc_usable_size(ptr, pc, bp);
if (old_size < new_size)
REAL(memset)(((u8 *)ptr) + old_size, 0, new_size - old_size);
}
return ptr;
}
} // namespace __asan
INTERCEPTOR_WINAPI(LPVOID, HeapReAlloc, HANDLE hHeap, DWORD dwFlags,
LPVOID lpMem, size_t dwBytes) {
return SharedReAlloc(REAL(HeapReAlloc), (SizeFunction)REAL(HeapSize),
REAL(HeapFree), REAL(HeapAlloc), hHeap, dwFlags, lpMem,
dwBytes);
}
// The following functions are undocumented and subject to change.
// However, hooking them is necessary to hook Windows heap
// allocations with detours and their definitions are unlikely to change.
// Comments in /minkernel/ntos/rtl/heappublic.c indicate that these functions
// are part of the heap's public interface.
typedef unsigned long LOGICAL;
// This function is documented as part of the Driver Development Kit but *not*
// the Windows Development Kit.
LOGICAL RtlFreeHeap(void* HeapHandle, DWORD Flags,
void* BaseAddress);
// This function is documented as part of the Driver Development Kit but *not*
// the Windows Development Kit.
void* RtlAllocateHeap(void* HeapHandle, DWORD Flags, size_t Size);
// This function is completely undocumented.
void*
RtlReAllocateHeap(void* HeapHandle, DWORD Flags, void* BaseAddress,
size_t Size);
// This function is completely undocumented.
size_t RtlSizeHeap(void* HeapHandle, DWORD Flags, void* BaseAddress);
INTERCEPTOR_WINAPI(size_t, RtlSizeHeap, HANDLE HeapHandle, DWORD Flags,
void* BaseAddress) {
if (!flags()->windows_hook_rtl_allocators ||
UNLIKELY(!asan_inited || OWNED_BY_RTL(HeapHandle, BaseAddress))) {
return REAL(RtlSizeHeap)(HeapHandle, Flags, BaseAddress);
}
GET_CURRENT_PC_BP_SP;
(void)sp;
return asan_malloc_usable_size(BaseAddress, pc, bp);
}
INTERCEPTOR_WINAPI(BOOL, RtlFreeHeap, HANDLE HeapHandle, DWORD Flags,
void* BaseAddress) {
// Heap allocations happen before this function is hooked, so we must fall
// back to the original function if the pointer is not from the ASAN heap, or
// unsupported flags are provided.
if (!flags()->windows_hook_rtl_allocators ||
UNLIKELY((HEAP_FREE_UNSUPPORTED_FLAGS & Flags) != 0 ||
OWNED_BY_RTL(HeapHandle, BaseAddress))) {
return REAL(RtlFreeHeap)(HeapHandle, Flags, BaseAddress);
}
GET_STACK_TRACE_FREE;
asan_free(BaseAddress, &stack, FROM_MALLOC);
return true;
}
INTERCEPTOR_WINAPI(void*, RtlAllocateHeap, HANDLE HeapHandle, DWORD Flags,
size_t Size) {
// If the ASAN runtime is not initialized, or we encounter an unsupported
// flag, fall back to the original allocator.
if (!flags()->windows_hook_rtl_allocators ||
UNLIKELY(!asan_inited ||
(Flags & HEAP_ALLOCATE_UNSUPPORTED_FLAGS) != 0)) {
return REAL(RtlAllocateHeap)(HeapHandle, Flags, Size);
}
GET_STACK_TRACE_MALLOC;
void *p;
// Reading MSDN suggests that the *entire* usable allocation is zeroed out.
// Otherwise it is difficult to HeapReAlloc with HEAP_ZERO_MEMORY.
// https://blogs.msdn.microsoft.com/oldnewthing/20120316-00/?p=8083
if (Flags & HEAP_ZERO_MEMORY) {
p = asan_calloc(Size, 1, &stack);
} else {
p = asan_malloc(Size, &stack);
}
return p;
}
INTERCEPTOR_WINAPI(void*, RtlReAllocateHeap, HANDLE HeapHandle, DWORD Flags,
void* BaseAddress, size_t Size) {
// If it's actually a heap block which was allocated before the ASAN runtime
// came up, use the real RtlFreeHeap function.
if (!flags()->windows_hook_rtl_allocators)
return REAL(RtlReAllocateHeap)(HeapHandle, Flags, BaseAddress, Size);
return SharedReAlloc(REAL(RtlReAllocateHeap), REAL(RtlSizeHeap),
REAL(RtlFreeHeap), REAL(RtlAllocateHeap), HeapHandle,
Flags, BaseAddress, Size);
}
namespace __asan {
static void TryToOverrideFunction(const char *fname, uptr new_func) {
// Failure here is not fatal. The CRT may not be present, and different CRT
// versions use different symbols.
if (!__interception::OverrideFunction(fname, new_func))
VPrintf(2, "Failed to override function %s\n", fname);
}
void ReplaceSystemMalloc() {
#if defined(ASAN_DYNAMIC)
TryToOverrideFunction("free", (uptr)free);
TryToOverrideFunction("_free_base", (uptr)free);
TryToOverrideFunction("malloc", (uptr)malloc);
TryToOverrideFunction("_malloc_base", (uptr)malloc);
TryToOverrideFunction("_malloc_crt", (uptr)malloc);
TryToOverrideFunction("calloc", (uptr)calloc);
TryToOverrideFunction("_calloc_base", (uptr)calloc);
TryToOverrideFunction("_calloc_crt", (uptr)calloc);
TryToOverrideFunction("realloc", (uptr)realloc);
TryToOverrideFunction("_realloc_base", (uptr)realloc);
TryToOverrideFunction("_realloc_crt", (uptr)realloc);
TryToOverrideFunction("_recalloc", (uptr)_recalloc);
TryToOverrideFunction("_recalloc_base", (uptr)_recalloc);
TryToOverrideFunction("_recalloc_crt", (uptr)_recalloc);
TryToOverrideFunction("_msize", (uptr)_msize);
TryToOverrideFunction("_msize_base", (uptr)_msize);
TryToOverrideFunction("_expand", (uptr)_expand);
TryToOverrideFunction("_expand_base", (uptr)_expand);
if (flags()->windows_hook_rtl_allocators) {
INTERCEPT_FUNCTION(HeapSize);
INTERCEPT_FUNCTION(HeapFree);
INTERCEPT_FUNCTION(HeapReAlloc);
INTERCEPT_FUNCTION(HeapAlloc);
// Undocumented functions must be intercepted by name, not by symbol.
__interception::OverrideFunction("RtlSizeHeap", (uptr)WRAP(RtlSizeHeap),
(uptr *)&REAL(RtlSizeHeap));
__interception::OverrideFunction("RtlFreeHeap", (uptr)WRAP(RtlFreeHeap),
(uptr *)&REAL(RtlFreeHeap));
__interception::OverrideFunction("RtlReAllocateHeap",
(uptr)WRAP(RtlReAllocateHeap),
(uptr *)&REAL(RtlReAllocateHeap));
__interception::OverrideFunction("RtlAllocateHeap",
(uptr)WRAP(RtlAllocateHeap),
(uptr *)&REAL(RtlAllocateHeap));
} else {
#define INTERCEPT_UCRT_FUNCTION(func) \
if (!INTERCEPT_FUNCTION_DLLIMPORT( \
"ucrtbase.dll", "api-ms-win-core-heap-l1-1-0.dll", func)) { \
VPrintf(2, "Failed to intercept ucrtbase.dll import %s\n", #func); \
}
INTERCEPT_UCRT_FUNCTION(HeapAlloc);
INTERCEPT_UCRT_FUNCTION(HeapFree);
INTERCEPT_UCRT_FUNCTION(HeapReAlloc);
INTERCEPT_UCRT_FUNCTION(HeapSize);
#undef INTERCEPT_UCRT_FUNCTION
}
// Recent versions of ucrtbase.dll appear to be built with PGO and LTCG, which
// enable cross-module inlining. This means our _malloc_base hook won't catch
// all CRT allocations. This code here patches the import table of
// ucrtbase.dll so that all attempts to use the lower-level win32 heap
// allocation API will be directed to ASan's heap. We don't currently
// intercept all calls to HeapAlloc. If we did, we would have to check on
// HeapFree whether the pointer came from ASan of from the system.
#endif // defined(ASAN_DYNAMIC)
}
} // namespace __asan
#endif // _WIN32