Fix several issues found by fuzzing (#1931)

Fixes #1922, fixes #1924, fixes #1929

Co-authored-by: Keith Winstein <keithw@cs.stanford.edu>

3 files changed, 15 insertions, 0 deletions

diff --git a/src/decompiler-ast.h b/src/decompiler-ast.h
index 584a8373..e5dd358e 100644
--- a/src/decompiler-ast.h
+++ b/src/decompiler-ast.h
@@ -226,6 +226,11 @@ struct AST {
             mc.GetLabel(cast<BrIfExpr>(&e)->var)->label_type;
         return;
       }
+      case ExprType::BrTable: {
+        InsertNode(NodeType::Expr, ExprType::BrTable, &e, 1).u.lt =
+            mc.GetLabel(cast<BrTableExpr>(&e)->default_target)->label_type;
+        return;
+      }
       default: {
         InsertNode(NodeType::Expr, e.type(), &e, arity.nargs);
         return;
diff --git a/src/decompiler-naming.h b/src/decompiler-naming.h
index 91f841f8..bb7a0819 100644
--- a/src/decompiler-naming.h
+++ b/src/decompiler-naming.h
@@ -85,6 +85,9 @@ inline void RenameToIdentifier(std::string& name,
   if (s.size() > max_identifier_length) {
     s.resize(max_identifier_length);
   }
+  if (s.empty()) {
+    s = "__empty";
+  }
   // Remove original binding first, such that it doesn't match with our
   // new name.
   bh.erase(name);
diff --git a/src/interp/binary-reader-interp.cc b/src/interp/binary-reader-interp.cc
index e1696ce2..05296220 100644
--- a/src/interp/binary-reader-interp.cc
+++ b/src/interp/binary-reader-interp.cc
@@ -1139,6 +1139,9 @@ Result BinaryReaderInterp::OnCallIndirectExpr(Index sig_index,
 }
 
 Result BinaryReaderInterp::OnReturnCallExpr(Index func_index) {
+  CHECK_RESULT(
+      validator_.OnReturnCall(GetLocation(), Var(func_index, GetLocation())));
+
   FuncType& func_type = func_types_[func_index];
 
   Index drop_count, keep_count, catch_drop_count;
@@ -1169,6 +1172,10 @@ Result BinaryReaderInterp::OnReturnCallExpr(Index func_index) {
 
 Result BinaryReaderInterp::OnReturnCallIndirectExpr(Index sig_index,
                                                     Index table_index) {
+  CHECK_RESULT(validator_.OnReturnCallIndirect(
+      GetLocation(), Var(sig_index, GetLocation()),
+      Var(table_index, GetLocation())));
+
   FuncType& func_type = module_.func_types[sig_index];
 
   Index drop_count, keep_count, catch_drop_count;