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1 //===-- interception_linux.cpp ----------------------------------*- C++ -*-===//
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2 //
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3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
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4 // See https://llvm.org/LICENSE.txt for license information.
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5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
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6 //
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7 //===----------------------------------------------------------------------===//
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8 //
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9 // This file is a part of AddressSanitizer, an address sanity checker.
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10 //
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11 // Windows-specific interception methods.
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12 //
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13 // This file is implementing several hooking techniques to intercept calls
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14 // to functions. The hooks are dynamically installed by modifying the assembly
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15 // code.
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16 //
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17 // The hooking techniques are making assumptions on the way the code is
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18 // generated and are safe under these assumptions.
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19 //
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20 // On 64-bit architecture, there is no direct 64-bit jump instruction. To allow
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21 // arbitrary branching on the whole memory space, the notion of trampoline
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22 // region is used. A trampoline region is a memory space withing 2G boundary
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23 // where it is safe to add custom assembly code to build 64-bit jumps.
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24 //
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25 // Hooking techniques
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26 // ==================
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27 //
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28 // 1) Detour
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29 //
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30 // The Detour hooking technique is assuming the presence of an header with
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31 // padding and an overridable 2-bytes nop instruction (mov edi, edi). The
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32 // nop instruction can safely be replaced by a 2-bytes jump without any need
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33 // to save the instruction. A jump to the target is encoded in the function
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34 // header and the nop instruction is replaced by a short jump to the header.
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35 //
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36 // head: 5 x nop head: jmp <hook>
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37 // func: mov edi, edi --> func: jmp short <head>
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38 // [...] real: [...]
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39 //
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40 // This technique is only implemented on 32-bit architecture.
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41 // Most of the time, Windows API are hookable with the detour technique.
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42 //
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43 // 2) Redirect Jump
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44 //
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45 // The redirect jump is applicable when the first instruction is a direct
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46 // jump. The instruction is replaced by jump to the hook.
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47 //
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48 // func: jmp <label> --> func: jmp <hook>
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49 //
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50 // On an 64-bit architecture, a trampoline is inserted.
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51 //
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52 // func: jmp <label> --> func: jmp <tramp>
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53 // [...]
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54 //
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55 // [trampoline]
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56 // tramp: jmp QWORD [addr]
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57 // addr: .bytes <hook>
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58 //
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59 // Note: <real> is equilavent to <label>.
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60 //
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61 // 3) HotPatch
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62 //
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63 // The HotPatch hooking is assuming the presence of an header with padding
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64 // and a first instruction with at least 2-bytes.
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65 //
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66 // The reason to enforce the 2-bytes limitation is to provide the minimal
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67 // space to encode a short jump. HotPatch technique is only rewriting one
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68 // instruction to avoid breaking a sequence of instructions containing a
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69 // branching target.
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70 //
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71 // Assumptions are enforced by MSVC compiler by using the /HOTPATCH flag.
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72 // see: https://msdn.microsoft.com/en-us/library/ms173507.aspx
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73 // Default padding length is 5 bytes in 32-bits and 6 bytes in 64-bits.
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74 //
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75 // head: 5 x nop head: jmp <hook>
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76 // func: <instr> --> func: jmp short <head>
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77 // [...] body: [...]
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78 //
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79 // [trampoline]
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80 // real: <instr>
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81 // jmp <body>
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82 //
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83 // On an 64-bit architecture:
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84 //
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85 // head: 6 x nop head: jmp QWORD [addr1]
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86 // func: <instr> --> func: jmp short <head>
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87 // [...] body: [...]
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88 //
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89 // [trampoline]
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90 // addr1: .bytes <hook>
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91 // real: <instr>
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92 // jmp QWORD [addr2]
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93 // addr2: .bytes <body>
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94 //
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95 // 4) Trampoline
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96 //
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97 // The Trampoline hooking technique is the most aggressive one. It is
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98 // assuming that there is a sequence of instructions that can be safely
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99 // replaced by a jump (enough room and no incoming branches).
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100 //
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101 // Unfortunately, these assumptions can't be safely presumed and code may
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102 // be broken after hooking.
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103 //
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104 // func: <instr> --> func: jmp <hook>
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105 // <instr>
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106 // [...] body: [...]
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107 //
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108 // [trampoline]
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109 // real: <instr>
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110 // <instr>
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111 // jmp <body>
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112 //
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113 // On an 64-bit architecture:
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114 //
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115 // func: <instr> --> func: jmp QWORD [addr1]
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116 // <instr>
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117 // [...] body: [...]
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118 //
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119 // [trampoline]
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120 // addr1: .bytes <hook>
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121 // real: <instr>
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122 // <instr>
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123 // jmp QWORD [addr2]
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124 // addr2: .bytes <body>
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125 //===----------------------------------------------------------------------===//
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126
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127 #include "interception.h"
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128
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129 #if SANITIZER_WINDOWS
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130 #include "sanitizer_common/sanitizer_platform.h"
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131 #define WIN32_LEAN_AND_MEAN
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132 #include <windows.h>
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133
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134 namespace __interception {
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135
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136 static const int kAddressLength = FIRST_32_SECOND_64(4, 8);
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137 static const int kJumpInstructionLength = 5;
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138 static const int kShortJumpInstructionLength = 2;
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139 static const int kIndirectJumpInstructionLength = 6;
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140 static const int kBranchLength =
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141 FIRST_32_SECOND_64(kJumpInstructionLength, kIndirectJumpInstructionLength);
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142 static const int kDirectBranchLength = kBranchLength + kAddressLength;
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143
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144 static void InterceptionFailed() {
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145 // Do we have a good way to abort with an error message here?
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146 __debugbreak();
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147 }
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148
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149 static bool DistanceIsWithin2Gig(uptr from, uptr target) {
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150 #if SANITIZER_WINDOWS64
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151 if (from < target)
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152 return target - from <= (uptr)0x7FFFFFFFU;
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153 else
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154 return from - target <= (uptr)0x80000000U;
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155 #else
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156 // In a 32-bit address space, the address calculation will wrap, so this check
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157 // is unnecessary.
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158 return true;
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159 #endif
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160 }
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161
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162 static uptr GetMmapGranularity() {
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163 SYSTEM_INFO si;
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164 GetSystemInfo(&si);
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165 return si.dwAllocationGranularity;
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166 }
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167
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168 static uptr RoundUpTo(uptr size, uptr boundary) {
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169 return (size + boundary - 1) & ~(boundary - 1);
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170 }
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171
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172 // FIXME: internal_str* and internal_mem* functions should be moved from the
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173 // ASan sources into interception/.
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174
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175 static size_t _strlen(const char *str) {
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176 const char* p = str;
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177 while (*p != '\0') ++p;
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178 return p - str;
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179 }
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180
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181 static char* _strchr(char* str, char c) {
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182 while (*str) {
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183 if (*str == c)
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184 return str;
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185 ++str;
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186 }
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187 return nullptr;
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188 }
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189
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190 static void _memset(void *p, int value, size_t sz) {
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191 for (size_t i = 0; i < sz; ++i)
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192 ((char*)p)[i] = (char)value;
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193 }
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194
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195 static void _memcpy(void *dst, void *src, size_t sz) {
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196 char *dst_c = (char*)dst,
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197 *src_c = (char*)src;
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198 for (size_t i = 0; i < sz; ++i)
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199 dst_c[i] = src_c[i];
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200 }
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201
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202 static bool ChangeMemoryProtection(
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203 uptr address, uptr size, DWORD *old_protection) {
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204 return ::VirtualProtect((void*)address, size,
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205 PAGE_EXECUTE_READWRITE,
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206 old_protection) != FALSE;
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207 }
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208
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209 static bool RestoreMemoryProtection(
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210 uptr address, uptr size, DWORD old_protection) {
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211 DWORD unused;
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212 return ::VirtualProtect((void*)address, size,
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213 old_protection,
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214 &unused) != FALSE;
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215 }
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216
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217 static bool IsMemoryPadding(uptr address, uptr size) {
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218 u8* function = (u8*)address;
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219 for (size_t i = 0; i < size; ++i)
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220 if (function[i] != 0x90 && function[i] != 0xCC)
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221 return false;
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222 return true;
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223 }
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224
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225 static const u8 kHintNop8Bytes[] = {
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226 0x0F, 0x1F, 0x84, 0x00, 0x00, 0x00, 0x00, 0x00
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227 };
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228
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229 template<class T>
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230 static bool FunctionHasPrefix(uptr address, const T &pattern) {
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231 u8* function = (u8*)address - sizeof(pattern);
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232 for (size_t i = 0; i < sizeof(pattern); ++i)
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233 if (function[i] != pattern[i])
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234 return false;
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235 return true;
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236 }
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237
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238 static bool FunctionHasPadding(uptr address, uptr size) {
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239 if (IsMemoryPadding(address - size, size))
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240 return true;
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241 if (size <= sizeof(kHintNop8Bytes) &&
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242 FunctionHasPrefix(address, kHintNop8Bytes))
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243 return true;
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244 return false;
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245 }
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246
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247 static void WritePadding(uptr from, uptr size) {
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248 _memset((void*)from, 0xCC, (size_t)size);
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249 }
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250
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251 static void WriteJumpInstruction(uptr from, uptr target) {
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252 if (!DistanceIsWithin2Gig(from + kJumpInstructionLength, target))
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253 InterceptionFailed();
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254 ptrdiff_t offset = target - from - kJumpInstructionLength;
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255 *(u8*)from = 0xE9;
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256 *(u32*)(from + 1) = offset;
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257 }
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258
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259 static void WriteShortJumpInstruction(uptr from, uptr target) {
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260 sptr offset = target - from - kShortJumpInstructionLength;
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261 if (offset < -128 || offset > 127)
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262 InterceptionFailed();
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263 *(u8*)from = 0xEB;
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264 *(u8*)(from + 1) = (u8)offset;
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265 }
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266
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267 #if SANITIZER_WINDOWS64
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268 static void WriteIndirectJumpInstruction(uptr from, uptr indirect_target) {
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269 // jmp [rip + <offset>] = FF 25 <offset> where <offset> is a relative
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270 // offset.
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271 // The offset is the distance from then end of the jump instruction to the
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272 // memory location containing the targeted address. The displacement is still
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273 // 32-bit in x64, so indirect_target must be located within +/- 2GB range.
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274 int offset = indirect_target - from - kIndirectJumpInstructionLength;
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275 if (!DistanceIsWithin2Gig(from + kIndirectJumpInstructionLength,
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276 indirect_target)) {
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277 InterceptionFailed();
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278 }
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279 *(u16*)from = 0x25FF;
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280 *(u32*)(from + 2) = offset;
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281 }
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282 #endif
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283
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284 static void WriteBranch(
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285 uptr from, uptr indirect_target, uptr target) {
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286 #if SANITIZER_WINDOWS64
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287 WriteIndirectJumpInstruction(from, indirect_target);
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288 *(u64*)indirect_target = target;
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289 #else
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290 (void)indirect_target;
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291 WriteJumpInstruction(from, target);
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292 #endif
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293 }
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294
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295 static void WriteDirectBranch(uptr from, uptr target) {
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296 #if SANITIZER_WINDOWS64
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297 // Emit an indirect jump through immediately following bytes:
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298 // jmp [rip + kBranchLength]
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299 // .quad <target>
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300 WriteBranch(from, from + kBranchLength, target);
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301 #else
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302 WriteJumpInstruction(from, target);
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303 #endif
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304 }
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305
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306 struct TrampolineMemoryRegion {
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307 uptr content;
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308 uptr allocated_size;
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309 uptr max_size;
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310 };
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311
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312 static const uptr kTrampolineScanLimitRange = 1 << 31; // 2 gig
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313 static const int kMaxTrampolineRegion = 1024;
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314 static TrampolineMemoryRegion TrampolineRegions[kMaxTrampolineRegion];
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315
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316 static void *AllocateTrampolineRegion(uptr image_address, size_t granularity) {
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317 #if SANITIZER_WINDOWS64
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318 uptr address = image_address;
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319 uptr scanned = 0;
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320 while (scanned < kTrampolineScanLimitRange) {
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321 MEMORY_BASIC_INFORMATION info;
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322 if (!::VirtualQuery((void*)address, &info, sizeof(info)))
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323 return nullptr;
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324
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325 // Check whether a region can be allocated at |address|.
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326 if (info.State == MEM_FREE && info.RegionSize >= granularity) {
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327 void *page = ::VirtualAlloc((void*)RoundUpTo(address, granularity),
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328 granularity,
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329 MEM_RESERVE | MEM_COMMIT,
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330 PAGE_EXECUTE_READWRITE);
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331 return page;
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332 }
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333
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334 // Move to the next region.
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335 address = (uptr)info.BaseAddress + info.RegionSize;
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336 scanned += info.RegionSize;
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337 }
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338 return nullptr;
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339 #else
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340 return ::VirtualAlloc(nullptr,
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341 granularity,
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342 MEM_RESERVE | MEM_COMMIT,
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343 PAGE_EXECUTE_READWRITE);
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344 #endif
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345 }
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346
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347 // Used by unittests to release mapped memory space.
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348 void TestOnlyReleaseTrampolineRegions() {
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349 for (size_t bucket = 0; bucket < kMaxTrampolineRegion; ++bucket) {
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350 TrampolineMemoryRegion *current = &TrampolineRegions[bucket];
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351 if (current->content == 0)
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352 return;
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353 ::VirtualFree((void*)current->content, 0, MEM_RELEASE);
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354 current->content = 0;
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355 }
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356 }
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357
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358 static uptr AllocateMemoryForTrampoline(uptr image_address, size_t size) {
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359 // Find a region within 2G with enough space to allocate |size| bytes.
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360 TrampolineMemoryRegion *region = nullptr;
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361 for (size_t bucket = 0; bucket < kMaxTrampolineRegion; ++bucket) {
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362 TrampolineMemoryRegion* current = &TrampolineRegions[bucket];
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363 if (current->content == 0) {
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364 // No valid region found, allocate a new region.
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365 size_t bucket_size = GetMmapGranularity();
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366 void *content = AllocateTrampolineRegion(image_address, bucket_size);
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367 if (content == nullptr)
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368 return 0U;
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369
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370 current->content = (uptr)content;
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371 current->allocated_size = 0;
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372 current->max_size = bucket_size;
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373 region = current;
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374 break;
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375 } else if (current->max_size - current->allocated_size > size) {
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376 #if SANITIZER_WINDOWS64
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377 // In 64-bits, the memory space must be allocated within 2G boundary.
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378 uptr next_address = current->content + current->allocated_size;
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379 if (next_address < image_address ||
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380 next_address - image_address >= 0x7FFF0000)
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381 continue;
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382 #endif
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383 // The space can be allocated in the current region.
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384 region = current;
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385 break;
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386 }
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387 }
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388
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389 // Failed to find a region.
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390 if (region == nullptr)
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391 return 0U;
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392
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393 // Allocate the space in the current region.
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394 uptr allocated_space = region->content + region->allocated_size;
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395 region->allocated_size += size;
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396 WritePadding(allocated_space, size);
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397
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398 return allocated_space;
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399 }
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400
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401 // Returns 0 on error.
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402 static size_t GetInstructionSize(uptr address, size_t* rel_offset = nullptr) {
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403 switch (*(u64*)address) {
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404 case 0x90909090909006EB: // stub: jmp over 6 x nop.
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405 return 8;
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406 }
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407
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408 switch (*(u8*)address) {
|
|
|
409 case 0x90: // 90 : nop
|
|
|
410 return 1;
|
|
|
411
|
|
|
412 case 0x50: // push eax / rax
|
|
|
413 case 0x51: // push ecx / rcx
|
|
|
414 case 0x52: // push edx / rdx
|
|
|
415 case 0x53: // push ebx / rbx
|
|
|
416 case 0x54: // push esp / rsp
|
|
|
417 case 0x55: // push ebp / rbp
|
|
|
418 case 0x56: // push esi / rsi
|
|
|
419 case 0x57: // push edi / rdi
|
|
|
420 case 0x5D: // pop ebp / rbp
|
|
|
421 return 1;
|
|
|
422
|
|
|
423 case 0x6A: // 6A XX = push XX
|
|
|
424 return 2;
|
|
|
425
|
|
|
426 case 0xb8: // b8 XX XX XX XX : mov eax, XX XX XX XX
|
|
|
427 case 0xB9: // b9 XX XX XX XX : mov ecx, XX XX XX XX
|
|
|
428 return 5;
|
|
|
429
|
|
|
430 // Cannot overwrite control-instruction. Return 0 to indicate failure.
|
|
|
431 case 0xE9: // E9 XX XX XX XX : jmp <label>
|
|
|
432 case 0xE8: // E8 XX XX XX XX : call <func>
|
|
|
433 case 0xC3: // C3 : ret
|
|
|
434 case 0xEB: // EB XX : jmp XX (short jump)
|
|
|
435 case 0x70: // 7Y YY : jy XX (short conditional jump)
|
|
|
436 case 0x71:
|
|
|
437 case 0x72:
|
|
|
438 case 0x73:
|
|
|
439 case 0x74:
|
|
|
440 case 0x75:
|
|
|
441 case 0x76:
|
|
|
442 case 0x77:
|
|
|
443 case 0x78:
|
|
|
444 case 0x79:
|
|
|
445 case 0x7A:
|
|
|
446 case 0x7B:
|
|
|
447 case 0x7C:
|
|
|
448 case 0x7D:
|
|
|
449 case 0x7E:
|
|
|
450 case 0x7F:
|
|
|
451 return 0;
|
|
|
452 }
|
|
|
453
|
|
|
454 switch (*(u16*)(address)) {
|
|
|
455 case 0x018A: // 8A 01 : mov al, byte ptr [ecx]
|
|
|
456 case 0xFF8B: // 8B FF : mov edi, edi
|
|
|
457 case 0xEC8B: // 8B EC : mov ebp, esp
|
|
|
458 case 0xc889: // 89 C8 : mov eax, ecx
|
|
|
459 case 0xC18B: // 8B C1 : mov eax, ecx
|
|
|
460 case 0xC033: // 33 C0 : xor eax, eax
|
|
|
461 case 0xC933: // 33 C9 : xor ecx, ecx
|
|
|
462 case 0xD233: // 33 D2 : xor edx, edx
|
|
|
463 return 2;
|
|
|
464
|
|
|
465 // Cannot overwrite control-instruction. Return 0 to indicate failure.
|
|
|
466 case 0x25FF: // FF 25 XX XX XX XX : jmp [XXXXXXXX]
|
|
|
467 return 0;
|
|
|
468 }
|
|
|
469
|
|
|
470 switch (0x00FFFFFF & *(u32*)address) {
|
|
|
471 case 0x24A48D: // 8D A4 24 XX XX XX XX : lea esp, [esp + XX XX XX XX]
|
|
|
472 return 7;
|
|
|
473 }
|
|
|
474
|
|
|
475 #if SANITIZER_WINDOWS64
|
|
|
476 switch (*(u8*)address) {
|
|
|
477 case 0xA1: // A1 XX XX XX XX XX XX XX XX :
|
|
|
478 // movabs eax, dword ptr ds:[XXXXXXXX]
|
|
|
479 return 9;
|
|
|
480 }
|
|
|
481
|
|
|
482 switch (*(u16*)address) {
|
|
|
483 case 0x5040: // push rax
|
|
|
484 case 0x5140: // push rcx
|
|
|
485 case 0x5240: // push rdx
|
|
|
486 case 0x5340: // push rbx
|
|
|
487 case 0x5440: // push rsp
|
|
|
488 case 0x5540: // push rbp
|
|
|
489 case 0x5640: // push rsi
|
|
|
490 case 0x5740: // push rdi
|
|
|
491 case 0x5441: // push r12
|
|
|
492 case 0x5541: // push r13
|
|
|
493 case 0x5641: // push r14
|
|
|
494 case 0x5741: // push r15
|
|
|
495 case 0x9066: // Two-byte NOP
|
|
|
496 return 2;
|
|
|
497
|
|
|
498 case 0x058B: // 8B 05 XX XX XX XX : mov eax, dword ptr [XX XX XX XX]
|
|
|
499 if (rel_offset)
|
|
|
500 *rel_offset = 2;
|
|
|
501 return 6;
|
|
|
502 }
|
|
|
503
|
|
|
504 switch (0x00FFFFFF & *(u32*)address) {
|
|
|
505 case 0xe58948: // 48 8b c4 : mov rbp, rsp
|
|
|
506 case 0xc18b48: // 48 8b c1 : mov rax, rcx
|
|
|
507 case 0xc48b48: // 48 8b c4 : mov rax, rsp
|
|
|
508 case 0xd9f748: // 48 f7 d9 : neg rcx
|
|
|
509 case 0xd12b48: // 48 2b d1 : sub rdx, rcx
|
|
|
510 case 0x07c1f6: // f6 c1 07 : test cl, 0x7
|
|
|
511 case 0xc98548: // 48 85 C9 : test rcx, rcx
|
|
|
512 case 0xc0854d: // 4d 85 c0 : test r8, r8
|
|
|
513 case 0xc2b60f: // 0f b6 c2 : movzx eax, dl
|
|
|
514 case 0xc03345: // 45 33 c0 : xor r8d, r8d
|
|
|
515 case 0xc93345: // 45 33 c9 : xor r9d, r9d
|
|
|
516 case 0xdb3345: // 45 33 DB : xor r11d, r11d
|
|
|
517 case 0xd98b4c: // 4c 8b d9 : mov r11, rcx
|
|
|
518 case 0xd28b4c: // 4c 8b d2 : mov r10, rdx
|
|
|
519 case 0xc98b4c: // 4C 8B C9 : mov r9, rcx
|
|
|
520 case 0xc18b4c: // 4C 8B C1 : mov r8, rcx
|
|
|
521 case 0xd2b60f: // 0f b6 d2 : movzx edx, dl
|
|
|
522 case 0xca2b48: // 48 2b ca : sub rcx, rdx
|
|
|
523 case 0x10b70f: // 0f b7 10 : movzx edx, WORD PTR [rax]
|
|
|
524 case 0xc00b4d: // 3d 0b c0 : or r8, r8
|
|
|
525 case 0xd18b48: // 48 8b d1 : mov rdx, rcx
|
|
|
526 case 0xdc8b4c: // 4c 8b dc : mov r11, rsp
|
|
|
527 case 0xd18b4c: // 4c 8b d1 : mov r10, rcx
|
|
|
528 case 0xE0E483: // 83 E4 E0 : and esp, 0xFFFFFFE0
|
|
|
529 return 3;
|
|
|
530
|
|
|
531 case 0xec8348: // 48 83 ec XX : sub rsp, XX
|
|
|
532 case 0xf88349: // 49 83 f8 XX : cmp r8, XX
|
|
|
533 case 0x588948: // 48 89 58 XX : mov QWORD PTR[rax + XX], rbx
|
|
|
534 return 4;
|
|
|
535
|
|
|
536 case 0xec8148: // 48 81 EC XX XX XX XX : sub rsp, XXXXXXXX
|
|
|
537 return 7;
|
|
|
538
|
|
|
539 case 0x058b48: // 48 8b 05 XX XX XX XX :
|
|
|
540 // mov rax, QWORD PTR [rip + XXXXXXXX]
|
|
|
541 case 0x25ff48: // 48 ff 25 XX XX XX XX :
|
|
|
542 // rex.W jmp QWORD PTR [rip + XXXXXXXX]
|
|
|
543
|
|
|
544 // Instructions having offset relative to 'rip' need offset adjustment.
|
|
|
545 if (rel_offset)
|
|
|
546 *rel_offset = 3;
|
|
|
547 return 7;
|
|
|
548
|
|
|
549 case 0x2444c7: // C7 44 24 XX YY YY YY YY
|
|
|
550 // mov dword ptr [rsp + XX], YYYYYYYY
|
|
|
551 return 8;
|
|
|
552 }
|
|
|
553
|
|
|
554 switch (*(u32*)(address)) {
|
|
|
555 case 0x24448b48: // 48 8b 44 24 XX : mov rax, QWORD ptr [rsp + XX]
|
|
|
556 case 0x246c8948: // 48 89 6C 24 XX : mov QWORD ptr [rsp + XX], rbp
|
|
|
557 case 0x245c8948: // 48 89 5c 24 XX : mov QWORD PTR [rsp + XX], rbx
|
|
|
558 case 0x24748948: // 48 89 74 24 XX : mov QWORD PTR [rsp + XX], rsi
|
|
|
559 case 0x244C8948: // 48 89 4C 24 XX : mov QWORD PTR [rsp + XX], rcx
|
|
|
560 case 0x24548948: // 48 89 54 24 XX : mov QWORD PTR [rsp + XX], rdx
|
|
|
561 case 0x244c894c: // 4c 89 4c 24 XX : mov QWORD PTR [rsp + XX], r9
|
|
|
562 case 0x2444894c: // 4c 89 44 24 XX : mov QWORD PTR [rsp + XX], r8
|
|
|
563 return 5;
|
|
|
564 case 0x24648348: // 48 83 64 24 XX : and QWORD PTR [rsp + XX], YY
|
|
|
565 return 6;
|
|
|
566 }
|
|
|
567
|
|
|
568 #else
|
|
|
569
|
|
|
570 switch (*(u8*)address) {
|
|
|
571 case 0xA1: // A1 XX XX XX XX : mov eax, dword ptr ds:[XXXXXXXX]
|
|
|
572 return 5;
|
|
|
573 }
|
|
|
574 switch (*(u16*)address) {
|
|
|
575 case 0x458B: // 8B 45 XX : mov eax, dword ptr [ebp + XX]
|
|
|
576 case 0x5D8B: // 8B 5D XX : mov ebx, dword ptr [ebp + XX]
|
|
|
577 case 0x7D8B: // 8B 7D XX : mov edi, dword ptr [ebp + XX]
|
|
|
578 case 0xEC83: // 83 EC XX : sub esp, XX
|
|
|
579 case 0x75FF: // FF 75 XX : push dword ptr [ebp + XX]
|
|
|
580 return 3;
|
|
|
581 case 0xC1F7: // F7 C1 XX YY ZZ WW : test ecx, WWZZYYXX
|
|
|
582 case 0x25FF: // FF 25 XX YY ZZ WW : jmp dword ptr ds:[WWZZYYXX]
|
|
|
583 return 6;
|
|
|
584 case 0x3D83: // 83 3D XX YY ZZ WW TT : cmp TT, WWZZYYXX
|
|
|
585 return 7;
|
|
|
586 case 0x7D83: // 83 7D XX YY : cmp dword ptr [ebp + XX], YY
|
|
|
587 return 4;
|
|
|
588 }
|
|
|
589
|
|
|
590 switch (0x00FFFFFF & *(u32*)address) {
|
|
|
591 case 0x24448A: // 8A 44 24 XX : mov eal, dword ptr [esp + XX]
|
|
|
592 case 0x24448B: // 8B 44 24 XX : mov eax, dword ptr [esp + XX]
|
|
|
593 case 0x244C8B: // 8B 4C 24 XX : mov ecx, dword ptr [esp + XX]
|
|
|
594 case 0x24548B: // 8B 54 24 XX : mov edx, dword ptr [esp + XX]
|
|
|
595 case 0x24748B: // 8B 74 24 XX : mov esi, dword ptr [esp + XX]
|
|
|
596 case 0x247C8B: // 8B 7C 24 XX : mov edi, dword ptr [esp + XX]
|
|
|
597 return 4;
|
|
|
598 }
|
|
|
599
|
|
|
600 switch (*(u32*)address) {
|
|
|
601 case 0x2444B60F: // 0F B6 44 24 XX : movzx eax, byte ptr [esp + XX]
|
|
|
602 return 5;
|
|
|
603 }
|
|
|
604 #endif
|
|
|
605
|
|
|
606 // Unknown instruction!
|
|
|
607 // FIXME: Unknown instruction failures might happen when we add a new
|
|
|
608 // interceptor or a new compiler version. In either case, they should result
|
|
|
609 // in visible and readable error messages. However, merely calling abort()
|
|
|
610 // leads to an infinite recursion in CheckFailed.
|
|
|
611 InterceptionFailed();
|
|
|
612 return 0;
|
|
|
613 }
|
|
|
614
|
|
|
615 // Returns 0 on error.
|
|
|
616 static size_t RoundUpToInstrBoundary(size_t size, uptr address) {
|
|
|
617 size_t cursor = 0;
|
|
|
618 while (cursor < size) {
|
|
|
619 size_t instruction_size = GetInstructionSize(address + cursor);
|
|
|
620 if (!instruction_size)
|
|
|
621 return 0;
|
|
|
622 cursor += instruction_size;
|
|
|
623 }
|
|
|
624 return cursor;
|
|
|
625 }
|
|
|
626
|
|
|
627 static bool CopyInstructions(uptr to, uptr from, size_t size) {
|
|
|
628 size_t cursor = 0;
|
|
|
629 while (cursor != size) {
|
|
|
630 size_t rel_offset = 0;
|
|
|
631 size_t instruction_size = GetInstructionSize(from + cursor, &rel_offset);
|
|
|
632 _memcpy((void*)(to + cursor), (void*)(from + cursor),
|
|
|
633 (size_t)instruction_size);
|
|
|
634 if (rel_offset) {
|
|
|
635 uptr delta = to - from;
|
|
|
636 uptr relocated_offset = *(u32*)(to + cursor + rel_offset) - delta;
|
|
|
637 #if SANITIZER_WINDOWS64
|
|
|
638 if (relocated_offset + 0x80000000U >= 0xFFFFFFFFU)
|
|
|
639 return false;
|
|
|
640 #endif
|
|
|
641 *(u32*)(to + cursor + rel_offset) = relocated_offset;
|
|
|
642 }
|
|
|
643 cursor += instruction_size;
|
|
|
644 }
|
|
|
645 return true;
|
|
|
646 }
|
|
|
647
|
|
|
648
|
|
|
649 #if !SANITIZER_WINDOWS64
|
|
|
650 bool OverrideFunctionWithDetour(
|
|
|
651 uptr old_func, uptr new_func, uptr *orig_old_func) {
|
|
|
652 const int kDetourHeaderLen = 5;
|
|
|
653 const u16 kDetourInstruction = 0xFF8B;
|
|
|
654
|
|
|
655 uptr header = (uptr)old_func - kDetourHeaderLen;
|
|
|
656 uptr patch_length = kDetourHeaderLen + kShortJumpInstructionLength;
|
|
|
657
|
|
|
658 // Validate that the function is hookable.
|
|
|
659 if (*(u16*)old_func != kDetourInstruction ||
|
|
|
660 !IsMemoryPadding(header, kDetourHeaderLen))
|
|
|
661 return false;
|
|
|
662
|
|
|
663 // Change memory protection to writable.
|
|
|
664 DWORD protection = 0;
|
|
|
665 if (!ChangeMemoryProtection(header, patch_length, &protection))
|
|
|
666 return false;
|
|
|
667
|
|
|
668 // Write a relative jump to the redirected function.
|
|
|
669 WriteJumpInstruction(header, new_func);
|
|
|
670
|
|
|
671 // Write the short jump to the function prefix.
|
|
|
672 WriteShortJumpInstruction(old_func, header);
|
|
|
673
|
|
|
674 // Restore previous memory protection.
|
|
|
675 if (!RestoreMemoryProtection(header, patch_length, protection))
|
|
|
676 return false;
|
|
|
677
|
|
|
678 if (orig_old_func)
|
|
|
679 *orig_old_func = old_func + kShortJumpInstructionLength;
|
|
|
680
|
|
|
681 return true;
|
|
|
682 }
|
|
|
683 #endif
|
|
|
684
|
|
|
685 bool OverrideFunctionWithRedirectJump(
|
|
|
686 uptr old_func, uptr new_func, uptr *orig_old_func) {
|
|
|
687 // Check whether the first instruction is a relative jump.
|
|
|
688 if (*(u8*)old_func != 0xE9)
|
|
|
689 return false;
|
|
|
690
|
|
|
691 if (orig_old_func) {
|
|
|
692 uptr relative_offset = *(u32*)(old_func + 1);
|
|
|
693 uptr absolute_target = old_func + relative_offset + kJumpInstructionLength;
|
|
|
694 *orig_old_func = absolute_target;
|
|
|
695 }
|
|
|
696
|
|
|
697 #if SANITIZER_WINDOWS64
|
|
|
698 // If needed, get memory space for a trampoline jump.
|
|
|
699 uptr trampoline = AllocateMemoryForTrampoline(old_func, kDirectBranchLength);
|
|
|
700 if (!trampoline)
|
|
|
701 return false;
|
|
|
702 WriteDirectBranch(trampoline, new_func);
|
|
|
703 #endif
|
|
|
704
|
|
|
705 // Change memory protection to writable.
|
|
|
706 DWORD protection = 0;
|
|
|
707 if (!ChangeMemoryProtection(old_func, kJumpInstructionLength, &protection))
|
|
|
708 return false;
|
|
|
709
|
|
|
710 // Write a relative jump to the redirected function.
|
|
|
711 WriteJumpInstruction(old_func, FIRST_32_SECOND_64(new_func, trampoline));
|
|
|
712
|
|
|
713 // Restore previous memory protection.
|
|
|
714 if (!RestoreMemoryProtection(old_func, kJumpInstructionLength, protection))
|
|
|
715 return false;
|
|
|
716
|
|
|
717 return true;
|
|
|
718 }
|
|
|
719
|
|
|
720 bool OverrideFunctionWithHotPatch(
|
|
|
721 uptr old_func, uptr new_func, uptr *orig_old_func) {
|
|
|
722 const int kHotPatchHeaderLen = kBranchLength;
|
|
|
723
|
|
|
724 uptr header = (uptr)old_func - kHotPatchHeaderLen;
|
|
|
725 uptr patch_length = kHotPatchHeaderLen + kShortJumpInstructionLength;
|
|
|
726
|
|
|
727 // Validate that the function is hot patchable.
|
|
|
728 size_t instruction_size = GetInstructionSize(old_func);
|
|
|
729 if (instruction_size < kShortJumpInstructionLength ||
|
|
|
730 !FunctionHasPadding(old_func, kHotPatchHeaderLen))
|
|
|
731 return false;
|
|
|
732
|
|
|
733 if (orig_old_func) {
|
|
|
734 // Put the needed instructions into the trampoline bytes.
|
|
|
735 uptr trampoline_length = instruction_size + kDirectBranchLength;
|
|
|
736 uptr trampoline = AllocateMemoryForTrampoline(old_func, trampoline_length);
|
|
|
737 if (!trampoline)
|
|
|
738 return false;
|
|
|
739 if (!CopyInstructions(trampoline, old_func, instruction_size))
|
|
|
740 return false;
|
|
|
741 WriteDirectBranch(trampoline + instruction_size,
|
|
|
742 old_func + instruction_size);
|
|
|
743 *orig_old_func = trampoline;
|
|
|
744 }
|
|
|
745
|
|
|
746 // If needed, get memory space for indirect address.
|
|
|
747 uptr indirect_address = 0;
|
|
|
748 #if SANITIZER_WINDOWS64
|
|
|
749 indirect_address = AllocateMemoryForTrampoline(old_func, kAddressLength);
|
|
|
750 if (!indirect_address)
|
|
|
751 return false;
|
|
|
752 #endif
|
|
|
753
|
|
|
754 // Change memory protection to writable.
|
|
|
755 DWORD protection = 0;
|
|
|
756 if (!ChangeMemoryProtection(header, patch_length, &protection))
|
|
|
757 return false;
|
|
|
758
|
|
|
759 // Write jumps to the redirected function.
|
|
|
760 WriteBranch(header, indirect_address, new_func);
|
|
|
761 WriteShortJumpInstruction(old_func, header);
|
|
|
762
|
|
|
763 // Restore previous memory protection.
|
|
|
764 if (!RestoreMemoryProtection(header, patch_length, protection))
|
|
|
765 return false;
|
|
|
766
|
|
|
767 return true;
|
|
|
768 }
|
|
|
769
|
|
|
770 bool OverrideFunctionWithTrampoline(
|
|
|
771 uptr old_func, uptr new_func, uptr *orig_old_func) {
|
|
|
772
|
|
|
773 size_t instructions_length = kBranchLength;
|
|
|
774 size_t padding_length = 0;
|
|
|
775 uptr indirect_address = 0;
|
|
|
776
|
|
|
777 if (orig_old_func) {
|
|
|
778 // Find out the number of bytes of the instructions we need to copy
|
|
|
779 // to the trampoline.
|
|
|
780 instructions_length = RoundUpToInstrBoundary(kBranchLength, old_func);
|
|
|
781 if (!instructions_length)
|
|
|
782 return false;
|
|
|
783
|
|
|
784 // Put the needed instructions into the trampoline bytes.
|
|
|
785 uptr trampoline_length = instructions_length + kDirectBranchLength;
|
|
|
786 uptr trampoline = AllocateMemoryForTrampoline(old_func, trampoline_length);
|
|
|
787 if (!trampoline)
|
|
|
788 return false;
|
|
|
789 if (!CopyInstructions(trampoline, old_func, instructions_length))
|
|
|
790 return false;
|
|
|
791 WriteDirectBranch(trampoline + instructions_length,
|
|
|
792 old_func + instructions_length);
|
|
|
793 *orig_old_func = trampoline;
|
|
|
794 }
|
|
|
795
|
|
|
796 #if SANITIZER_WINDOWS64
|
|
|
797 // Check if the targeted address can be encoded in the function padding.
|
|
|
798 // Otherwise, allocate it in the trampoline region.
|
|
|
799 if (IsMemoryPadding(old_func - kAddressLength, kAddressLength)) {
|
|
|
800 indirect_address = old_func - kAddressLength;
|
|
|
801 padding_length = kAddressLength;
|
|
|
802 } else {
|
|
|
803 indirect_address = AllocateMemoryForTrampoline(old_func, kAddressLength);
|
|
|
804 if (!indirect_address)
|
|
|
805 return false;
|
|
|
806 }
|
|
|
807 #endif
|
|
|
808
|
|
|
809 // Change memory protection to writable.
|
|
|
810 uptr patch_address = old_func - padding_length;
|
|
|
811 uptr patch_length = instructions_length + padding_length;
|
|
|
812 DWORD protection = 0;
|
|
|
813 if (!ChangeMemoryProtection(patch_address, patch_length, &protection))
|
|
|
814 return false;
|
|
|
815
|
|
|
816 // Patch the original function.
|
|
|
817 WriteBranch(old_func, indirect_address, new_func);
|
|
|
818
|
|
|
819 // Restore previous memory protection.
|
|
|
820 if (!RestoreMemoryProtection(patch_address, patch_length, protection))
|
|
|
821 return false;
|
|
|
822
|
|
|
823 return true;
|
|
|
824 }
|
|
|
825
|
|
|
826 bool OverrideFunction(
|
|
|
827 uptr old_func, uptr new_func, uptr *orig_old_func) {
|
|
|
828 #if !SANITIZER_WINDOWS64
|
|
|
829 if (OverrideFunctionWithDetour(old_func, new_func, orig_old_func))
|
|
|
830 return true;
|
|
|
831 #endif
|
|
|
832 if (OverrideFunctionWithRedirectJump(old_func, new_func, orig_old_func))
|
|
|
833 return true;
|
|
|
834 if (OverrideFunctionWithHotPatch(old_func, new_func, orig_old_func))
|
|
|
835 return true;
|
|
|
836 if (OverrideFunctionWithTrampoline(old_func, new_func, orig_old_func))
|
|
|
837 return true;
|
|
|
838 return false;
|
|
|
839 }
|
|
|
840
|
|
|
841 static void **InterestingDLLsAvailable() {
|
|
|
842 static const char *InterestingDLLs[] = {
|
|
|
843 "kernel32.dll",
|
|
|
844 "msvcr100.dll", // VS2010
|
|
|
845 "msvcr110.dll", // VS2012
|
|
|
846 "msvcr120.dll", // VS2013
|
|
|
847 "vcruntime140.dll", // VS2015
|
|
|
848 "ucrtbase.dll", // Universal CRT
|
|
|
849 // NTDLL should go last as it exports some functions that we should
|
|
|
850 // override in the CRT [presumably only used internally].
|
|
|
851 "ntdll.dll", NULL};
|
|
|
852 static void *result[ARRAY_SIZE(InterestingDLLs)] = { 0 };
|
|
|
853 if (!result[0]) {
|
|
|
854 for (size_t i = 0, j = 0; InterestingDLLs[i]; ++i) {
|
|
|
855 if (HMODULE h = GetModuleHandleA(InterestingDLLs[i]))
|
|
|
856 result[j++] = (void *)h;
|
|
|
857 }
|
|
|
858 }
|
|
|
859 return &result[0];
|
|
|
860 }
|
|
|
861
|
|
|
862 namespace {
|
|
|
863 // Utility for reading loaded PE images.
|
|
|
864 template <typename T> class RVAPtr {
|
|
|
865 public:
|
|
|
866 RVAPtr(void *module, uptr rva)
|
|
|
867 : ptr_(reinterpret_cast<T *>(reinterpret_cast<char *>(module) + rva)) {}
|
|
|
868 operator T *() { return ptr_; }
|
|
|
869 T *operator->() { return ptr_; }
|
|
|
870 T *operator++() { return ++ptr_; }
|
|
|
871
|
|
|
872 private:
|
|
|
873 T *ptr_;
|
|
|
874 };
|
|
|
875 } // namespace
|
|
|
876
|
|
|
877 // Internal implementation of GetProcAddress. At least since Windows 8,
|
|
|
878 // GetProcAddress appears to initialize DLLs before returning function pointers
|
|
|
879 // into them. This is problematic for the sanitizers, because they typically
|
|
|
880 // want to intercept malloc *before* MSVCRT initializes. Our internal
|
|
|
881 // implementation walks the export list manually without doing initialization.
|
|
|
882 uptr InternalGetProcAddress(void *module, const char *func_name) {
|
|
|
883 // Check that the module header is full and present.
|
|
|
884 RVAPtr<IMAGE_DOS_HEADER> dos_stub(module, 0);
|
|
|
885 RVAPtr<IMAGE_NT_HEADERS> headers(module, dos_stub->e_lfanew);
|
|
|
886 if (!module || dos_stub->e_magic != IMAGE_DOS_SIGNATURE || // "MZ"
|
|
|
887 headers->Signature != IMAGE_NT_SIGNATURE || // "PE\0\0"
|
|
|
888 headers->FileHeader.SizeOfOptionalHeader <
|
|
|
889 sizeof(IMAGE_OPTIONAL_HEADER)) {
|
|
|
890 return 0;
|
|
|
891 }
|
|
|
892
|
|
|
893 IMAGE_DATA_DIRECTORY *export_directory =
|
|
|
894 &headers->OptionalHeader.DataDirectory[IMAGE_DIRECTORY_ENTRY_EXPORT];
|
|
|
895 if (export_directory->Size == 0)
|
|
|
896 return 0;
|
|
|
897 RVAPtr<IMAGE_EXPORT_DIRECTORY> exports(module,
|
|
|
898 export_directory->VirtualAddress);
|
|
|
899 RVAPtr<DWORD> functions(module, exports->AddressOfFunctions);
|
|
|
900 RVAPtr<DWORD> names(module, exports->AddressOfNames);
|
|
|
901 RVAPtr<WORD> ordinals(module, exports->AddressOfNameOrdinals);
|
|
|
902
|
|
|
903 for (DWORD i = 0; i < exports->NumberOfNames; i++) {
|
|
|
904 RVAPtr<char> name(module, names[i]);
|
|
|
905 if (!strcmp(func_name, name)) {
|
|
|
906 DWORD index = ordinals[i];
|
|
|
907 RVAPtr<char> func(module, functions[index]);
|
|
|
908
|
|
|
909 // Handle forwarded functions.
|
|
|
910 DWORD offset = functions[index];
|
|
|
911 if (offset >= export_directory->VirtualAddress &&
|
|
|
912 offset < export_directory->VirtualAddress + export_directory->Size) {
|
|
|
913 // An entry for a forwarded function is a string with the following
|
|
|
914 // format: "<module> . <function_name>" that is stored into the
|
|
|
915 // exported directory.
|
|
|
916 char function_name[256];
|
|
|
917 size_t funtion_name_length = _strlen(func);
|
|
|
918 if (funtion_name_length >= sizeof(function_name) - 1)
|
|
|
919 InterceptionFailed();
|
|
|
920
|
|
|
921 _memcpy(function_name, func, funtion_name_length);
|
|
|
922 function_name[funtion_name_length] = '\0';
|
|
|
923 char* separator = _strchr(function_name, '.');
|
|
|
924 if (!separator)
|
|
|
925 InterceptionFailed();
|
|
|
926 *separator = '\0';
|
|
|
927
|
|
|
928 void* redirected_module = GetModuleHandleA(function_name);
|
|
|
929 if (!redirected_module)
|
|
|
930 InterceptionFailed();
|
|
|
931 return InternalGetProcAddress(redirected_module, separator + 1);
|
|
|
932 }
|
|
|
933
|
|
|
934 return (uptr)(char *)func;
|
|
|
935 }
|
|
|
936 }
|
|
|
937
|
|
|
938 return 0;
|
|
|
939 }
|
|
|
940
|
|
|
941 bool OverrideFunction(
|
|
|
942 const char *func_name, uptr new_func, uptr *orig_old_func) {
|
|
|
943 bool hooked = false;
|
|
|
944 void **DLLs = InterestingDLLsAvailable();
|
|
|
945 for (size_t i = 0; DLLs[i]; ++i) {
|
|
|
946 uptr func_addr = InternalGetProcAddress(DLLs[i], func_name);
|
|
|
947 if (func_addr &&
|
|
|
948 OverrideFunction(func_addr, new_func, orig_old_func)) {
|
|
|
949 hooked = true;
|
|
|
950 }
|
|
|
951 }
|
|
|
952 return hooked;
|
|
|
953 }
|
|
|
954
|
|
|
955 bool OverrideImportedFunction(const char *module_to_patch,
|
|
|
956 const char *imported_module,
|
|
|
957 const char *function_name, uptr new_function,
|
|
|
958 uptr *orig_old_func) {
|
|
|
959 HMODULE module = GetModuleHandleA(module_to_patch);
|
|
|
960 if (!module)
|
|
|
961 return false;
|
|
|
962
|
|
|
963 // Check that the module header is full and present.
|
|
|
964 RVAPtr<IMAGE_DOS_HEADER> dos_stub(module, 0);
|
|
|
965 RVAPtr<IMAGE_NT_HEADERS> headers(module, dos_stub->e_lfanew);
|
|
|
966 if (!module || dos_stub->e_magic != IMAGE_DOS_SIGNATURE || // "MZ"
|
|
|
967 headers->Signature != IMAGE_NT_SIGNATURE || // "PE\0\0"
|
|
|
968 headers->FileHeader.SizeOfOptionalHeader <
|
|
|
969 sizeof(IMAGE_OPTIONAL_HEADER)) {
|
|
|
970 return false;
|
|
|
971 }
|
|
|
972
|
|
|
973 IMAGE_DATA_DIRECTORY *import_directory =
|
|
|
974 &headers->OptionalHeader.DataDirectory[IMAGE_DIRECTORY_ENTRY_IMPORT];
|
|
|
975
|
|
|
976 // Iterate the list of imported DLLs. FirstThunk will be null for the last
|
|
|
977 // entry.
|
|
|
978 RVAPtr<IMAGE_IMPORT_DESCRIPTOR> imports(module,
|
|
|
979 import_directory->VirtualAddress);
|
|
|
980 for (; imports->FirstThunk != 0; ++imports) {
|
|
|
981 RVAPtr<const char> modname(module, imports->Name);
|
|
|
982 if (_stricmp(&*modname, imported_module) == 0)
|
|
|
983 break;
|
|
|
984 }
|
|
|
985 if (imports->FirstThunk == 0)
|
|
|
986 return false;
|
|
|
987
|
|
|
988 // We have two parallel arrays: the import address table (IAT) and the table
|
|
|
989 // of names. They start out containing the same data, but the loader rewrites
|
|
|
990 // the IAT to hold imported addresses and leaves the name table in
|
|
|
991 // OriginalFirstThunk alone.
|
|
|
992 RVAPtr<IMAGE_THUNK_DATA> name_table(module, imports->OriginalFirstThunk);
|
|
|
993 RVAPtr<IMAGE_THUNK_DATA> iat(module, imports->FirstThunk);
|
|
|
994 for (; name_table->u1.Ordinal != 0; ++name_table, ++iat) {
|
|
|
995 if (!IMAGE_SNAP_BY_ORDINAL(name_table->u1.Ordinal)) {
|
|
|
996 RVAPtr<IMAGE_IMPORT_BY_NAME> import_by_name(
|
|
|
997 module, name_table->u1.ForwarderString);
|
|
|
998 const char *funcname = &import_by_name->Name[0];
|
|
|
999 if (strcmp(funcname, function_name) == 0)
|
|
|
1000 break;
|
|
|
1001 }
|
|
|
1002 }
|
|
|
1003 if (name_table->u1.Ordinal == 0)
|
|
|
1004 return false;
|
|
|
1005
|
|
|
1006 // Now we have the correct IAT entry. Do the swap. We have to make the page
|
|
|
1007 // read/write first.
|
|
|
1008 if (orig_old_func)
|
|
|
1009 *orig_old_func = iat->u1.AddressOfData;
|
|
|
1010 DWORD old_prot, unused_prot;
|
|
|
1011 if (!VirtualProtect(&iat->u1.AddressOfData, 4, PAGE_EXECUTE_READWRITE,
|
|
|
1012 &old_prot))
|
|
|
1013 return false;
|
|
|
1014 iat->u1.AddressOfData = new_function;
|
|
|
1015 if (!VirtualProtect(&iat->u1.AddressOfData, 4, old_prot, &unused_prot))
|
|
|
1016 return false; // Not clear if this failure bothers us.
|
|
|
1017 return true;
|
|
|
1018 }
|
|
|
1019
|
|
|
1020 } // namespace __interception
|
|
|
1021
|
|
|
1022 #endif // SANITIZER_MAC
|
