[lld] r290238 - [ELF] - Fix use of freed memory.

[George Rimar via llvm-commits]

Author: grimar
Date: Wed Dec 21 02:11:49 2016
New Revision: 290238

URL: http://llvm.org/viewvc/llvm-project?rev=290238&view=rev
Log:
[ELF] - Fix use of freed memory.

It was revealed by D27831.

If we have linkerscript that includes another one that sets OUTPUT for example:

RUN: echo "INCLUDE \"foo.script\"" > %t.script
RUN: echo "OUTPUT(\"%t.out\")" > %T/foo.script
then we do:

void ScriptParser::readInclude() {
...
  std::unique_ptr<MemoryBuffer> &MB = *MBOrErr;
  tokenize(MB->getMemBufferRef());
  OwningMBs.push_back(std::move(MB));
}

void ScriptParser::readOutput() {
...
    Config->OutputFile = unquote(Tok);
...
}
Problem is that OwningMBs are destroyed after script parser do its job.
So all Toks are dead and Config->OutputFile points to destroyed data.

Patch suggests to save all included scripts into using string Saver.

Differential revision: https://reviews.llvm.org/D27987

Modified:
    lld/trunk/ELF/LinkerScript.cpp

Modified: lld/trunk/ELF/LinkerScript.cpp
URL: http://llvm.org/viewvc/llvm-project/lld/trunk/ELF/LinkerScript.cpp?rev=290238&r1=290237&r2=290238&view=diff
==============================================================================
--- lld/trunk/ELF/LinkerScript.cpp (original)
+++ lld/trunk/ELF/LinkerScript.cpp Wed Dec 21 02:11:49 2016
@@ -1030,7 +1030,6 @@ private:
 
   ScriptConfiguration &Opt = *ScriptConfig;
   bool IsUnderSysroot;
-  std::vector<std::unique_ptr<MemoryBuffer>> OwningMBs;
 };
 
 void ScriptParser::readDynamicList() {
@@ -1180,8 +1179,7 @@ void ScriptParser::readInclude() {
     return;
   }
   std::unique_ptr<MemoryBuffer> &MB = *MBOrErr;
-  tokenize(MB->getMemBufferRef());
-  OwningMBs.push_back(std::move(MB));
+  tokenize({Saver.save(MB->getBuffer()), unquote(Tok)});
 }
 
 void ScriptParser::readOutput() {