1 //=== FixedAddressChecker.cpp - Fixed address usage checker ----*- 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 files defines FixedAddressChecker, a builtin checker that checks for 10 // assignment of a fixed address to a pointer. 11 // This check corresponds to CWE-587. 12 // 13 //===----------------------------------------------------------------------===// 14 15 #include "clang/StaticAnalyzer/Checkers/BuiltinCheckerRegistration.h" 16 #include "clang/StaticAnalyzer/Core/BugReporter/BugType.h" 17 #include "clang/StaticAnalyzer/Core/Checker.h" 18 #include "clang/StaticAnalyzer/Core/CheckerManager.h" 19 #include "clang/StaticAnalyzer/Core/PathSensitive/CheckerContext.h" 20 21 using namespace clang; 22 using namespace ento; 23 24 namespace { 25 class FixedAddressChecker 26 : public Checker< check::PreStmt<BinaryOperator> > { 27 mutable std::unique_ptr<BuiltinBug> BT; 28 29 public: 30 void checkPreStmt(const BinaryOperator *B, CheckerContext &C) const; 31 }; 32 } 33 34 void FixedAddressChecker::checkPreStmt(const BinaryOperator *B, 35 CheckerContext &C) const { 36 // Using a fixed address is not portable because that address will probably 37 // not be valid in all environments or platforms. 38 39 if (B->getOpcode() != BO_Assign) 40 return; 41 42 QualType T = B->getType(); 43 if (!T->isPointerType()) 44 return; 45 46 SVal RV = C.getSVal(B->getRHS()); 47 48 if (!RV.isConstant() || RV.isZeroConstant()) 49 return; 50 51 if (ExplodedNode *N = C.generateNonFatalErrorNode()) { 52 if (!BT) 53 BT.reset( 54 new BuiltinBug(this, "Use fixed address", 55 "Using a fixed address is not portable because that " 56 "address will probably not be valid in all " 57 "environments or platforms.")); 58 auto R = 59 std::make_unique<PathSensitiveBugReport>(*BT, BT->getDescription(), N); 60 R->addRange(B->getRHS()->getSourceRange()); 61 C.emitReport(std::move(R)); 62 } 63 } 64 65 void ento::registerFixedAddressChecker(CheckerManager &mgr) { 66 mgr.registerChecker<FixedAddressChecker>(); 67 } 68 69 bool ento::shouldRegisterFixedAddressChecker(const CheckerManager &mgr) { 70 return true; 71 } 72