diff --git a/mlir/lib/Dialect/Linalg/Transforms/DropUnitDims.cpp b/mlir/lib/Dialect/Linalg/Transforms/DropUnitDims.cpp
index c3dca148b7f94..4bb4ad61cf8da 100644
--- a/mlir/lib/Dialect/Linalg/Transforms/DropUnitDims.cpp
+++ b/mlir/lib/Dialect/Linalg/Transforms/DropUnitDims.cpp
@@ -578,8 +578,10 @@ linalg::dropUnitDims(RewriterBase &rewriter, GenericOp genericOp,
     b.cloneRegionBefore(genericOp.getRegion(), replacementOp.getRegion(),
                         replacementOp.getRegion().begin());
     // 5a. Replace `linalg.index` operations that refer to the dropped unit
-    //     dimensions.
-    IRRewriter rewriter(b);
+    //     dimensions. Use a fresh IRRewriter to avoid inheriting any listener
+    //     from the builder (e.g., WalkPatternRewriter's erasure listener),
+    //     since the ops being erased here are newly cloned, not the matched op.
+    IRRewriter rewriter(b.getContext());
     replaceUnitDimIndexOps(replacementOp, droppedDims, rewriter);
 
     return replacementOp;
diff --git a/mlir/lib/Transforms/Utils/WalkPatternRewriteDriver.cpp b/mlir/lib/Transforms/Utils/WalkPatternRewriteDriver.cpp
index 1382550e0f7e6..40fcb351ee079 100644
--- a/mlir/lib/Transforms/Utils/WalkPatternRewriteDriver.cpp
+++ b/mlir/lib/Transforms/Utils/WalkPatternRewriteDriver.cpp
@@ -19,6 +19,7 @@
 #include "mlir/IR/Verifier.h"
 #include "mlir/IR/Visitors.h"
 #include "mlir/Rewrite/PatternApplicator.h"
+#include "llvm/ADT/DenseSet.h"
 #include "llvm/ADT/STLExtras.h"
 #include "llvm/Support/DebugLog.h"
 #include "llvm/Support/ErrorHandling.h"
@@ -61,16 +62,38 @@ struct WalkAndApplyPatternsAction final
 // ops/blocks. Because we use walk-based pattern application, erasing the
 // op/block from the *next* iteration (e.g., a user of the visited op) is not
 // valid. Note that this is only used with expensive pattern API checks.
+//
+// Ops and blocks that were *created* during the current pattern application are
+// exempt: they were not in the walk schedule before the pattern ran, so erasing
+// them cannot disrupt the walk.
 struct ErasedOpsListener final : RewriterBase::ForwardingListener {
   using RewriterBase::ForwardingListener::ForwardingListener;
 
+  void notifyOperationInserted(Operation *op,
+                               OpBuilder::InsertPoint previous) override {
+    if (visitedOp)
+      newlyCreatedOps.insert(op);
+    ForwardingListener::notifyOperationInserted(op, previous);
+  }
+
+  void notifyBlockInserted(Block *block, Region *previous,
+                           Region::iterator previousIt) override {
+    if (visitedOp)
+      newlyCreatedBlocks.insert(block);
+    ForwardingListener::notifyBlockInserted(block, previous, previousIt);
+  }
+
   void notifyOperationErased(Operation *op) override {
-    checkErasure(op);
+    if (!newlyCreatedOps.contains(op))
+      checkErasure(op);
+    newlyCreatedOps.erase(op);
     ForwardingListener::notifyOperationErased(op);
   }
 
   void notifyBlockErased(Block *block) override {
-    checkErasure(block->getParentOp());
+    if (!newlyCreatedBlocks.contains(block))
+      checkErasure(block->getParentOp());
+    newlyCreatedBlocks.erase(block);
     ForwardingListener::notifyBlockErased(block);
   }
 
@@ -86,6 +109,9 @@ struct ErasedOpsListener final : RewriterBase::ForwardingListener {
   }
 
   Operation *visitedOp = nullptr;
+  // Ops and blocks inserted since visitedOp was last set; may be freely erased.
+  DenseSet<Operation *> newlyCreatedOps;
+  DenseSet<Block *> newlyCreatedBlocks;
 };
 #endif // MLIR_ENABLE_EXPENSIVE_PATTERN_API_CHECKS
 } // namespace
@@ -204,6 +230,8 @@ void walkAndApplyPatterns(Operation *op,
                    << OpWithFlags(op, OpPrintingFlags().skipRegions());
 #if MLIR_ENABLE_EXPENSIVE_PATTERN_API_CHECKS
             erasedListener.visitedOp = op;
+            erasedListener.newlyCreatedOps.clear();
+            erasedListener.newlyCreatedBlocks.clear();
 #endif // MLIR_ENABLE_EXPENSIVE_PATTERN_API_CHECKS
             if (succeeded(applicator.matchAndRewrite(op, rewriter)))
               LDBG() << "\tOp matched and rewritten";
diff --git a/mlir/test/lib/Dialect/Test/TestPatterns.cpp b/mlir/test/lib/Dialect/Test/TestPatterns.cpp
index 6c44ace831e96..7e8ed94630b61 100644
--- a/mlir/test/lib/Dialect/Test/TestPatterns.cpp
+++ b/mlir/test/lib/Dialect/Test/TestPatterns.cpp
@@ -383,7 +383,8 @@ struct CloneRegionBeforeOp : public RewritePattern {
       return failure();
     for (Region &r : op->getRegions())
       rewriter.cloneRegionBefore(r, op->getBlock());
-    op->setAttr("was_cloned", rewriter.getUnitAttr());
+    rewriter.modifyOpInPlace(
+        op, [&]() { op->setAttr("was_cloned", rewriter.getUnitAttr()); });
     return success();
   }
 };