| 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 | const BugType BT{this, "Use fixed address"}; |
| 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 | // FIXME: improve grammar in the following strings: |
| 53 | constexpr llvm::StringLiteral Msg = |
| 54 | "Using a fixed address is not portable because that address will " |
| 55 | "probably not be valid in all environments or platforms."; |
| 56 | auto R = std::make_unique<PathSensitiveBugReport>(args: BT, args: Msg, args&: N); |
| 57 | R->addRange(R: B->getRHS()->getSourceRange()); |
| 58 | C.emitReport(R: std::move(R)); |
| 59 | } |
| 60 | } |
| 61 | |
| 62 | void ento::registerFixedAddressChecker(CheckerManager &mgr) { |
| 63 | mgr.registerChecker<FixedAddressChecker>(); |
| 64 | } |
| 65 | |
| 66 | bool ento::shouldRegisterFixedAddressChecker(const CheckerManager &mgr) { |
| 67 | return true; |
| 68 | } |
| 69 |