[llvm] r283196 - [Object/ELF] - Avoid possible crash in getExtendedSymbolTableIndex().

[George Rimar via llvm-commits]

Author: grimar
Date: Tue Oct  4 03:44:03 2016
New Revision: 283196

URL: http://llvm.org/viewvc/llvm-project?rev=283196&view=rev
Log:
[Object/ELF] - Avoid possible crash in getExtendedSymbolTableIndex().

When using broken input object found using AFL,
getExtendedSymbolTableIndex() crashed because ShndxTable
was empty as object does not contain SHT_SYMTAB_SHNDX section.

Differential revision: https://reviews.llvm.org/D25189

Added:
    llvm/trunk/test/Object/Inputs/invalid-ext-symtab-index.elf-x86-64   (with props)
Modified:
    llvm/trunk/include/llvm/Object/ELF.h
    llvm/trunk/test/Object/invalid.test

Modified: llvm/trunk/include/llvm/Object/ELF.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/include/llvm/Object/ELF.h?rev=283196&r1=283195&r2=283196&view=diff
==============================================================================
--- llvm/trunk/include/llvm/Object/ELF.h (original)
+++ llvm/trunk/include/llvm/Object/ELF.h Tue Oct  4 03:44:03 2016
@@ -225,7 +225,8 @@ uint32_t ELFFile<ELFT>::getExtendedSymbo
     ArrayRef<Elf_Word> ShndxTable) const {
   assert(Sym->st_shndx == ELF::SHN_XINDEX);
   unsigned Index = Sym - FirstSym;
-
+  if (Index >= ShndxTable.size())
+    report_fatal_error("Invalid symbol table index");
   // The size of the table was checked in getSHNDXTable.
   return ShndxTable[Index];
 }

Added: llvm/trunk/test/Object/Inputs/invalid-ext-symtab-index.elf-x86-64
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Object/Inputs/invalid-ext-symtab-index.elf-x86-64?rev=283196&view=auto
==============================================================================
Binary file - no diff available.

Propchange: llvm/trunk/test/Object/Inputs/invalid-ext-symtab-index.elf-x86-64
------------------------------------------------------------------------------
    svn:mime-type = application/octet-stream

Modified: llvm/trunk/test/Object/invalid.test
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Object/invalid.test?rev=283196&r1=283195&r2=283196&view=diff
==============================================================================
--- llvm/trunk/test/Object/invalid.test (original)
+++ llvm/trunk/test/Object/invalid.test Tue Oct  4 03:44:03 2016
@@ -54,3 +54,7 @@ INVALID-SYMTAB-SIZE: Invalid symbol tabl
 
 RUN: not llvm-readobj -t %p/Inputs/invalid-xindex-size.elf 2>&1 | FileCheck --check-prefix=INVALID-XINDEX-SIZE %s
 INVALID-XINDEX-SIZE: Invalid data was encountered while parsing the file.
+
+RUN: not llvm-readobj -t %p/Inputs/invalid-ext-symtab-index.elf-x86-64 2>&1 | \
+RUN:   FileCheck --check-prefix=INVALID-EXT-SYMTAB-INDEX %s
+INVALID-EXT-SYMTAB-INDEX: Invalid symbol table index