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authorthegeorg <thegeorg@yandex-team.com>2024-03-13 13:58:24 +0300
committerthegeorg <thegeorg@yandex-team.com>2024-03-13 14:11:53 +0300
commit11a895b7e15d1c5a1f52706396b82e3f9db953cb (patch)
treefabc6d883b0f946151f61ae7865cee9f529a1fdd /contrib/libs/clang16/lib/StaticAnalyzer/Checkers/cert/InvalidPtrChecker.cpp
parent9685917341315774aad5733b1793b1e533a88bbb (diff)
downloadydb-11a895b7e15d1c5a1f52706396b82e3f9db953cb.tar.gz
Export clang-format16 via ydblib project
6e6be3a95868fde888d801b7590af4044049563f
Diffstat (limited to 'contrib/libs/clang16/lib/StaticAnalyzer/Checkers/cert/InvalidPtrChecker.cpp')
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+//== InvalidPtrChecker.cpp ------------------------------------- -*- C++ -*--=//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+//
+// This file defines InvalidPtrChecker which finds usages of possibly
+// invalidated pointer.
+// CERT SEI Rules ENV31-C and ENV34-C
+// For more information see:
+// https://wiki.sei.cmu.edu/confluence/x/8tYxBQ
+// https://wiki.sei.cmu.edu/confluence/x/5NUxBQ
+//===----------------------------------------------------------------------===//
+
+#include "clang/StaticAnalyzer/Checkers/BuiltinCheckerRegistration.h"
+#include "clang/StaticAnalyzer/Core/BugReporter/BugType.h"
+#include "clang/StaticAnalyzer/Core/Checker.h"
+#include "clang/StaticAnalyzer/Core/CheckerManager.h"
+#include "clang/StaticAnalyzer/Core/PathSensitive/CallDescription.h"
+#include "clang/StaticAnalyzer/Core/PathSensitive/CallEvent.h"
+#include "clang/StaticAnalyzer/Core/PathSensitive/CheckerContext.h"
+
+using namespace clang;
+using namespace ento;
+
+namespace {
+
+class InvalidPtrChecker
+ : public Checker<check::Location, check::BeginFunction, check::PostCall> {
+private:
+ BugType BT{this, "Use of invalidated pointer", categories::MemoryError};
+
+ void EnvpInvalidatingCall(const CallEvent &Call, CheckerContext &C) const;
+
+ using HandlerFn = void (InvalidPtrChecker::*)(const CallEvent &Call,
+ CheckerContext &C) const;
+
+ // SEI CERT ENV31-C
+ const CallDescriptionMap<HandlerFn> EnvpInvalidatingFunctions = {
+ {{{"setenv"}, 3}, &InvalidPtrChecker::EnvpInvalidatingCall},
+ {{{"unsetenv"}, 1}, &InvalidPtrChecker::EnvpInvalidatingCall},
+ {{{"putenv"}, 1}, &InvalidPtrChecker::EnvpInvalidatingCall},
+ {{{"_putenv_s"}, 2}, &InvalidPtrChecker::EnvpInvalidatingCall},
+ {{{"_wputenv_s"}, 2}, &InvalidPtrChecker::EnvpInvalidatingCall},
+ };
+
+ void postPreviousReturnInvalidatingCall(const CallEvent &Call,
+ CheckerContext &C) const;
+
+ // SEI CERT ENV34-C
+ const CallDescriptionMap<HandlerFn> PreviousCallInvalidatingFunctions = {
+ {{{"getenv"}, 1}, &InvalidPtrChecker::postPreviousReturnInvalidatingCall},
+ {{{"setlocale"}, 2},
+ &InvalidPtrChecker::postPreviousReturnInvalidatingCall},
+ {{{"strerror"}, 1},
+ &InvalidPtrChecker::postPreviousReturnInvalidatingCall},
+ {{{"localeconv"}, 0},
+ &InvalidPtrChecker::postPreviousReturnInvalidatingCall},
+ {{{"asctime"}, 1},
+ &InvalidPtrChecker::postPreviousReturnInvalidatingCall},
+ };
+
+public:
+ // Obtain the environment pointer from 'main()' (if present).
+ void checkBeginFunction(CheckerContext &C) const;
+
+ // Handle functions in EnvpInvalidatingFunctions, that invalidate environment
+ // pointer from 'main()'
+ // Handle functions in PreviousCallInvalidatingFunctions.
+ // Also, check if invalidated region is passed to a
+ // conservatively evaluated function call as an argument.
+ void checkPostCall(const CallEvent &Call, CheckerContext &C) const;
+
+ // Check if invalidated region is being dereferenced.
+ void checkLocation(SVal l, bool isLoad, const Stmt *S,
+ CheckerContext &C) const;
+};
+
+} // namespace
+
+// Set of memory regions that were invalidated
+REGISTER_SET_WITH_PROGRAMSTATE(InvalidMemoryRegions, const MemRegion *)
+
+// Stores the region of the environment pointer of 'main' (if present).
+REGISTER_TRAIT_WITH_PROGRAMSTATE(EnvPtrRegion, const MemRegion *)
+
+// Stores key-value pairs, where key is function declaration and value is
+// pointer to memory region returned by previous call of this function
+REGISTER_MAP_WITH_PROGRAMSTATE(PreviousCallResultMap, const FunctionDecl *,
+ const MemRegion *)
+
+void InvalidPtrChecker::EnvpInvalidatingCall(const CallEvent &Call,
+ CheckerContext &C) const {
+ StringRef FunctionName = Call.getCalleeIdentifier()->getName();
+ ProgramStateRef State = C.getState();
+ const MemRegion *SymbolicEnvPtrRegion = State->get<EnvPtrRegion>();
+ if (!SymbolicEnvPtrRegion)
+ return;
+
+ State = State->add<InvalidMemoryRegions>(SymbolicEnvPtrRegion);
+
+ const NoteTag *Note =
+ C.getNoteTag([SymbolicEnvPtrRegion, FunctionName](
+ PathSensitiveBugReport &BR, llvm::raw_ostream &Out) {
+ if (!BR.isInteresting(SymbolicEnvPtrRegion))
+ return;
+ Out << '\'' << FunctionName
+ << "' call may invalidate the environment parameter of 'main'";
+ });
+
+ C.addTransition(State, Note);
+}
+
+void InvalidPtrChecker::postPreviousReturnInvalidatingCall(
+ const CallEvent &Call, CheckerContext &C) const {
+ ProgramStateRef State = C.getState();
+
+ const NoteTag *Note = nullptr;
+ const FunctionDecl *FD = dyn_cast_or_null<FunctionDecl>(Call.getDecl());
+ // Invalidate the region of the previously returned pointer - if there was
+ // one.
+ if (const MemRegion *const *Reg = State->get<PreviousCallResultMap>(FD)) {
+ const MemRegion *PrevReg = *Reg;
+ State = State->add<InvalidMemoryRegions>(PrevReg);
+ Note = C.getNoteTag([PrevReg, FD](PathSensitiveBugReport &BR,
+ llvm::raw_ostream &Out) {
+ if (!BR.isInteresting(PrevReg))
+ return;
+ Out << '\'';
+ FD->getNameForDiagnostic(Out, FD->getASTContext().getLangOpts(), true);
+ Out << "' call may invalidate the result of the previous " << '\'';
+ FD->getNameForDiagnostic(Out, FD->getASTContext().getLangOpts(), true);
+ Out << '\'';
+ });
+ }
+
+ const LocationContext *LCtx = C.getLocationContext();
+ const auto *CE = cast<CallExpr>(Call.getOriginExpr());
+
+ // Function call will return a pointer to the new symbolic region.
+ DefinedOrUnknownSVal RetVal = C.getSValBuilder().conjureSymbolVal(
+ CE, LCtx, CE->getType(), C.blockCount());
+ State = State->BindExpr(CE, LCtx, RetVal);
+
+ // Remember to this region.
+ const auto *SymRegOfRetVal = cast<SymbolicRegion>(RetVal.getAsRegion());
+ const MemRegion *MR =
+ const_cast<MemRegion *>(SymRegOfRetVal->getBaseRegion());
+ State = State->set<PreviousCallResultMap>(FD, MR);
+
+ ExplodedNode *Node = C.addTransition(State, Note);
+ const NoteTag *PreviousCallNote =
+ C.getNoteTag([MR](PathSensitiveBugReport &BR, llvm::raw_ostream &Out) {
+ if (!BR.isInteresting(MR))
+ return;
+ Out << '\'' << "'previous function call was here" << '\'';
+ });
+
+ C.addTransition(State, Node, PreviousCallNote);
+}
+
+// TODO: This seems really ugly. Simplify this.
+static const MemRegion *findInvalidatedSymbolicBase(ProgramStateRef State,
+ const MemRegion *Reg) {
+ while (Reg) {
+ if (State->contains<InvalidMemoryRegions>(Reg))
+ return Reg;
+ const auto *SymBase = Reg->getSymbolicBase();
+ if (!SymBase)
+ break;
+ const auto *SRV = dyn_cast<SymbolRegionValue>(SymBase->getSymbol());
+ if (!SRV)
+ break;
+ Reg = SRV->getRegion();
+ if (const auto *VarReg = dyn_cast<VarRegion>(SRV->getRegion()))
+ Reg = VarReg;
+ }
+ return nullptr;
+}
+
+// Handle functions in EnvpInvalidatingFunctions, that invalidate environment
+// pointer from 'main()' Also, check if invalidated region is passed to a
+// function call as an argument.
+void InvalidPtrChecker::checkPostCall(const CallEvent &Call,
+ CheckerContext &C) const {
+ // Check if function invalidates 'envp' argument of 'main'
+ if (const auto *Handler = EnvpInvalidatingFunctions.lookup(Call))
+ (this->**Handler)(Call, C);
+
+ // Check if function invalidates the result of previous call
+ if (const auto *Handler = PreviousCallInvalidatingFunctions.lookup(Call))
+ (this->**Handler)(Call, C);
+
+ // Check if one of the arguments of the function call is invalidated
+
+ // If call was inlined, don't report invalidated argument
+ if (C.wasInlined)
+ return;
+
+ ProgramStateRef State = C.getState();
+
+ for (unsigned I = 0, NumArgs = Call.getNumArgs(); I < NumArgs; ++I) {
+
+ if (const auto *SR = dyn_cast_or_null<SymbolicRegion>(
+ Call.getArgSVal(I).getAsRegion())) {
+ if (const MemRegion *InvalidatedSymbolicBase =
+ findInvalidatedSymbolicBase(State, SR)) {
+ ExplodedNode *ErrorNode = C.generateNonFatalErrorNode();
+ if (!ErrorNode)
+ return;
+
+ SmallString<256> Msg;
+ llvm::raw_svector_ostream Out(Msg);
+ Out << "use of invalidated pointer '";
+ Call.getArgExpr(I)->printPretty(Out, /*Helper=*/nullptr,
+ C.getASTContext().getPrintingPolicy());
+ Out << "' in a function call";
+
+ auto Report =
+ std::make_unique<PathSensitiveBugReport>(BT, Out.str(), ErrorNode);
+ Report->markInteresting(InvalidatedSymbolicBase);
+ Report->addRange(Call.getArgSourceRange(I));
+ C.emitReport(std::move(Report));
+ }
+ }
+ }
+}
+
+// Obtain the environment pointer from 'main()', if present.
+void InvalidPtrChecker::checkBeginFunction(CheckerContext &C) const {
+ if (!C.inTopFrame())
+ return;
+
+ const auto *FD = dyn_cast<FunctionDecl>(C.getLocationContext()->getDecl());
+ if (!FD || FD->param_size() != 3 || !FD->isMain())
+ return;
+
+ ProgramStateRef State = C.getState();
+ const MemRegion *EnvpReg =
+ State->getRegion(FD->parameters()[2], C.getLocationContext());
+
+ // Save the memory region pointed by the environment pointer parameter of
+ // 'main'.
+ C.addTransition(State->set<EnvPtrRegion>(EnvpReg));
+}
+
+// Check if invalidated region is being dereferenced.
+void InvalidPtrChecker::checkLocation(SVal Loc, bool isLoad, const Stmt *S,
+ CheckerContext &C) const {
+ ProgramStateRef State = C.getState();
+
+ // Ignore memory operations involving 'non-invalidated' locations.
+ const MemRegion *InvalidatedSymbolicBase =
+ findInvalidatedSymbolicBase(State, Loc.getAsRegion());
+ if (!InvalidatedSymbolicBase)
+ return;
+
+ ExplodedNode *ErrorNode = C.generateNonFatalErrorNode();
+ if (!ErrorNode)
+ return;
+
+ auto Report = std::make_unique<PathSensitiveBugReport>(
+ BT, "dereferencing an invalid pointer", ErrorNode);
+ Report->markInteresting(InvalidatedSymbolicBase);
+ C.emitReport(std::move(Report));
+}
+
+void ento::registerInvalidPtrChecker(CheckerManager &Mgr) {
+ Mgr.registerChecker<InvalidPtrChecker>();
+}
+
+bool ento::shouldRegisterInvalidPtrChecker(const CheckerManager &) {
+ return true;
+}