v8: backport fix for CVE-2013-{6639|6640}

Quoting CVE-2013-6639:

    The DehoistArrayIndex function in hydrogen-dehoist.cc in Google V8
    before 3.22.24.7, as used in Google Chrome before 31.0.1650.63,
    allows remote attackers to cause a denial of service (out-of-bounds
    write) or possibly have unspecified other impact via JavaScript code
    that sets the value of an array element with a crafted index.

Quoting CVE-2013-6640:

    The DehoistArrayIndex function in hydrogen-dehoist.cc in Google V8
    before 3.22.24.7, as used in Google Chrome before 31.0.1650.63,
    allows remote attackers to cause a denial of service (out-of-bounds
    read) via JavaScript code that sets a variable to the value of an
    array element with a crafted index.

Like 6b92a7, this is unlikely to affect node.js because it only runs
local, trusted code.  However, if there exists some module somewhere
that populates an array index with remotely provided data this could
very well be used to crash a remote server running node.  Defense in
depth and all.

This is a backport of upstream commit r17801. Original commit log:

    Limit size of dehoistable array indices

    LOG=Y
    BUG=chromium:319835,chromium:319860
    R=dslomov@chromium.org

    Review URL: https://codereview.chromium.org/74113002

deps/v8/src/elements-kind.cc

@@ -35,6 +35,36 @@ namespace v8 {
 namespace internal {
 
 
+int ElementsKindToShiftSize(ElementsKind elements_kind) {
+  switch (elements_kind) {
+    case EXTERNAL_BYTE_ELEMENTS:
+    case EXTERNAL_PIXEL_ELEMENTS:
+    case EXTERNAL_UNSIGNED_BYTE_ELEMENTS:
+      return 0;
+    case EXTERNAL_SHORT_ELEMENTS:
+    case EXTERNAL_UNSIGNED_SHORT_ELEMENTS:
+      return 1;
+    case EXTERNAL_INT_ELEMENTS:
+    case EXTERNAL_UNSIGNED_INT_ELEMENTS:
+    case EXTERNAL_FLOAT_ELEMENTS:
+      return 2;
+    case EXTERNAL_DOUBLE_ELEMENTS:
+    case FAST_DOUBLE_ELEMENTS:
+    case FAST_HOLEY_DOUBLE_ELEMENTS:
+      return 3;
+    case FAST_SMI_ELEMENTS:
+    case FAST_ELEMENTS:
+    case FAST_HOLEY_SMI_ELEMENTS:
+    case FAST_HOLEY_ELEMENTS:
+    case DICTIONARY_ELEMENTS:
+    case NON_STRICT_ARGUMENTS_ELEMENTS:
+      return kPointerSizeLog2;
+  }
+  UNREACHABLE();
+  return 0;
+}
+
+
 void PrintElementsKind(FILE* out, ElementsKind kind) {
   ElementsAccessor* accessor = ElementsAccessor::ForKind(kind);
   PrintF(out, "%s", accessor->name());

deps/v8/src/elements-kind.h

@@ -77,6 +77,8 @@ const int kElementsKindCount = LAST_ELEMENTS_KIND - FIRST_ELEMENTS_KIND + 1;
 const int kFastElementsKindCount = LAST_FAST_ELEMENTS_KIND -
     FIRST_FAST_ELEMENTS_KIND + 1;
 
+int ElementsKindToShiftSize(ElementsKind elements_kind);
+
 void PrintElementsKind(FILE* out, ElementsKind kind);
 
 ElementsKind GetInitialFastElementsKind();

deps/v8/src/hydrogen-instructions.h

@@ -4240,6 +4240,7 @@ class ArrayInstructionInterface {
   virtual HValue* GetKey() = 0;
   virtual void SetKey(HValue* key) = 0;
   virtual void SetIndexOffset(uint32_t index_offset) = 0;
+  virtual int MaxIndexOffsetBits() = 0;
   virtual bool IsDehoisted() = 0;
   virtual void SetDehoisted(bool is_dehoisted) = 0;
   virtual ~ArrayInstructionInterface() { };
@@ -4274,6 +4275,7 @@ class HLoadKeyedFastElement
   void SetIndexOffset(uint32_t index_offset) {
     bit_field_ = IndexOffsetField::update(bit_field_, index_offset);
   }
+  int MaxIndexOffsetBits() { return 25; }
   HValue* GetKey() { return key(); }
   void SetKey(HValue* key) { SetOperandAt(1, key); }
   bool IsDehoisted() { return IsDehoistedField::decode(bit_field_); }
@@ -4343,6 +4345,7 @@ class HLoadKeyedFastDoubleElement
   HValue* dependency() { return OperandAt(2); }
   uint32_t index_offset() { return index_offset_; }
   void SetIndexOffset(uint32_t index_offset) { index_offset_ = index_offset; }
+  int MaxIndexOffsetBits() { return 25; }
   HValue* GetKey() { return key(); }
   void SetKey(HValue* key) { SetOperandAt(1, key); }
   bool IsDehoisted() { return is_dehoisted_; }
@@ -4420,6 +4423,7 @@ class HLoadKeyedSpecializedArrayElement
   ElementsKind elements_kind() const { return elements_kind_; }
   uint32_t index_offset() { return index_offset_; }
   void SetIndexOffset(uint32_t index_offset) { index_offset_ = index_offset; }
+  int MaxIndexOffsetBits() { return 25; }
   HValue* GetKey() { return key(); }
   void SetKey(HValue* key) { SetOperandAt(1, key); }
   bool IsDehoisted() { return is_dehoisted_; }
@@ -4595,6 +4599,7 @@ class HStoreKeyedFastElement
   }
   uint32_t index_offset() { return index_offset_; }
   void SetIndexOffset(uint32_t index_offset) { index_offset_ = index_offset; }
+  int MaxIndexOffsetBits() { return 25; }
   HValue* GetKey() { return key(); }
   void SetKey(HValue* key) { SetOperandAt(1, key); }
   bool IsDehoisted() { return is_dehoisted_; }
@@ -4648,6 +4653,7 @@ class HStoreKeyedFastDoubleElement
   HValue* value() { return OperandAt(2); }
   uint32_t index_offset() { return index_offset_; }
   void SetIndexOffset(uint32_t index_offset) { index_offset_ = index_offset; }
+  int MaxIndexOffsetBits() { return 25; }
   HValue* GetKey() { return key(); }
   void SetKey(HValue* key) { SetOperandAt(1, key); }
   bool IsDehoisted() { return is_dehoisted_; }
@@ -4706,6 +4712,9 @@ class HStoreKeyedSpecializedArrayElement
   ElementsKind elements_kind() const { return elements_kind_; }
   uint32_t index_offset() { return index_offset_; }
   void SetIndexOffset(uint32_t index_offset) { index_offset_ = index_offset; }
+  int MaxIndexOffsetBits() {
+    return 31 - ElementsKindToShiftSize(elements_kind_);
+  }
   HValue* GetKey() { return key(); }
   void SetKey(HValue* key) { SetOperandAt(1, key); }
   bool IsDehoisted() { return is_dehoisted_; }

deps/v8/src/hydrogen.cc

@@ -3737,7 +3737,7 @@ static void DehoistArrayIndex(ArrayInstructionInterface* array_operation) {
   int32_t value = constant->Integer32Value() * sign;
   // We limit offset values to 30 bits because we want to avoid the risk of
   // overflows when the offset is added to the object header size.
-  if (value >= 1 << 30 || value < 0) return;
+  if (value >= 1 << array_operation->MaxIndexOffsetBits() || value < 0) return;
   array_operation->SetKey(subexpression);
   if (index->HasNoUses()) {
     index->DeleteAndReplaceWith(NULL);

deps/v8/src/lithium.cc

@@ -227,36 +227,6 @@ void LPointerMap::PrintTo(StringStream* stream) {
 }
 
 
-int ElementsKindToShiftSize(ElementsKind elements_kind) {
-  switch (elements_kind) {
-    case EXTERNAL_BYTE_ELEMENTS:
-    case EXTERNAL_PIXEL_ELEMENTS:
-    case EXTERNAL_UNSIGNED_BYTE_ELEMENTS:
-      return 0;
-    case EXTERNAL_SHORT_ELEMENTS:
-    case EXTERNAL_UNSIGNED_SHORT_ELEMENTS:
-      return 1;
-    case EXTERNAL_INT_ELEMENTS:
-    case EXTERNAL_UNSIGNED_INT_ELEMENTS:
-    case EXTERNAL_FLOAT_ELEMENTS:
-      return 2;
-    case EXTERNAL_DOUBLE_ELEMENTS:
-    case FAST_DOUBLE_ELEMENTS:
-    case FAST_HOLEY_DOUBLE_ELEMENTS:
-      return 3;
-    case FAST_SMI_ELEMENTS:
-    case FAST_ELEMENTS:
-    case FAST_HOLEY_SMI_ELEMENTS:
-    case FAST_HOLEY_ELEMENTS:
-    case DICTIONARY_ELEMENTS:
-    case NON_STRICT_ARGUMENTS_ELEMENTS:
-      return kPointerSizeLog2;
-  }
-  UNREACHABLE();
-  return 0;
-}
-
-
 LLabel* LChunk::GetLabel(int block_id) const {
   HBasicBlock* block = graph_->blocks()->at(block_id);
   int first_instruction = block->first_instruction_index();

deps/v8/src/lithium.h

@@ -704,9 +704,6 @@ class LChunk: public ZoneObject {
 };
 
 
-int ElementsKindToShiftSize(ElementsKind elements_kind);
-
-
 } }  // namespace v8::internal
 
 #endif  // V8_LITHIUM_H_

deps/v8/test/mjsunit/regress/regress-crbug-319835.js

@@ -0,0 +1,51 @@
+// Copyright 2013 the V8 project authors. All rights reserved.
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+//       notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+//       copyright notice, this list of conditions and the following
+//       disclaimer in the documentation and/or other materials provided
+//       with the distribution.
+//     * Neither the name of Google Inc. nor the names of its
+//       contributors may be used to endorse or promote products derived
+//       from this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+// Flags: --allow-natives-syntax
+
+try {} catch(e) {}  // No need to optimize the top level.
+
+var size = 0x20000;
+var a = new Float64Array(size);
+var training = new Float64Array(10);
+function store(a, index) {
+  var offset = 0x20000000;
+  for (var i = 0; i < 1; i++) {
+    a[index + offset] = 0xcc;
+  }
+}
+
+store(training, -0x20000000);
+store(training, -0x20000000 + 1);
+store(training, -0x20000000);
+store(training, -0x20000000 + 1);
+%OptimizeFunctionOnNextCall(store);
+
+// Segfault maybe?
+for (var i = -0x20000000; i < -0x20000000 + size; i++) {
+  store(a, i);
+}

deps/v8/test/mjsunit/regress/regress-crbug-319860.js

@@ -0,0 +1,47 @@
+// Copyright 2013 the V8 project authors. All rights reserved.
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+//       notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+//       copyright notice, this list of conditions and the following
+//       disclaimer in the documentation and/or other materials provided
+//       with the distribution.
+//     * Neither the name of Google Inc. nor the names of its
+//       contributors may be used to endorse or promote products derived
+//       from this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+// Flags: --allow-natives-syntax
+
+function read(a, index) {
+  var offset = 0x2000000;
+  var result;
+  for (var i = 0; i < 1; i++) {
+    result = a[index + offset];
+  }
+  return result;
+}
+
+var a = new Int8Array(0x2000001);
+read(a, 0);
+read(a, 0);
+%OptimizeFunctionOnNextCall(read);
+
+// Segfault maybe?
+for (var i = 0; i > -1000000; --i) {
+  read(a, i);
+}