1//== PutenvWithAutoChecker.cpp --------------------------------- -*- C++ -*--=// 2// 3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. 4// See https://llvm.org/LICENSE.txt for license information. 5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception 6// 7//===----------------------------------------------------------------------===// 8// 9// This file defines PutenvWithAutoChecker which finds calls of ``putenv`` 10// function with automatic variable as the argument. 11// https://wiki.sei.cmu.edu/confluence/x/6NYxBQ 12// 13//===----------------------------------------------------------------------===// 14 15#include "../AllocationState.h" 16#include "clang/StaticAnalyzer/Checkers/BuiltinCheckerRegistration.h" 17#include "clang/StaticAnalyzer/Core/BugReporter/BugType.h" 18#include "clang/StaticAnalyzer/Core/Checker.h" 19#include "clang/StaticAnalyzer/Core/CheckerManager.h" 20#include "clang/StaticAnalyzer/Core/PathSensitive/CallEvent.h" 21#include "clang/StaticAnalyzer/Core/PathSensitive/CheckerContext.h" 22#include "clang/StaticAnalyzer/Core/PathSensitive/MemRegion.h" 23 24using namespace clang; 25using namespace ento; 26 27namespace { 28class PutenvWithAutoChecker : public Checker<check::PostCall> { 29private: 30 BugType BT{this, "'putenv' function should not be called with auto variables", 31 categories::SecurityError}; 32 const CallDescription Putenv{"putenv", 1}; 33 34public: 35 void checkPostCall(const CallEvent &Call, CheckerContext &C) const; 36}; 37} // namespace 38 39void PutenvWithAutoChecker::checkPostCall(const CallEvent &Call, 40 CheckerContext &C) const { 41 if (!Call.isCalled(Putenv)) 42 return; 43 44 SVal ArgV = Call.getArgSVal(0); 45 const Expr *ArgExpr = Call.getArgExpr(0); 46 const MemSpaceRegion *MSR = ArgV.getAsRegion()->getMemorySpace(); 47 48 if (!isa<StackSpaceRegion>(MSR)) 49 return; 50 51 StringRef ErrorMsg = "The 'putenv' function should not be called with " 52 "arguments that have automatic storage"; 53 ExplodedNode *N = C.generateErrorNode(); 54 auto Report = std::make_unique<PathSensitiveBugReport>(BT, ErrorMsg, N); 55 56 // Track the argument. 57 bugreporter::trackExpressionValue(Report->getErrorNode(), ArgExpr, *Report); 58 59 C.emitReport(std::move(Report)); 60} 61 62void ento::registerPutenvWithAuto(CheckerManager &Mgr) { 63 Mgr.registerChecker<PutenvWithAutoChecker>(); 64} 65 66bool ento::shouldRegisterPutenvWithAuto(const CheckerManager &) { return true; } 67