Index: lib/DebugInfo/DWARF/DWARFDebugLine.cpp
===================================================================
--- lib/DebugInfo/DWARF/DWARFDebugLine.cpp
+++ lib/DebugInfo/DWARF/DWARFDebugLine.cpp
@@ -449,6 +449,9 @@
 DWARFDebugLine::getOrParseLineTable(DWARFDataExtractor &DebugLineData,
                                     uint32_t Offset, const DWARFContext &Ctx,
                                     const DWARFUnit *U) {
+  if (!DebugLineData.isValidOffset(Offset))
+    return nullptr;
+
   std::pair<LineTableIter, bool> Pos =
       LineTableMap.insert(LineTableMapTy::value_type(Offset, LineTable()));
   LineTable *LT = &Pos.first->second;
Index: unittests/DebugInfo/DWARF/CMakeLists.txt
===================================================================
--- unittests/DebugInfo/DWARF/CMakeLists.txt
+++ unittests/DebugInfo/DWARF/CMakeLists.txt
@@ -10,7 +10,9 @@
 
 set(DebugInfoSources
   DwarfGenerator.cpp
+  DwarfUtils.cpp
   DWARFDebugInfoTest.cpp
+  DWARFDebugLineTest.cpp
   DWARFFormValueTest.cpp
   )
 
Index: unittests/DebugInfo/DWARF/DWARFDebugInfoTest.cpp
===================================================================
--- unittests/DebugInfo/DWARF/DWARFDebugInfoTest.cpp
+++ unittests/DebugInfo/DWARF/DWARFDebugInfoTest.cpp
@@ -1,4 +1,4 @@
-//===- llvm/unittest/DebugInfo/DWARFFormValueTest.cpp ---------------------===//
+//===- llvm/unittest/DebugInfo/DWARFDebugInfoTest.cpp ---------------------===//
 //
 //                     The LLVM Compiler Infrastructure
 //
@@ -8,6 +8,7 @@
 //===----------------------------------------------------------------------===//
 
 #include "DwarfGenerator.h"
+#include "DwarfUtils.h"
 #include "llvm/ADT/ArrayRef.h"
 #include "llvm/ADT/Optional.h"
 #include "llvm/ADT/SmallString.h"
@@ -36,36 +37,10 @@
 
 using namespace llvm;
 using namespace dwarf;
+using namespace utils;
 
 namespace {
 
-void initLLVMIfNeeded() {
-  static bool gInitialized = false;
-  if (!gInitialized) {
-    gInitialized = true;
-    InitializeAllTargets();
-    InitializeAllTargetMCs();
-    InitializeAllAsmPrinters();
-    InitializeAllAsmParsers();
-  }
-}
-
-Triple getHostTripleForAddrSize(uint8_t AddrSize) {
-  Triple PT(Triple::normalize(LLVM_HOST_TRIPLE));
-
-  if (AddrSize == 8 && PT.isArch32Bit())
-    return PT.get64BitArchVariant();
-  if (AddrSize == 4 && PT.isArch64Bit())
-    return PT.get32BitArchVariant();
-  return PT;
-}
-
-static bool isConfigurationSupported(Triple &T) {
-  initLLVMIfNeeded();
-  std::string Err;
-  return TargetRegistry::lookupTarget(T.getTriple(), Err);
-}
-
 template <uint16_t Version, class AddrType, class RefAddrType>
 void TestAllForms() {
   Triple Triple = getHostTripleForAddrSize(sizeof(AddrType));
Index: unittests/DebugInfo/DWARF/DWARFDebugLineTest.cpp
===================================================================
--- unittests/DebugInfo/DWARF/DWARFDebugLineTest.cpp
+++ unittests/DebugInfo/DWARF/DWARFDebugLineTest.cpp
@@ -0,0 +1,64 @@
+//===- DWARFDebugLineTest.cpp ---------------------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#include "DwarfGenerator.h"
+#include "DwarfUtils.h"
+#include "llvm/DebugInfo/DWARF/DWARFContext.h"
+#include "llvm/DebugInfo/DWARF/DWARFDebugLine.h"
+#include "llvm/Object/ObjectFile.h"
+#include "llvm/Testing/Support/Error.h"
+#include "gtest/gtest.h"
+
+using namespace llvm;
+using namespace dwarf;
+using namespace object;
+using namespace utils;
+
+namespace {
+
+struct DebugLineGenerator {
+  bool init() {
+    Triple T = getHostTripleForAddrSize(8);
+    if (!isConfigurationSupported(T))
+      return false;
+    auto ExpectedGenerator = dwarfgen::Generator::create(T, 4);
+    if (ExpectedGenerator)
+      Generator.reset(ExpectedGenerator->release());
+    return true;
+  }
+
+  std::unique_ptr<DWARFContext> createContext() {
+    if (!Generator)
+      return nullptr;
+    StringRef FileBytes = Generator->generate();
+    MemoryBufferRef FileBuffer(FileBytes, "dwarf");
+    auto Obj = object::ObjectFile::createObjectFile(FileBuffer);
+    if (Obj)
+      return DWARFContext::create(**Obj);
+    return nullptr;
+  }
+
+  std::unique_ptr<dwarfgen::Generator> Generator;
+};
+
+TEST(DWARFDebugLine, GetLineTableAtInvalidOffset) {
+  DebugLineGenerator LineGen;
+  if (!LineGen.init())
+    return;
+
+  DWARFDebugLine Line;
+  std::unique_ptr<DWARFContext> Context = LineGen.createContext();
+  ASSERT_TRUE(Context != nullptr);
+  const DWARFObject &Obj = Context->getDWARFObj();
+  DWARFDataExtractor LineData(Obj, Obj.getLineSection(), true, 8);
+
+  EXPECT_EQ(Line.getOrParseLineTable(LineData, 0, *Context, nullptr), nullptr);
+}
+
+} // end anonymous namespace
Index: unittests/DebugInfo/DWARF/DwarfUtils.h
===================================================================
--- unittests/DebugInfo/DWARF/DwarfUtils.h
+++ unittests/DebugInfo/DWARF/DwarfUtils.h
@@ -0,0 +1,29 @@
+//===--- unittests/DebugInfo/DWARF/DwarfUtils.h -----------------*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_UNITTESTS_DEBUG_INFO_DWARF_DWARFUTILS_H
+#define LLVM_UNITTESTS_DEBUG_INFO_DWARF_DWARFUTILS_H
+
+#include <cstdint>
+
+namespace llvm {
+
+class Triple;
+
+namespace dwarf {
+namespace utils {
+
+Triple getHostTripleForAddrSize(uint8_t AddrSize);
+bool isConfigurationSupported(Triple &T);
+
+} // end namespace utils
+} // end namespace dwarf
+} // end namespace llvm
+
+#endif // LLVM_UNITTESTS_DEBUG_INFO_DWARF_DWARFUTILS_H
Index: unittests/DebugInfo/DWARF/DwarfUtils.cpp
===================================================================
--- unittests/DebugInfo/DWARF/DwarfUtils.cpp
+++ unittests/DebugInfo/DWARF/DwarfUtils.cpp
@@ -0,0 +1,42 @@
+//===--- unittests/DebugInfo/DWARF/DwarfUtils.cpp ---------------*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#include "DwarfUtils.h"
+#include "llvm/ADT/Triple.h"
+#include "llvm/Support/TargetRegistry.h"
+#include "llvm/Support/TargetSelect.h"
+
+using namespace llvm;
+
+static void initLLVMIfNeeded() {
+  static bool gInitialized = false;
+  if (!gInitialized) {
+    gInitialized = true;
+    InitializeAllTargets();
+    InitializeAllTargetMCs();
+    InitializeAllAsmPrinters();
+    InitializeAllAsmParsers();
+  }
+}
+
+Triple llvm::dwarf::utils::getHostTripleForAddrSize(uint8_t AddrSize) {
+  Triple T(Triple::normalize(LLVM_HOST_TRIPLE));
+
+  if (AddrSize == 8 && T.isArch32Bit())
+    return T.get64BitArchVariant();
+  if (AddrSize == 4 && T.isArch64Bit())
+    return T.get32BitArchVariant();
+  return T;
+}
+
+bool llvm::dwarf::utils::isConfigurationSupported(Triple &T) {
+  initLLVMIfNeeded();
+  std::string Err;
+  return TargetRegistry::lookupTarget(T.getTriple(), Err);
+}