[llvm] r358491 - llvm-undname: Fix nullptr deref on invalid structor names in template args

[Nico Weber via llvm-commits]

Author: nico
Date: Tue Apr 16 07:10:34 2019
New Revision: 358491

URL: http://llvm.org/viewvc/llvm-project?rev=358491&view=rev
Log:
llvm-undname: Fix nullptr deref on invalid structor names in template args

Similar to r358421: A StructorIndentifierNode has a Class field which
is read when printing it, but if the StructorIndentifierNode appears in
a template argument then demangleFullyQualifiedSymbolName() which sets
Class isn't called. Since StructorIndentifierNodes are always leaf
names, we can just reject them as well.

Found by oss-fuzz.

Modified:
    llvm/trunk/lib/Demangle/MicrosoftDemangle.cpp
    llvm/trunk/test/Demangle/invalid-manglings.test

Modified: llvm/trunk/lib/Demangle/MicrosoftDemangle.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Demangle/MicrosoftDemangle.cpp?rev=358491&r1=358490&r2=358491&view=diff
==============================================================================
--- llvm/trunk/lib/Demangle/MicrosoftDemangle.cpp (original)
+++ llvm/trunk/lib/Demangle/MicrosoftDemangle.cpp Tue Apr 16 07:10:34 2019
@@ -949,9 +949,10 @@ Demangler::demangleTemplateInstantiation
 
   if (NBB & NBB_Template) {
     // NBB_Template is only set for types and non-leaf names ("a::" in "a::b").
-    // A conversion operator only makes sense in a leaf name , so reject it in
-    // NBB_Template contexts.
-    if (Identifier->kind() == NodeKind::ConversionOperatorIdentifier) {
+    // Structors and conversion operators only makes sense in a leaf name, so
+    // reject them in NBB_Template contexts.
+    if (Identifier->kind() == NodeKind::ConversionOperatorIdentifier ||
+        Identifier->kind() == NodeKind::StructorIdentifier) {
       Error = true;
       return nullptr;
     }

Modified: llvm/trunk/test/Demangle/invalid-manglings.test
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Demangle/invalid-manglings.test?rev=358491&r1=358490&r2=358491&view=diff
==============================================================================
--- llvm/trunk/test/Demangle/invalid-manglings.test (original)
+++ llvm/trunk/test/Demangle/invalid-manglings.test Tue Apr 16 07:10:34 2019
@@ -134,3 +134,8 @@
 ; CHECK-EMPTY:
 ; CHECK-NEXT: ?foo@?$?BH@@QAEHXZ
 ; CHECK-NEXT: error: Invalid mangled name
+
+?foo@?$?0H@
+; CHECK-EMPTY:
+; CHECK-NEXT: ?foo@?$?0H@
+; CHECK-NEXT: error: Invalid mangled name