FixedAddressChecker.cpp revision 360784 
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
21using namespace clang;
22using namespace ento;
23
24namespace {
25class FixedAddressChecker
26  : public Checker< check::PreStmt<BinaryOperator> > {
27  mutable std::unique_ptr<BuiltinBug> BT;
28
29public:
30  void checkPreStmt(const BinaryOperator *B, CheckerContext &C) const;
31};
32}
33
34void 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
65void ento::registerFixedAddressChecker(CheckerManager &mgr) {
66  mgr.registerChecker<FixedAddressChecker>();
67}
68
69bool ento::shouldRegisterFixedAddressChecker(const LangOptions &LO) {
70  return true;
71}
72