[llvm] r236027 - Relax an assert when there's a type mismatch in forward references

[Filipe Cabecinhas]

Author: filcab
Date: Tue Apr 28 15:18:47 2015
New Revision: 236027

URL: http://llvm.org/viewvc/llvm-project?rev=236027&view=rev
Log:
Relax an assert when there's a type mismatch in forward references

Summary:
We don't seem to need to assert here, since this function's callers expect
to get a nullptr on error. This way we don't assert on user input.

Bug found with AFL fuzz.

Reviewers: rafael

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D9308

Added:
    llvm/trunk/test/Bitcode/Inputs/invalid-fwdref-type-mismatch.bc
Modified:
    llvm/trunk/lib/Bitcode/Reader/BitcodeReader.cpp
    llvm/trunk/test/Bitcode/invalid.test

Modified: llvm/trunk/lib/Bitcode/Reader/BitcodeReader.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Bitcode/Reader/BitcodeReader.cpp?rev=236027&r1=236026&r2=236027&view=diff
==============================================================================
--- llvm/trunk/lib/Bitcode/Reader/BitcodeReader.cpp (original)
+++ llvm/trunk/lib/Bitcode/Reader/BitcodeReader.cpp Tue Apr 28 15:18:47 2015
@@ -794,7 +794,9 @@ Value *BitcodeReaderValueList::getValueF
     resize(Idx + 1);
 
   if (Value *V = ValuePtrs[Idx]) {
-    assert((!Ty || Ty == V->getType()) && "Type mismatch in value table!");
+    // If the types don't match, it's invalid.
+    if (Ty && Ty != V->getType())
+      return nullptr;
     return V;
   }
 

Added: llvm/trunk/test/Bitcode/Inputs/invalid-fwdref-type-mismatch.bc
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Bitcode/Inputs/invalid-fwdref-type-mismatch.bc?rev=236027&view=auto
==============================================================================
Binary files llvm/trunk/test/Bitcode/Inputs/invalid-fwdref-type-mismatch.bc (added) and llvm/trunk/test/Bitcode/Inputs/invalid-fwdref-type-mismatch.bc Tue Apr 28 15:18:47 2015 differ

Modified: llvm/trunk/test/Bitcode/invalid.test
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Bitcode/invalid.test?rev=236027&r1=236026&r2=236027&view=diff
==============================================================================
--- llvm/trunk/test/Bitcode/invalid.test (original)
+++ llvm/trunk/test/Bitcode/invalid.test Tue Apr 28 15:18:47 2015
@@ -93,3 +93,8 @@ RUN: not llvm-dis -disable-output %p/Inp
 RUN:   FileCheck --check-prefix=INVALID-TYPE %s
 
 INVALID-TYPE: Invalid type for value
+
+RUN: not llvm-dis -disable-output %p/Inputs/invalid-fwdref-type-mismatch.bc 2>&1 | \
+RUN:   FileCheck --check-prefix=FWDREF-TYPE %s
+
+FWDREF-TYPE: Invalid record