| 1 | //== PutenvWithAutoChecker.cpp --------------------------------- -*- C++ -*--=// |
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| 2 | // |
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| 3 | // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. |
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| 4 | // See https://llvm.org/LICENSE.txt for license information. |
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| 5 | // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception |
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| 6 | // |
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| 7 | //===----------------------------------------------------------------------===// |
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| 8 | // |
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| 9 | // This file defines PutenvWithAutoChecker which finds calls of ``putenv`` |
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| 10 | // function with automatic variable as the argument. |
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| 11 | // https://wiki.sei.cmu.edu/confluence/x/6NYxBQ |
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| 12 | // |
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| 13 | //===----------------------------------------------------------------------===// |
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| 14 | |
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| 15 | #include "../AllocationState.h" |
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| 16 | #include "clang/StaticAnalyzer/Checkers/BuiltinCheckerRegistration.h" |
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| 17 | #include "clang/StaticAnalyzer/Core/BugReporter/BugType.h" |
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| 18 | #include "clang/StaticAnalyzer/Core/Checker.h" |
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| 19 | #include "clang/StaticAnalyzer/Core/CheckerManager.h" |
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| 20 | #include "clang/StaticAnalyzer/Core/PathSensitive/CallDescription.h" |
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| 21 | #include "clang/StaticAnalyzer/Core/PathSensitive/CallEvent.h" |
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| 22 | #include "clang/StaticAnalyzer/Core/PathSensitive/CheckerContext.h" |
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| 23 | #include "clang/StaticAnalyzer/Core/PathSensitive/MemRegion.h" |
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| 24 | |
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| 25 | using namespace clang; |
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| 26 | using namespace ento; |
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| 27 | |
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| 28 | namespace { |
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| 29 | class PutenvWithAutoChecker : public Checker<check::PostCall> { |
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| 30 | private: |
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| 31 | BugType BT{this, "'putenv' function should not be called with auto variables" , |
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| 32 | categories::SecurityError}; |
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| 33 | const CallDescription Putenv{CDM::CLibrary, {"putenv" }, 1}; |
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| 34 | |
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| 35 | public: |
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| 36 | void checkPostCall(const CallEvent &Call, CheckerContext &C) const; |
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| 37 | }; |
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| 38 | } // namespace |
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| 39 | |
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| 40 | void PutenvWithAutoChecker::checkPostCall(const CallEvent &Call, |
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| 41 | CheckerContext &C) const { |
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| 42 | if (!Putenv.matches(Call)) |
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| 43 | return; |
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| 44 | |
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| 45 | SVal ArgV = Call.getArgSVal(Index: 0); |
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| 46 | const Expr *ArgExpr = Call.getArgExpr(Index: 0); |
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| 47 | const MemSpaceRegion *MSR = ArgV.getAsRegion()->getMemorySpace(); |
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| 48 | |
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| 49 | if (!isa<StackSpaceRegion>(Val: MSR)) |
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| 50 | return; |
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| 51 | |
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| 52 | StringRef ErrorMsg = "The 'putenv' function should not be called with " |
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| 53 | "arguments that have automatic storage" ; |
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| 54 | ExplodedNode *N = C.generateErrorNode(); |
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| 55 | auto Report = std::make_unique<PathSensitiveBugReport>(args: BT, args&: ErrorMsg, args&: N); |
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| 56 | |
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| 57 | // Track the argument. |
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| 58 | bugreporter::trackExpressionValue(N: Report->getErrorNode(), E: ArgExpr, R&: *Report); |
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| 59 | |
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| 60 | C.emitReport(R: std::move(Report)); |
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| 61 | } |
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| 62 | |
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| 63 | void ento::registerPutenvWithAuto(CheckerManager &Mgr) { |
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| 64 | Mgr.registerChecker<PutenvWithAutoChecker>(); |
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| 65 | } |
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| 66 | |
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| 67 | bool ento::shouldRegisterPutenvWithAuto(const CheckerManager &) { return true; } |
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| 68 | |
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