Fix a nullptr dereferencing in a FuncBufferizableOpInterfaceImpl.cpp::getCalledFunction

[paul0403]

There is a potential nullptr dereferencing in the helper function getCalledFunction when bufferizing call ops.
The solution is making the nullptr check explicit before dereferencing it.

Fixes #150441.

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[llvmbot]

@llvm/pr-subscribers-mlir-bufferization

Author: Paul (paul0403)

Changes

There is a potential nullptr dereferencing in the helper function getCalledFunction when bufferizing call ops.
The solution is making the nullptr check explicit before dereferencing it.

Fixes issue #150441

---

Full diff: https://github.com/llvm/llvm-project/pull/150518.diff

1 Files Affected:

• (modified) mlir/lib/Dialect/Bufferization/Transforms/FuncBufferizableOpInterfaceImpl.cpp (+3-2)

diff --git a/mlir/lib/Dialect/Bufferization/Transforms/FuncBufferizableOpInterfaceImpl.cpp b/mlir/lib/Dialect/Bufferization/Transforms/FuncBufferizableOpInterfaceImpl.cpp
index 2a98203da9d7d..ac0ef0edb0438 100644
--- a/mlir/lib/Dialect/Bufferization/Transforms/FuncBufferizableOpInterfaceImpl.cpp
+++ b/mlir/lib/Dialect/Bufferization/Transforms/FuncBufferizableOpInterfaceImpl.cpp
@@ -90,8 +90,9 @@ static FuncOp getCalledFunction(CallOpInterface callOp,
                                 const AnalysisState &state) {
   auto &oneShotAnalysisState = static_cast<const OneShotAnalysisState &>(state);
 
-  if (auto *funcAnalysisState =
-          oneShotAnalysisState.getExtension<FuncAnalysisState>()) {
+  auto *funcAnalysisState =
+      oneShotAnalysisState.getExtension<FuncAnalysisState>();
+  if (funcAnalysisState != nullptr) {
     // Use the cached symbol tables.
     return getCalledFunction(callOp, funcAnalysisState->symbolTables);
   }

[llvmbot]

@llvm/pr-subscribers-mlir

Author: Paul (paul0403)

Changes

There is a potential nullptr dereferencing in the helper function getCalledFunction when bufferizing call ops.
The solution is making the nullptr check explicit before dereferencing it.

Fixes issue #150441

---

Full diff: https://github.com/llvm/llvm-project/pull/150518.diff

1 Files Affected:

• (modified) mlir/lib/Dialect/Bufferization/Transforms/FuncBufferizableOpInterfaceImpl.cpp (+3-2)

diff --git a/mlir/lib/Dialect/Bufferization/Transforms/FuncBufferizableOpInterfaceImpl.cpp b/mlir/lib/Dialect/Bufferization/Transforms/FuncBufferizableOpInterfaceImpl.cpp
index 2a98203da9d7d..ac0ef0edb0438 100644
--- a/mlir/lib/Dialect/Bufferization/Transforms/FuncBufferizableOpInterfaceImpl.cpp
+++ b/mlir/lib/Dialect/Bufferization/Transforms/FuncBufferizableOpInterfaceImpl.cpp
@@ -90,8 +90,9 @@ static FuncOp getCalledFunction(CallOpInterface callOp,
                                 const AnalysisState &state) {
   auto &oneShotAnalysisState = static_cast<const OneShotAnalysisState &>(state);
 
-  if (auto *funcAnalysisState =
-          oneShotAnalysisState.getExtension<FuncAnalysisState>()) {
+  auto *funcAnalysisState =
+      oneShotAnalysisState.getExtension<FuncAnalysisState>();
+  if (funcAnalysisState != nullptr) {
     // Use the cached symbol tables.
     return getCalledFunction(callOp, funcAnalysisState->symbolTables);
   }

[CoTinker]

Maybe change to:

if (!funcAnalysisState)

And please add a test.

[matthias-springer]

Does this really fix the issue?

auto *x = abc();
if (x != nullptr) foo();

is identical to

if (auto *x = abc()) foo();

[paul0403]

I think you are right, I need to investigate the segfault more. Maybe this is not where the root cause is...