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76 lines
2.6 KiB
76 lines
2.6 KiB
//=== CastToStructChecker.cpp - Fixed address usage checker ----*- C++ -*--===//
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//
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// The LLVM Compiler Infrastructure
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//
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// This file is distributed under the University of Illinois Open Source
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// License. See LICENSE.TXT for details.
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//
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//===----------------------------------------------------------------------===//
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//
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// This files defines CastToStructChecker, a builtin checker that checks for
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// cast from non-struct pointer to struct pointer.
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// This check corresponds to CWE-588.
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//
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//===----------------------------------------------------------------------===//
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#include "ClangSACheckers.h"
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#include "clang/StaticAnalyzer/Core/BugReporter/BugType.h"
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#include "clang/StaticAnalyzer/Core/Checker.h"
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#include "clang/StaticAnalyzer/Core/CheckerManager.h"
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#include "clang/StaticAnalyzer/Core/PathSensitive/CheckerContext.h"
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using namespace clang;
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using namespace ento;
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namespace {
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class CastToStructChecker : public Checker< check::PreStmt<CastExpr> > {
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mutable std::unique_ptr<BuiltinBug> BT;
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public:
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void checkPreStmt(const CastExpr *CE, CheckerContext &C) const;
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};
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}
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void CastToStructChecker::checkPreStmt(const CastExpr *CE,
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CheckerContext &C) const {
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const Expr *E = CE->getSubExpr();
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ASTContext &Ctx = C.getASTContext();
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QualType OrigTy = Ctx.getCanonicalType(E->getType());
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QualType ToTy = Ctx.getCanonicalType(CE->getType());
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const PointerType *OrigPTy = dyn_cast<PointerType>(OrigTy.getTypePtr());
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const PointerType *ToPTy = dyn_cast<PointerType>(ToTy.getTypePtr());
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if (!ToPTy || !OrigPTy)
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return;
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QualType OrigPointeeTy = OrigPTy->getPointeeType();
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QualType ToPointeeTy = ToPTy->getPointeeType();
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if (!ToPointeeTy->isStructureOrClassType())
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return;
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// We allow cast from void*.
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if (OrigPointeeTy->isVoidType())
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return;
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// Now the cast-to-type is struct pointer, the original type is not void*.
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if (!OrigPointeeTy->isRecordType()) {
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if (ExplodedNode *N = C.generateNonFatalErrorNode()) {
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if (!BT)
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BT.reset(
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new BuiltinBug(this, "Cast from non-struct type to struct type",
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"Casting a non-structure type to a structure type "
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"and accessing a field can lead to memory access "
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"errors or data corruption."));
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auto R = llvm::make_unique<BugReport>(*BT, BT->getDescription(), N);
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R->addRange(CE->getSourceRange());
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C.emitReport(std::move(R));
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}
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}
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}
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void ento::registerCastToStructChecker(CheckerManager &mgr) {
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mgr.registerChecker<CastToStructChecker>();
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}
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