diff options
Diffstat (limited to 'clang/lib/StaticAnalyzer/Checkers')
6 files changed, 89 insertions, 42 deletions
diff --git a/clang/lib/StaticAnalyzer/Checkers/CStringChecker.cpp b/clang/lib/StaticAnalyzer/Checkers/CStringChecker.cpp index 0ae784c..1444114 100644 --- a/clang/lib/StaticAnalyzer/Checkers/CStringChecker.cpp +++ b/clang/lib/StaticAnalyzer/Checkers/CStringChecker.cpp @@ -251,6 +251,8 @@ public: const Expr *Ex, const MemRegion *MR, bool hypothetical); + static const StringLiteral *getStringLiteralFromRegion(const MemRegion *MR); + SVal getCStringLength(CheckerContext &C, ProgramStateRef &state, const Expr *Ex, @@ -983,6 +985,21 @@ SVal CStringChecker::getCStringLengthForRegion(CheckerContext &C, return strLength; } +const StringLiteral * +CStringChecker::getStringLiteralFromRegion(const MemRegion *MR) { + switch (MR->getKind()) { + case MemRegion::StringRegionKind: + return cast<StringRegion>(MR)->getStringLiteral(); + case MemRegion::NonParamVarRegionKind: + if (const VarDecl *Decl = cast<NonParamVarRegion>(MR)->getDecl(); + Decl->getType().isConstQualified() && Decl->hasGlobalStorage()) + return dyn_cast_or_null<StringLiteral>(Decl->getInit()); + return nullptr; + default: + return nullptr; + } +} + SVal CStringChecker::getCStringLength(CheckerContext &C, ProgramStateRef &state, const Expr *Ex, SVal Buf, bool hypothetical) const { @@ -1013,30 +1030,19 @@ SVal CStringChecker::getCStringLength(CheckerContext &C, ProgramStateRef &state, // its length. For anything we can't figure out, just return UnknownVal. MR = MR->StripCasts(); - switch (MR->getKind()) { - case MemRegion::StringRegionKind: { - // Modifying the contents of string regions is undefined [C99 6.4.5p6], - // so we can assume that the byte length is the correct C string length. - SValBuilder &svalBuilder = C.getSValBuilder(); - QualType sizeTy = svalBuilder.getContext().getSizeType(); - const StringLiteral *strLit = cast<StringRegion>(MR)->getStringLiteral(); - return svalBuilder.makeIntVal(strLit->getLength(), sizeTy); - } - case MemRegion::NonParamVarRegionKind: { + if (const StringLiteral *StrLit = getStringLiteralFromRegion(MR)) { // If we have a global constant with a string literal initializer, // compute the initializer's length. - const VarDecl *Decl = cast<NonParamVarRegion>(MR)->getDecl(); - if (Decl->getType().isConstQualified() && Decl->hasGlobalStorage()) { - if (const Expr *Init = Decl->getInit()) { - if (auto *StrLit = dyn_cast<StringLiteral>(Init)) { - SValBuilder &SvalBuilder = C.getSValBuilder(); - QualType SizeTy = SvalBuilder.getContext().getSizeType(); - return SvalBuilder.makeIntVal(StrLit->getLength(), SizeTy); - } - } - } - [[fallthrough]]; + // Modifying the contents of string regions is undefined [C99 6.4.5p6], + // so we can assume that the byte length is the correct C string length. + // FIXME: Embedded null characters are not handled. + SValBuilder &SVB = C.getSValBuilder(); + return SVB.makeIntVal(StrLit->getLength(), SVB.getContext().getSizeType()); } + + switch (MR->getKind()) { + case MemRegion::StringRegionKind: + case MemRegion::NonParamVarRegionKind: case MemRegion::SymbolicRegionKind: case MemRegion::AllocaRegionKind: case MemRegion::ParamVarRegionKind: @@ -1046,10 +1052,28 @@ SVal CStringChecker::getCStringLength(CheckerContext &C, ProgramStateRef &state, case MemRegion::CompoundLiteralRegionKind: // FIXME: Can we track this? Is it necessary? return UnknownVal(); - case MemRegion::ElementRegionKind: - // FIXME: How can we handle this? It's not good enough to subtract the - // offset from the base string length; consider "123\x00567" and &a[5]. + case MemRegion::ElementRegionKind: { + // If an offset into the string literal is used, use the original length + // minus the offset. + // FIXME: Embedded null characters are not handled. + const ElementRegion *ER = cast<ElementRegion>(MR); + const SubRegion *SuperReg = + cast<SubRegion>(ER->getSuperRegion()->StripCasts()); + const StringLiteral *StrLit = getStringLiteralFromRegion(SuperReg); + if (!StrLit) + return UnknownVal(); + SValBuilder &SVB = C.getSValBuilder(); + NonLoc Idx = ER->getIndex(); + QualType SizeTy = SVB.getContext().getSizeType(); + NonLoc LengthVal = + SVB.makeIntVal(StrLit->getLength(), SizeTy).castAs<NonLoc>(); + if (state->assume(SVB.evalBinOpNN(state, BO_LE, Idx, LengthVal, + SVB.getConditionType()) + .castAs<DefinedOrUnknownSVal>(), + true)) + return SVB.evalBinOp(state, BO_Sub, LengthVal, Idx, SizeTy); return UnknownVal(); + } default: // Other regions (mostly non-data) can't have a reliable C string length. // In this case, an error is emitted and UndefinedVal is returned. @@ -1074,6 +1098,7 @@ SVal CStringChecker::getCStringLength(CheckerContext &C, ProgramStateRef &state, const StringLiteral *CStringChecker::getCStringLiteral(CheckerContext &C, ProgramStateRef &state, const Expr *expr, SVal val) const { + // FIXME: use getStringLiteralFromRegion (and remove unused parameters)? // Get the memory region pointed to by the val. const MemRegion *bufRegion = val.getAsRegion(); diff --git a/clang/lib/StaticAnalyzer/Checkers/CheckSecuritySyntaxOnly.cpp b/clang/lib/StaticAnalyzer/Checkers/CheckSecuritySyntaxOnly.cpp index 17af1ae..5e75c1c 100644 --- a/clang/lib/StaticAnalyzer/Checkers/CheckSecuritySyntaxOnly.cpp +++ b/clang/lib/StaticAnalyzer/Checkers/CheckSecuritySyntaxOnly.cpp @@ -154,15 +154,15 @@ void WalkAST::VisitCallExpr(CallExpr *CE) { .Case("mkstemp", &WalkAST::checkCall_mkstemp) .Case("mkdtemp", &WalkAST::checkCall_mkstemp) .Case("mkstemps", &WalkAST::checkCall_mkstemp) - .Cases("strcpy", "__strcpy_chk", &WalkAST::checkCall_strcpy) - .Cases("strcat", "__strcat_chk", &WalkAST::checkCall_strcat) - .Cases("sprintf", "vsprintf", "scanf", "wscanf", "fscanf", "fwscanf", - "vscanf", "vwscanf", "vfscanf", "vfwscanf", + .Cases({"strcpy", "__strcpy_chk"}, &WalkAST::checkCall_strcpy) + .Cases({"strcat", "__strcat_chk"}, &WalkAST::checkCall_strcat) + .Cases({"sprintf", "vsprintf", "scanf", "wscanf", "fscanf", "fwscanf", + "vscanf", "vwscanf", "vfscanf", "vfwscanf"}, &WalkAST::checkDeprecatedOrUnsafeBufferHandling) - .Cases("sscanf", "swscanf", "vsscanf", "vswscanf", "swprintf", - "snprintf", "vswprintf", "vsnprintf", "memcpy", "memmove", + .Cases({"sscanf", "swscanf", "vsscanf", "vswscanf", "swprintf", + "snprintf", "vswprintf", "vsnprintf", "memcpy", "memmove"}, &WalkAST::checkDeprecatedOrUnsafeBufferHandling) - .Cases("strncpy", "strncat", "memset", "fprintf", + .Cases({"strncpy", "strncat", "memset", "fprintf"}, &WalkAST::checkDeprecatedOrUnsafeBufferHandling) .Case("drand48", &WalkAST::checkCall_rand) .Case("erand48", &WalkAST::checkCall_rand) @@ -766,12 +766,14 @@ void WalkAST::checkDeprecatedOrUnsafeBufferHandling(const CallExpr *CE, int ArgIndex = llvm::StringSwitch<int>(Name) - .Cases("scanf", "wscanf", "vscanf", "vwscanf", 0) - .Cases("fscanf", "fwscanf", "vfscanf", "vfwscanf", "sscanf", - "swscanf", "vsscanf", "vswscanf", 1) - .Cases("sprintf", "vsprintf", "fprintf", 1) - .Cases("swprintf", "snprintf", "vswprintf", "vsnprintf", "memcpy", - "memmove", "memset", "strncpy", "strncat", DEPR_ONLY) + .Cases({"scanf", "wscanf", "vscanf", "vwscanf"}, 0) + .Cases({"fscanf", "fwscanf", "vfscanf", "vfwscanf", "sscanf", + "swscanf", "vsscanf", "vswscanf"}, + 1) + .Cases({"sprintf", "vsprintf", "fprintf"}, 1) + .Cases({"swprintf", "snprintf", "vswprintf", "vsnprintf", "memcpy", + "memmove", "memset", "strncpy", "strncat"}, + DEPR_ONLY) .Default(UNKNOWN_CALL); assert(ArgIndex != UNKNOWN_CALL && "Unsupported function"); diff --git a/clang/lib/StaticAnalyzer/Checkers/WebKit/ASTUtils.cpp b/clang/lib/StaticAnalyzer/Checkers/WebKit/ASTUtils.cpp index 66cfccb..c1a5000 100644 --- a/clang/lib/StaticAnalyzer/Checkers/WebKit/ASTUtils.cpp +++ b/clang/lib/StaticAnalyzer/Checkers/WebKit/ASTUtils.cpp @@ -26,6 +26,7 @@ bool tryToFindPtrOrigin( const Expr *E, bool StopAtFirstRefCountedObj, std::function<bool(const clang::CXXRecordDecl *)> isSafePtr, std::function<bool(const clang::QualType)> isSafePtrType, + std::function<bool(const clang::Decl *)> isSafeGlobalDecl, std::function<bool(const clang::Expr *, bool)> callback) { while (E) { if (auto *DRE = dyn_cast<DeclRefExpr>(E)) { @@ -34,6 +35,8 @@ bool tryToFindPtrOrigin( auto IsImmortal = safeGetName(VD) == "NSApp"; if (VD->hasGlobalStorage() && (IsImmortal || QT.isConstQualified())) return callback(E, true); + if (VD->hasGlobalStorage() && isSafeGlobalDecl(VD)) + return callback(E, true); } } if (auto *tempExpr = dyn_cast<MaterializeTemporaryExpr>(E)) { @@ -71,9 +74,11 @@ bool tryToFindPtrOrigin( } if (auto *Expr = dyn_cast<ConditionalOperator>(E)) { return tryToFindPtrOrigin(Expr->getTrueExpr(), StopAtFirstRefCountedObj, - isSafePtr, isSafePtrType, callback) && + isSafePtr, isSafePtrType, isSafeGlobalDecl, + callback) && tryToFindPtrOrigin(Expr->getFalseExpr(), StopAtFirstRefCountedObj, - isSafePtr, isSafePtrType, callback); + isSafePtr, isSafePtrType, isSafeGlobalDecl, + callback); } if (auto *cast = dyn_cast<CastExpr>(E)) { if (StopAtFirstRefCountedObj) { @@ -93,7 +98,8 @@ bool tryToFindPtrOrigin( if (auto *call = dyn_cast<CallExpr>(E)) { if (auto *Callee = call->getCalleeDecl()) { if (Callee->hasAttr<CFReturnsRetainedAttr>() || - Callee->hasAttr<NSReturnsRetainedAttr>()) { + Callee->hasAttr<NSReturnsRetainedAttr>() || + Callee->hasAttr<NSReturnsAutoreleasedAttr>()) { return callback(E, true); } } diff --git a/clang/lib/StaticAnalyzer/Checkers/WebKit/ASTUtils.h b/clang/lib/StaticAnalyzer/Checkers/WebKit/ASTUtils.h index 3a009d6..9fff456 100644 --- a/clang/lib/StaticAnalyzer/Checkers/WebKit/ASTUtils.h +++ b/clang/lib/StaticAnalyzer/Checkers/WebKit/ASTUtils.h @@ -56,6 +56,7 @@ bool tryToFindPtrOrigin( const clang::Expr *E, bool StopAtFirstRefCountedObj, std::function<bool(const clang::CXXRecordDecl *)> isSafePtr, std::function<bool(const clang::QualType)> isSafePtrType, + std::function<bool(const clang::Decl *)> isSafeGlobalDecl, std::function<bool(const clang::Expr *, bool)> callback); /// For \p E referring to a ref-countable/-counted pointer/reference we return diff --git a/clang/lib/StaticAnalyzer/Checkers/WebKit/RawPtrRefCallArgsChecker.cpp b/clang/lib/StaticAnalyzer/Checkers/WebKit/RawPtrRefCallArgsChecker.cpp index 9585ceb..791e709 100644 --- a/clang/lib/StaticAnalyzer/Checkers/WebKit/RawPtrRefCallArgsChecker.cpp +++ b/clang/lib/StaticAnalyzer/Checkers/WebKit/RawPtrRefCallArgsChecker.cpp @@ -29,12 +29,12 @@ namespace { class RawPtrRefCallArgsChecker : public Checker<check::ASTDecl<TranslationUnitDecl>> { BugType Bug; - mutable BugReporter *BR; TrivialFunctionAnalysis TFA; EnsureFunctionAnalysis EFA; protected: + mutable BugReporter *BR; mutable std::optional<RetainTypeChecker> RTC; public: @@ -46,6 +46,7 @@ public: virtual bool isSafePtr(const CXXRecordDecl *Record) const = 0; virtual bool isSafePtrType(const QualType type) const = 0; virtual bool isSafeExpr(const Expr *) const { return false; } + virtual bool isSafeDecl(const Decl *) const { return false; } virtual const char *ptrKind() const = 0; void checkASTDecl(const TranslationUnitDecl *TUD, AnalysisManager &MGR, @@ -214,6 +215,7 @@ public: Arg, /*StopAtFirstRefCountedObj=*/true, [&](const clang::CXXRecordDecl *Record) { return isSafePtr(Record); }, [&](const clang::QualType T) { return isSafePtrType(T); }, + [&](const clang::Decl *D) { return isSafeDecl(D); }, [&](const clang::Expr *ArgOrigin, bool IsSafe) { if (IsSafe) return true; @@ -479,6 +481,11 @@ public: isa<ObjCMessageExpr>(E); } + bool isSafeDecl(const Decl *D) const final { + // Treat NS/CF globals in system header as immortal. + return BR->getSourceManager().isInSystemHeader(D->getLocation()); + } + const char *ptrKind() const final { return "unretained"; } }; diff --git a/clang/lib/StaticAnalyzer/Checkers/WebKit/RawPtrRefLocalVarsChecker.cpp b/clang/lib/StaticAnalyzer/Checkers/WebKit/RawPtrRefLocalVarsChecker.cpp index dd9701f..c13df479 100644 --- a/clang/lib/StaticAnalyzer/Checkers/WebKit/RawPtrRefLocalVarsChecker.cpp +++ b/clang/lib/StaticAnalyzer/Checkers/WebKit/RawPtrRefLocalVarsChecker.cpp @@ -166,10 +166,10 @@ bool isGuardedScopeEmbeddedInGuardianScope(const VarDecl *Guarded, class RawPtrRefLocalVarsChecker : public Checker<check::ASTDecl<TranslationUnitDecl>> { BugType Bug; - mutable BugReporter *BR; EnsureFunctionAnalysis EFA; protected: + mutable BugReporter *BR; mutable std::optional<RetainTypeChecker> RTC; public: @@ -180,6 +180,7 @@ public: virtual bool isSafePtr(const CXXRecordDecl *) const = 0; virtual bool isSafePtrType(const QualType) const = 0; virtual bool isSafeExpr(const Expr *) const { return false; } + virtual bool isSafeDecl(const Decl *) const { return false; } virtual const char *ptrKind() const = 0; void checkASTDecl(const TranslationUnitDecl *TUD, AnalysisManager &MGR, @@ -288,6 +289,7 @@ public: return isSafePtr(Record); }, [&](const clang::QualType Type) { return isSafePtrType(Type); }, + [&](const clang::Decl *D) { return isSafeDecl(D); }, [&](const clang::Expr *InitArgOrigin, bool IsSafe) { if (!InitArgOrigin || IsSafe) return true; @@ -443,6 +445,10 @@ public: return ento::cocoa::isCocoaObjectRef(E->getType()) && isa<ObjCMessageExpr>(E); } + bool isSafeDecl(const Decl *D) const final { + // Treat NS/CF globals in system header as immortal. + return BR->getSourceManager().isInSystemHeader(D->getLocation()); + } const char *ptrKind() const final { return "unretained"; } }; |