1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
|
// Copyright (c) 2013 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <algorithm>
#include <limits>
#include "base/logging.h"
#include "base/memory/scoped_ptr.h"
#include "testing/gtest/include/gtest/gtest.h"
using std::nothrow;
using std::numeric_limits;
namespace {
// Check that we can not allocate a memory range that cannot be indexed
// via an int. This is used to mitigate vulnerabilities in libraries that use
// int instead of size_t.
// See crbug.com/169327.
// - NO_TCMALLOC because we only patched tcmalloc
// - ADDRESS_SANITIZER because it has its own memory allocator
// - IOS does not seem to honor nothrow in new properly
// - OS_MACOSX does not use tcmalloc
#if !defined(NO_TCMALLOC) && !defined(ADDRESS_SANITIZER) && \
!defined(OS_IOS) && !defined(OS_MACOSX)
#define ALLOC_TEST(function) function
#else
#define ALLOC_TEST(function) DISABLED_##function
#endif
// TODO(jln): switch to std::numeric_limits<int>::max() when we switch to
// C++11.
const size_t kTooBigAllocSize = INT_MAX;
// Detect runtime TCMalloc bypasses.
bool IsTcMallocBypassed() {
#if defined(OS_LINUX) || defined(OS_CHROMEOS)
// This should detect a TCMalloc bypass from Valgrind.
char* g_slice = getenv("G_SLICE");
if (g_slice && !strcmp(g_slice, "always-malloc"))
return true;
#endif
return false;
}
// Fake test that allow to know the state of TCMalloc by looking at bots.
TEST(SecurityTest, ALLOC_TEST(IsTCMallocDynamicallyBypassed)) {
printf("Malloc is dynamically bypassed: %s\n",
IsTcMallocBypassed() ? "yes." : "no.");
}
TEST(SecurityTest, ALLOC_TEST(MemoryAllocationRestrictionsMalloc)) {
if (!IsTcMallocBypassed()) {
scoped_ptr<char, base::FreeDeleter>
ptr(static_cast<char*>(malloc(kTooBigAllocSize)));
ASSERT_TRUE(ptr == NULL);
}
}
TEST(SecurityTest, ALLOC_TEST(MemoryAllocationRestrictionsCalloc)) {
if (!IsTcMallocBypassed()) {
scoped_ptr<char, base::FreeDeleter>
ptr(static_cast<char*>(calloc(kTooBigAllocSize, 1)));
ASSERT_TRUE(ptr == NULL);
}
}
TEST(SecurityTest, ALLOC_TEST(MemoryAllocationRestrictionsRealloc)) {
if (!IsTcMallocBypassed()) {
char* orig_ptr = static_cast<char*>(malloc(1));
ASSERT_TRUE(orig_ptr != NULL);
scoped_ptr<char, base::FreeDeleter>
ptr(static_cast<char*>(realloc(orig_ptr, kTooBigAllocSize)));
ASSERT_TRUE(ptr == NULL);
// If realloc() did not succeed, we need to free orig_ptr.
free(orig_ptr);
}
}
typedef struct {
char large_array[kTooBigAllocSize];
} VeryLargeStruct;
TEST(SecurityTest, ALLOC_TEST(MemoryAllocationRestrictionsNew)) {
if (!IsTcMallocBypassed()) {
scoped_ptr<VeryLargeStruct> ptr(new (nothrow) VeryLargeStruct);
ASSERT_TRUE(ptr == NULL);
}
}
TEST(SecurityTest, ALLOC_TEST(MemoryAllocationRestrictionsNewArray)) {
if (!IsTcMallocBypassed()) {
scoped_ptr<char[]> ptr(new (nothrow) char[kTooBigAllocSize]);
ASSERT_TRUE(ptr == NULL);
}
}
// The tests bellow check for overflows in new[] and calloc().
#if defined(OS_IOS) || defined(OS_WIN)
#define DISABLE_ON_IOS_AND_WIN(function) DISABLED_##function
#else
#define DISABLE_ON_IOS_AND_WIN(function) function
#endif
#if defined(ADDRESS_SANITIZER)
#define DISABLE_ON_ASAN(function) DISABLED_##function
#else
#define DISABLE_ON_ASAN(function) function
#endif
// There are platforms where these tests are known to fail. We would like to
// be able to easily check the status on the bots, but marking tests as
// FAILS_ is too clunky.
void OverflowTestsSoftExpectTrue(bool overflow_detected) {
if (!overflow_detected) {
#if defined(OS_LINUX) || defined(OS_ANDROID) || defined(OS_MACOSX)
// Sadly, on Linux, Android, and OSX we don't have a good story yet. Don't
// fail the test, but report.
printf("Platform has overflow: %s\n",
!overflow_detected ? "yes." : "no.");
#else
// Otherwise, fail the test. (Note: EXPECT are ok in subfunctions, ASSERT
// aren't).
EXPECT_TRUE(overflow_detected);
#endif
}
}
// This function acts as a compiler optimization barrier. We use it to
// prevent the compiler from making an expression a compile-time constant.
// We also use it so that the compiler doesn't discard certain return values
// as something we don't need (see the comment with calloc below).
template <typename Type>
Type HideValueFromCompiler(volatile Type value) {
return value;
}
// Test array[TooBig][X] and array[X][TooBig] allocations for int overflows.
// IOS doesn't honor nothrow, so disable the test there.
// Disable on Windows, we suspect some are failing because of it.
TEST(SecurityTest, DISABLE_ON_IOS_AND_WIN(NewOverflow)) {
const size_t kArraySize = 4096;
// We want something "dynamic" here, so that the compiler doesn't
// immediately reject crazy arrays.
const size_t kDynamicArraySize = HideValueFromCompiler(kArraySize);
// numeric_limits are still not constexpr until we switch to C++11, so we
// use an ugly cast.
const size_t kMaxSizeT = ~static_cast<size_t>(0);
ASSERT_EQ(numeric_limits<size_t>::max(), kMaxSizeT);
const size_t kArraySize2 = kMaxSizeT / kArraySize + 10;
const size_t kDynamicArraySize2 = HideValueFromCompiler(kArraySize2);
{
scoped_ptr<char[][kArraySize]> array_pointer(new (nothrow)
char[kDynamicArraySize2][kArraySize]);
OverflowTestsSoftExpectTrue(array_pointer == NULL);
}
{
scoped_ptr<char[][kArraySize2]> array_pointer(new (nothrow)
char[kDynamicArraySize][kArraySize2]);
OverflowTestsSoftExpectTrue(array_pointer == NULL);
}
}
// Test if calloc() can overflow. Disable on ASAN for now since the
// overflow seems present there.
TEST(SecurityTest, DISABLE_ON_ASAN(CallocOverflow)) {
const size_t kArraySize = 4096;
const size_t kMaxSizeT = numeric_limits<size_t>::max();
const size_t kArraySize2 = kMaxSizeT / kArraySize + 10;
{
scoped_ptr<char> array_pointer(
static_cast<char*>(calloc(kArraySize, kArraySize2)));
// We need the call to HideValueFromCompiler(): we have seen LLVM
// optimize away the call to calloc() entirely and assume
// the pointer to not be NULL.
EXPECT_TRUE(HideValueFromCompiler(array_pointer.get()) == NULL);
}
{
scoped_ptr<char> array_pointer(
static_cast<char*>(calloc(kArraySize2, kArraySize)));
// We need the call to HideValueFromCompiler(): we have seen LLVM
// optimize away the call to calloc() entirely and assume
// the pointer to not be NULL.
EXPECT_TRUE(HideValueFromCompiler(array_pointer.get()) == NULL);
}
}
} // namespace
|
