diff --git a/mlir/lib/Dialect/SparseTensor/Transforms/SparseBufferRewriting.cpp b/mlir/lib/Dialect/SparseTensor/Transforms/SparseBufferRewriting.cpp
--- a/mlir/lib/Dialect/SparseTensor/Transforms/SparseBufferRewriting.cpp
+++ b/mlir/lib/Dialect/SparseTensor/Transforms/SparseBufferRewriting.cpp
@@ -1160,6 +1160,9 @@
   }
 
   auto insertPoint = op->template getParentOfType<func::FuncOp>();
+  if (!insertPoint)
+    return failure();
+
   SmallString<32> funcName;
   FuncGeneratorType funcGenerator;
   uint32_t nTrailingP = 0;