[regexp] Adhere to the stack limit in the interpreter

This introduces a limit for the interpreter's BacktrackStack to match
the limit used by generated code (RegExpStack::kMaximumStackSize).

Bug: chromium:1006670
Change-Id: I0b7613698e61257aecca89535ad9109c7e454692
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1821458
Commit-Queue: Jakob Gruber <jgruber@chromium.org>
Commit-Queue: Peter Marshall <petermarshall@chromium.org>
Auto-Submit: Jakob Gruber <jgruber@chromium.org>
Reviewed-by: Peter Marshall <petermarshall@chromium.org>
Cr-Commit-Position: refs/heads/master@{#63945}

src/regexp/regexp-interpreter.cc

@@ -12,6 +12,7 @@
 #include "src/objects/objects-inl.h"
 #include "src/regexp/regexp-bytecodes.h"
 #include "src/regexp/regexp-macro-assembler.h"
+#include "src/regexp/regexp-stack.h"  // For kMaximumStackSize.
 #include "src/regexp/regexp.h"
 #include "src/strings/unicode.h"
 #include "src/utils/utils.h"
@@ -118,7 +119,10 @@ class BacktrackStack {
  public:
   BacktrackStack() = default;
 
-  void push(int v) { data_.emplace_back(v); }
+  V8_WARN_UNUSED_RESULT bool push(int v) {
+    data_.emplace_back(v);
+    return (static_cast<int>(data_.size()) <= kMaxSize);
+  }
   int peek() const {
     DCHECK(!data_.empty());
     return data_.back();
@@ -141,13 +145,17 @@ class BacktrackStack {
   // static stack-allocated backing store, but small enough not to waste space.
   static constexpr int kStaticCapacity = 64;
 
-  base::SmallVector<int, kStaticCapacity> data_;
+  using ValueT = int;
+  base::SmallVector<ValueT, kStaticCapacity> data_;
+
+  static constexpr int kMaxSize =
+      RegExpStack::kMaximumStackSize / sizeof(ValueT);
 
   DISALLOW_COPY_AND_ASSIGN(BacktrackStack);
 };
 
-IrregexpInterpreter::Result StackOverflow(Isolate* isolate,
-                                          RegExp::CallOrigin call_origin) {
+IrregexpInterpreter::Result ThrowStackOverflow(Isolate* isolate,
+                                               RegExp::CallOrigin call_origin) {
   CHECK(call_origin == RegExp::CallOrigin::kFromRuntime);
   // We abort interpreter execution after the stack overflow is thrown, and thus
   // allow allocation here despite the outer DisallowHeapAllocationScope.
@@ -156,6 +164,17 @@ IrregexpInterpreter::Result StackOverflow(Isolate* isolate,
   return IrregexpInterpreter::EXCEPTION;
 }
 
+// Only throws if called from the runtime, otherwise just returns the EXCEPTION
+// status code.
+IrregexpInterpreter::Result MaybeThrowStackOverflow(
+    Isolate* isolate, RegExp::CallOrigin call_origin) {
+  if (call_origin == RegExp::CallOrigin::kFromRuntime) {
+    return ThrowStackOverflow(isolate, call_origin);
+  } else {
+    return IrregexpInterpreter::EXCEPTION;
+  }
+}
+
 template <typename Char>
 void UpdateCodeAndSubjectReferences(
     Isolate* isolate, Handle<ByteArray> code_array,
@@ -208,7 +227,7 @@ IrregexpInterpreter::Result HandleInterrupts(
     Handle<String> subject_handle(*subject_string_out, isolate);
 
     if (js_has_overflowed) {
-      return StackOverflow(isolate, call_origin);
+      return ThrowStackOverflow(isolate, call_origin);
     } else if (check.InterruptRequested()) {
       const bool was_one_byte =
           String::IsOneByteRepresentationUnderneath(*subject_string_out);
@@ -376,17 +395,23 @@ IrregexpInterpreter::Result RawMatch(Isolate* isolate, ByteArray code_array,
     BYTECODE(BREAK) { UNREACHABLE(); }
     BYTECODE(PUSH_CP) {
       ADVANCE(PUSH_CP);
-      backtrack_stack.push(current);
+      if (!backtrack_stack.push(current)) {
+        return MaybeThrowStackOverflow(isolate, call_origin);
+      }
       DISPATCH();
     }
     BYTECODE(PUSH_BT) {
       ADVANCE(PUSH_BT);
-      backtrack_stack.push(Load32Aligned(pc + 4));
+      if (!backtrack_stack.push(Load32Aligned(pc + 4))) {
+        return MaybeThrowStackOverflow(isolate, call_origin);
+      }
       DISPATCH();
     }
     BYTECODE(PUSH_REGISTER) {
       ADVANCE(PUSH_REGISTER);
-      backtrack_stack.push(registers[insn >> BYTECODE_SHIFT]);
+      if (!backtrack_stack.push(registers[insn >> BYTECODE_SHIFT])) {
+        return MaybeThrowStackOverflow(isolate, call_origin);
+      }
       DISPATCH();
     }
     BYTECODE(SET_REGISTER) {

src/regexp/regexp-stack.h

@@ -73,6 +73,9 @@ class RegExpStack {
   char* RestoreStack(char* from);
   void FreeThreadResources() { thread_local_.Free(); }
 
+  // Maximal size of allocated stack area.
+  static constexpr size_t kMaximumStackSize = 64 * MB;
+
  private:
   RegExpStack();
   ~RegExpStack();
@@ -84,9 +87,6 @@ class RegExpStack {
   // Minimal size of allocated stack area.
   static const size_t kMinimumStackSize = 1 * KB;
 
-  // Maximal size of allocated stack area.
-  static const size_t kMaximumStackSize = 64 * MB;
-
   // Structure holding the allocated memory, size and limit.
   struct ThreadLocal {
     ThreadLocal() { Clear(); }

test/mjsunit/regress/regress-1006670.js

@@ -0,0 +1,5 @@
+// Copyright 2019 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+assertThrows(() => /(a?;?){4000000}/.exec("a"), RangeError);