[llvm] r321863 - [DebugInfo] Don't crash when given invalid DWARFv5 line table prologue.

[Jonas Devlieghere via llvm-commits]

Author: jdevlieghere
Date: Fri Jan  5 02:03:02 2018
New Revision: 321863

URL: http://llvm.org/viewvc/llvm-project?rev=321863&view=rev
Log:
[DebugInfo] Don't crash when given invalid DWARFv5 line table prologue.

This patch replaces an assertion with an explicit check for the validity
of the FORM parameters. The assertion was triggered when the DWARFv5
line table contained a zero address size.

This fixes OSS-Fuzz Issue 4644
https://bugs.chromium.org/p/oss-fuzz/issues/detail?id=4644

Differential revision: https://reviews.llvm.org/D41615

Added:
    llvm/trunk/test/DebugInfo/Inputs/invalid.linetable
    llvm/trunk/test/DebugInfo/dwarfdump-invalid-line-table.test
Modified:
    llvm/trunk/include/llvm/DebugInfo/DWARF/DWARFFormValue.h
    llvm/trunk/lib/DebugInfo/DWARF/DWARFDebugLine.cpp
    llvm/trunk/lib/DebugInfo/DWARF/DWARFFormValue.cpp

Modified: llvm/trunk/include/llvm/DebugInfo/DWARF/DWARFFormValue.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/include/llvm/DebugInfo/DWARF/DWARFFormValue.h?rev=321863&r1=321862&r2=321863&view=diff
==============================================================================
--- llvm/trunk/include/llvm/DebugInfo/DWARF/DWARFFormValue.h (original)
+++ llvm/trunk/include/llvm/DebugInfo/DWARF/DWARFFormValue.h Fri Jan  5 02:03:02 2018
@@ -50,6 +50,8 @@ struct DWARFFormParams {
     }
     llvm_unreachable("Invalid Format value");
   }
+
+  explicit operator bool() const { return Version && AddrSize; }
 };
 
 class DWARFFormValue {

Modified: llvm/trunk/lib/DebugInfo/DWARF/DWARFDebugLine.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/DebugInfo/DWARF/DWARFDebugLine.cpp?rev=321863&r1=321862&r2=321863&view=diff
==============================================================================
--- llvm/trunk/lib/DebugInfo/DWARF/DWARFDebugLine.cpp (original)
+++ llvm/trunk/lib/DebugInfo/DWARF/DWARFDebugLine.cpp Fri Jan  5 02:03:02 2018
@@ -268,7 +268,7 @@ bool DWARFDebugLine::Prologue::parse(con
 
   if (getVersion() >= 5) {
     if (!parseV5DirFileTables(DebugLineData, OffsetPtr, EndPrologueOffset,
-                              getFormParams(), U, HasMD5, IncludeDirectories,
+                              FormParams, U, HasMD5, IncludeDirectories,
                               FileNames)) {
       fprintf(stderr,
               "warning: parsing line table prologue at 0x%8.8" PRIx64

Modified: llvm/trunk/lib/DebugInfo/DWARF/DWARFFormValue.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/DebugInfo/DWARF/DWARFFormValue.cpp?rev=321863&r1=321862&r2=321863&view=diff
==============================================================================
--- llvm/trunk/lib/DebugInfo/DWARF/DWARFFormValue.cpp (original)
+++ llvm/trunk/lib/DebugInfo/DWARF/DWARFFormValue.cpp Fri Jan  5 02:03:02 2018
@@ -64,8 +64,9 @@ DWARFFormValue::getFixedByteSize(dwarf::
                                  const DWARFFormParams Params) {
   switch (Form) {
   case DW_FORM_addr:
-    assert(Params.Version && Params.AddrSize && "Invalid Params for form");
-    return Params.AddrSize;
+    if (Params)
+      return Params.AddrSize;
+    return None;
 
   case DW_FORM_block:          // ULEB128 length L followed by L bytes.
   case DW_FORM_block1:         // 1 byte length L followed by L bytes.
@@ -86,8 +87,9 @@ DWARFFormValue::getFixedByteSize(dwarf::
     return None;
 
   case DW_FORM_ref_addr:
-    assert(Params.Version && Params.AddrSize && "Invalid Params for form");
-    return Params.getRefAddrByteSize();
+    if (Params)
+      return Params.getRefAddrByteSize();
+    return None;
 
   case DW_FORM_flag:
   case DW_FORM_data1:
@@ -118,8 +120,9 @@ DWARFFormValue::getFixedByteSize(dwarf::
   case DW_FORM_line_strp:
   case DW_FORM_sec_offset:
   case DW_FORM_strp_sup:
-    assert(Params.Version && Params.AddrSize && "Invalid Params for form");
-    return Params.getDwarfOffsetByteSize();
+    if (Params)
+      return Params.getDwarfOffsetByteSize();
+    return None;
 
   case DW_FORM_data8:
   case DW_FORM_ref8:

Added: llvm/trunk/test/DebugInfo/Inputs/invalid.linetable
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/DebugInfo/Inputs/invalid.linetable?rev=321863&view=auto
==============================================================================
Binary files llvm/trunk/test/DebugInfo/Inputs/invalid.linetable (added) and llvm/trunk/test/DebugInfo/Inputs/invalid.linetable Fri Jan  5 02:03:02 2018 differ

Added: llvm/trunk/test/DebugInfo/dwarfdump-invalid-line-table.test
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/DebugInfo/dwarfdump-invalid-line-table.test?rev=321863&view=auto
==============================================================================
--- llvm/trunk/test/DebugInfo/dwarfdump-invalid-line-table.test (added)
+++ llvm/trunk/test/DebugInfo/dwarfdump-invalid-line-table.test Fri Jan  5 02:03:02 2018
@@ -0,0 +1,5 @@
+Verify that dwarfdump doesn't crash on invalid line table prologue.
+OSS-Fuzz Issue 4644 (https://bugs.chromium.org/p/oss-fuzz/issues/detail?id=4644)
+
+RUN: llvm-dwarfdump --verbose %p/Inputs/invalid.linetable 2>&1 | FileCheck %s --check-prefix=INVALID-LINE-TABLE
+INVALID-LINE-TABLE: invalid directory or file table description