1 files changed, 74 insertions, 0 deletions
diff --git a/contrib/llvm-project/clang/lib/StaticAnalyzer/Checkers/PutenvStackArrayChecker.cpp b/contrib/llvm-project/clang/lib/StaticAnalyzer/Checkers/PutenvStackArrayChecker.cpp
new file mode 100644
index 000000000000..bf81d57bf82f
--- /dev/null
+++ b/contrib/llvm-project/clang/lib/StaticAnalyzer/Checkers/PutenvStackArrayChecker.cpp
@@ -0,0 +1,74 @@
+//== PutenvStackArrayChecker.cpp ------------------------------- -*- C++ -*--=//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+//
+// This file defines PutenvStackArrayChecker which finds calls of ``putenv``
+// function with automatic array variable as the argument.
+// https://wiki.sei.cmu.edu/confluence/x/6NYxBQ
+//
+//===----------------------------------------------------------------------===//
+
+#include "AllocationState.h"
+#include "clang/StaticAnalyzer/Checkers/BuiltinCheckerRegistration.h"
+#include "clang/StaticAnalyzer/Core/BugReporter/BugType.h"
+#include "clang/StaticAnalyzer/Core/Checker.h"
+#include "clang/StaticAnalyzer/Core/CheckerManager.h"
+#include "clang/StaticAnalyzer/Core/PathSensitive/CallDescription.h"
+#include "clang/StaticAnalyzer/Core/PathSensitive/CallEvent.h"
+#include "clang/StaticAnalyzer/Core/PathSensitive/CheckerContext.h"
+#include "clang/StaticAnalyzer/Core/PathSensitive/MemRegion.h"
+
+using namespace clang;
+using namespace ento;
+
+namespace {
+class PutenvStackArrayChecker : public Checker<check::PostCall> {
+private:
+  BugType BT{this, "'putenv' called with stack-allocated string",
+             categories::SecurityError};
+  const CallDescription Putenv{CDM::CLibrary, {"putenv"}, 1};
+
+public:
+  void checkPostCall(const CallEvent &Call, CheckerContext &C) const;
+};
+} // namespace
+
+void PutenvStackArrayChecker::checkPostCall(const CallEvent &Call,
+                                            CheckerContext &C) const {
+  if (!Putenv.matches(Call))
+    return;
+
+  SVal ArgV = Call.getArgSVal(0);
+  const Expr *ArgExpr = Call.getArgExpr(0);
+
+  const auto *SSR =
+      dyn_cast<StackSpaceRegion>(ArgV.getAsRegion()->getMemorySpace());
+  if (!SSR)
+    return;
+  const auto *StackFrameFuncD =
+      dyn_cast_or_null<FunctionDecl>(SSR->getStackFrame()->getDecl());
+  if (StackFrameFuncD && StackFrameFuncD->isMain())
+    return;
+
+  StringRef ErrorMsg = "The 'putenv' function should not be called with "
+                       "arrays that have automatic storage";
+  ExplodedNode *N = C.generateErrorNode();
+  auto Report = std::make_unique<PathSensitiveBugReport>(BT, ErrorMsg, N);
+
+  // Track the argument.
+  bugreporter::trackExpressionValue(Report->getErrorNode(), ArgExpr, *Report);
+
+  C.emitReport(std::move(Report));
+}
+
+void ento::registerPutenvStackArray(CheckerManager &Mgr) {
+  Mgr.registerChecker<PutenvStackArrayChecker>();
+}
+
+bool ento::shouldRegisterPutenvStackArray(const CheckerManager &) {
+  return true;
+}