From fa1a4b2275a4419dd575c229e842d9162ae7cb84 Mon Sep 17 00:00:00 2001
From: Rafael Espindola <rafael.espindola@gmail.com>
Date: Mon, 20 Jul 2015 03:38:17 +0000
Subject: [PATCH] llvm-readobj: Handle invalid references to the string table.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@242658 91177308-0d34-0410-b5e6-96231b3b80d8
---
 .../Inputs/corrupt-invalid-strtab.elf.x86-64    | Bin 0 -> 1712 bytes
 test/Object/corrupt.test                        |   7 +++++++
 tools/llvm-readobj/ELFDumper.cpp                |  16 ++++++++++++----
 tools/llvm-readobj/llvm-readobj.cpp             |   6 +++---
 tools/llvm-readobj/llvm-readobj.h               |   1 +
 5 files changed, 23 insertions(+), 7 deletions(-)
 create mode 100755 test/Object/Inputs/corrupt-invalid-strtab.elf.x86-64

diff --git a/test/Object/Inputs/corrupt-invalid-strtab.elf.x86-64 b/test/Object/Inputs/corrupt-invalid-strtab.elf.x86-64
new file mode 100755
index 0000000000000000000000000000000000000000..bdaa3cf920824ee8f8b2c8f71617a776e3c5250f
GIT binary patch
literal 1712
zcmcIk%}N_l6h8T}^(O@_T`0K7!h%qGA#~GjO4@2gP*=JT3ge_nO`w@TW-Q67K0=pW
z`Uoz3ge-iFzJgDn=bJg-IF1ua13fVFo%@}?d*+_GKezWjmrEs~ROG$fuSA+OWUwi3
zrK*;iEXfn)tNJv}p2t7N6X$J>8gr%>!NfK}l;y+=G-{HctRy_~Dp?AVab=6Uw!GIC
zN4&H+BKK+ZBS4yExw#!Ze`rEn5&vQeFJ7nZN4|JoD-69b@`sU9L7Q1Cs^I&g9(43k
zB={zfy7jk|EM?WuXgN1!(fBn()PP*jF<Jh%H|j0u1Kc?{lGDNWcD>;mjlWb(wpUHh
zpYHKDD$hy&JfEq<znn*XiobZ@#M?SP_^`kGY5JMDs56Sh=~0SnkApB8iVFr&$DIae
z4lTa^(HVxlL6DfoeQ{ks?8Ym<-}@>q>}pWtw^SpJ`|&y+6Sg}uzS2m{2Iq+LLOij|
zu;W|vKj0kIl*`WHxy=ia^JHn_9Mpkt^ud46`WF^Y+<=pc(P@30F9bXu&U<<fFaS;&
zVH~M<svs6UKsYbF7x@2kf9&6`ANis&D8+dG|04z<X-4w(pQ;TxXN|`_f*g5a{q>w7
zU;j|;MO*!C<S&cI{eV5Pf1dxI@#dDorZx03WfCQSEFYC-?^)M<BU@Qg^?dvt*57H@

literal 0
HcmV?d00001

diff --git a/test/Object/corrupt.test b/test/Object/corrupt.test
index 0a655704610..2181c7e8907 100644
--- a/test/Object/corrupt.test
+++ b/test/Object/corrupt.test
@@ -24,3 +24,10 @@ RUN: not llvm-readobj %p/Inputs/corrupt-version.elf-x86_64 -dt \
 RUN:     2>&1 | FileCheck --check-prefix=VER %s
 
 VER: Error reading file: Invalid data was encountered while parsing the file.
+
+
+// The file is missing the dynamic string table but has references to it.
+RUN: not llvm-readobj -dynamic-table %p/Inputs/corrupt-invalid-strtab.elf.x86-64 \
+RUN:     2>&1 | FileCheck --check-prefix=STRTAB %s
+
+STRTAB: Invalid dynamic string table reference
diff --git a/tools/llvm-readobj/ELFDumper.cpp b/tools/llvm-readobj/ELFDumper.cpp
index 3deeb8dfe5b..045f4dfc636 100644
--- a/tools/llvm-readobj/ELFDumper.cpp
+++ b/tools/llvm-readobj/ELFDumper.cpp
@@ -953,6 +953,14 @@ void printFlags(T Value, ArrayRef<EnumEntry<TFlag>> Flags, raw_ostream &OS) {
   }
 }
 
+template <class ELFT>
+static const char *getDynamicString(const ELFFile<ELFT> &O, uint64_t Value) {
+  const char *Ret = O.getDynamicString(Value);
+  if (!Ret)
+    reportError("Invalid dynamic string table reference");
+  return Ret;
+}
+
 template <class ELFT>
 static void printValue(const ELFFile<ELFT> *O, uint64_t Type, uint64_t Value,
                        bool Is64, raw_ostream &OS) {
@@ -1011,14 +1019,14 @@ static void printValue(const ELFFile<ELFT> *O, uint64_t Type, uint64_t Value,
     OS << Value << " (bytes)";
     break;
   case DT_NEEDED:
-    OS << "SharedLibrary (" << O->getDynamicString(Value) << ")";
+    OS << "SharedLibrary (" << getDynamicString(*O, Value) << ")";
     break;
   case DT_SONAME:
-    OS << "LibrarySoname (" << O->getDynamicString(Value) << ")";
+    OS << "LibrarySoname (" << getDynamicString(*O, Value) << ")";
     break;
   case DT_RPATH:
   case DT_RUNPATH:
-    OS << O->getDynamicString(Value);
+    OS << getDynamicString(*O, Value);
     break;
   case DT_MIPS_FLAGS:
     printFlags(Value, makeArrayRef(ElfDynamicDTMipsFlags), OS);
@@ -1088,7 +1096,7 @@ void ELFDumper<ELFT>::printNeededLibraries() {
 
   for (const auto &Entry : Obj->dynamic_table())
     if (Entry.d_tag == ELF::DT_NEEDED)
-      Libs.push_back(Obj->getDynamicString(Entry.d_un.d_val));
+      Libs.push_back(getDynamicString(*Obj, Entry.d_un.d_val));
 
   std::stable_sort(Libs.begin(), Libs.end());
 
diff --git a/tools/llvm-readobj/llvm-readobj.cpp b/tools/llvm-readobj/llvm-readobj.cpp
index b525ce10004..3f03618bb22 100644
--- a/tools/llvm-readobj/llvm-readobj.cpp
+++ b/tools/llvm-readobj/llvm-readobj.cpp
@@ -188,14 +188,14 @@ namespace opts {
 
 } // namespace opts
 
-static void reportError(Twine Msg) {
+namespace llvm {
+
+void reportError(Twine Msg) {
   outs() << Msg << "\n";
   outs().flush();
   exit(1);
 }
 
-namespace llvm {
-
 void error(std::error_code EC) {
   if (!EC)
     return;
diff --git a/tools/llvm-readobj/llvm-readobj.h b/tools/llvm-readobj/llvm-readobj.h
index 8872fc21a39..58c50f58d75 100644
--- a/tools/llvm-readobj/llvm-readobj.h
+++ b/tools/llvm-readobj/llvm-readobj.h
@@ -19,6 +19,7 @@ namespace llvm {
   }
 
   // Various helper functions.
+  void reportError(Twine Msg);
   void error(std::error_code ec);
   bool relocAddressLess(object::RelocationRef A,
                         object::RelocationRef B);
-- 
2.34.1