From 24adce95b27e97b972fddcbcd93cf90421f8689d Mon Sep 17 00:00:00 2001
From: George Rimar <grimar@accesssoftek.com>
Date: Thu, 6 Oct 2016 09:17:55 +0000
Subject: [PATCH] [ELF] - Make checks in ObjectFile<ELFT>::getSection()
 stricter.

This patch makes the check for null section stricter,
so it is only allowed for STT_SECTION symbols now.

Differential revision: https://reviews.llvm.org/D25231

llvm-svn: 283426
---
 lld/ELF/InputFiles.cpp                         |  11 ++++++++---
 lld/test/ELF/invalid/Inputs/section-index2.elf | Bin 0 -> 474 bytes
 lld/test/ELF/invalid/invalid-elf.test          |   4 ++++
 3 files changed, 12 insertions(+), 3 deletions(-)
 create mode 100644 lld/test/ELF/invalid/Inputs/section-index2.elf

diff --git a/lld/ELF/InputFiles.cpp b/lld/ELF/InputFiles.cpp
index 3562609..e8f2bee 100644
--- a/lld/ELF/InputFiles.cpp
+++ b/lld/ELF/InputFiles.cpp
@@ -377,17 +377,22 @@ template <class ELFT>
 InputSectionBase<ELFT> *
 elf::ObjectFile<ELFT>::getSection(const Elf_Sym &Sym) const {
   uint32_t Index = this->getSectionIndex(Sym);
-  if (Index == 0)
-    return nullptr;
   if (Index >= Sections.size())
     fatal(getFilename(this) + ": invalid section index: " + Twine(Index));
   InputSectionBase<ELFT> *S = Sections[Index];
+
   // We found that GNU assembler 2.17.50 [FreeBSD] 2007-07-03
   // could generate broken objects. STT_SECTION symbols can be
   // associated with SHT_REL[A]/SHT_SYMTAB/SHT_STRTAB sections.
   // In this case it is fine for section to be null here as we
   // do not allocate sections of these types.
-  if (!S || S == &InputSectionBase<ELFT>::Discarded)
+  if (!S) {
+    if (Index == 0 || Sym.getType() == STT_SECTION)
+      return nullptr;
+    fatal(getFilename(this) + ": invalid section index: " + Twine(Index));
+  }
+
+  if (S == &InputSectionBase<ELFT>::Discarded)
     return S;
   return S->Repl;
 }
diff --git a/lld/test/ELF/invalid/Inputs/section-index2.elf b/lld/test/ELF/invalid/Inputs/section-index2.elf
new file mode 100644
index 0000000000000000000000000000000000000000..5d842880b3755a5fafdaec8e9904d132618f068d
GIT binary patch
literal 474
zcmb<-^>JfjWMqH=Mg}_u1P><4z~F#jLfH-stPCtjqU13_c7ZS(n)U{$BhYO?cbg<o
z9}}8h5Vr%W&;TmO45UHoIG}t9C@l!2L2~F|2UI`0edv64phj%^cS02^q8W^?A59u7
kml5c4HK+_CJoHLZD@qvjiZhB!ib@ibfGikYnG50r0KXLw)c^nh

literal 0
HcmV?d00001

diff --git a/lld/test/ELF/invalid/invalid-elf.test b/lld/test/ELF/invalid/invalid-elf.test
index 350a420..ce459d4 100644
--- a/lld/test/ELF/invalid/invalid-elf.test
+++ b/lld/test/ELF/invalid/invalid-elf.test
@@ -20,6 +20,10 @@
 # RUN:   FileCheck --check-prefix=INVALID-SECTION-INDEX-LLD %s
 # INVALID-SECTION-INDEX-LLD: invalid section index
 
+## section-index2.elf has local symbol with incorrect section index.
+# RUN: not ld.lld %p/Inputs/section-index2.elf -o %t2 2>&1 | \
+# RUN:   FileCheck --check-prefix=INVALID-SECTION-INDEX-LLD %s
+
 # RUN: not ld.lld %p/Inputs/shstrndx.so -o %t2 2>&1 | \
 # RUN:   FileCheck --check-prefix=INVALID-SECTION-INDEX %s
 # INVALID-SECTION-INDEX: Invalid section index
-- 
2.7.4