[BitcodeReader] Diagnose type mismatches with aliases

Bug found with AFL fuzz.

llvm-svn: 238895

1 files changed, 6 insertions, 3 deletions

diff --git a/llvm/lib/Bitcode/Reader/BitcodeReader.cpp b/llvm/lib/Bitcode/Reader/BitcodeReader.cpp
index 9e5e46aae0b..75b3b9fd73c 100644
--- a/llvm/lib/Bitcode/Reader/BitcodeReader.cpp
+++ b/llvm/lib/Bitcode/Reader/BitcodeReader.cpp
@@ -2065,9 +2065,12 @@ std::error_code BitcodeReader::ResolveGlobalAndAliasInits() {
     if (ValID >= ValueList.size()) {
       AliasInits.push_back(AliasInitWorklist.back());
     } else {
-      if (Constant *C = dyn_cast_or_null<Constant>(ValueList[ValID]))
-        AliasInitWorklist.back().first->setAliasee(C);
-      else
+      if (Constant *C = dyn_cast_or_null<Constant>(ValueList[ValID])) {
+        GlobalAlias *Alias = AliasInitWorklist.back().first;
+        if (C->getType() != Alias->getType())
+          return Error("Alias and aliasee types don't match");
+        Alias->setAliasee(C);
+      } else
         return Error("Expected a constant");
     }
     AliasInitWorklist.pop_back();