168 lines
6.6 KiB
C++
168 lines
6.6 KiB
C++
/*
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* Cppcheck - A tool for static C/C++ code analysis
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* Copyright (C) 2007-2022 Cppcheck team.
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*
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* This program is free software: you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation, either version 3 of the License, or
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* (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program. If not, see <http://www.gnu.org/licenses/>.
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*/
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//---------------------------------------------------------------------------
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#ifndef checkbufferoverrunH
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#define checkbufferoverrunH
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//---------------------------------------------------------------------------
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#include "check.h"
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#include "config.h"
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#include "ctu.h"
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#include "errortypes.h"
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#include "mathlib.h"
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#include "symboldatabase.h"
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#include "valueflow.h"
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#include <list>
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#include <map>
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#include <string>
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#include <vector>
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namespace tinyxml2 {
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class XMLElement;
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}
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class ErrorLogger;
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class Settings;
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class Token;
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class Tokenizer;
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/// @addtogroup Checks
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/// @{
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/**
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* @brief buffer overruns and array index out of bounds
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*
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* Buffer overrun and array index out of bounds are pretty much the same.
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* But I generally use 'array index' if the code contains []. And the given
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* index is out of bounds.
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* I generally use 'buffer overrun' if you for example call a strcpy or
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* other function and pass a buffer and reads or writes too much data.
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*/
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class CPPCHECKLIB CheckBufferOverrun : public Check {
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public:
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/** This constructor is used when registering the CheckClass */
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CheckBufferOverrun() : Check(myName()) {}
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/** This constructor is used when running checks. */
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CheckBufferOverrun(const Tokenizer *tokenizer, const Settings *settings, ErrorLogger *errorLogger)
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: Check(myName(), tokenizer, settings, errorLogger) {}
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void runChecks(const Tokenizer *tokenizer, const Settings *settings, ErrorLogger *errorLogger) override {
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CheckBufferOverrun checkBufferOverrun(tokenizer, settings, errorLogger);
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checkBufferOverrun.arrayIndex();
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checkBufferOverrun.pointerArithmetic();
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checkBufferOverrun.bufferOverflow();
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checkBufferOverrun.arrayIndexThenCheck();
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checkBufferOverrun.stringNotZeroTerminated();
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checkBufferOverrun.objectIndex();
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checkBufferOverrun.argumentSize();
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}
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void getErrorMessages(ErrorLogger *errorLogger, const Settings *settings) const override {
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CheckBufferOverrun c(nullptr, settings, errorLogger);
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c.arrayIndexError(nullptr, std::vector<Dimension>(), std::vector<ValueFlow::Value>());
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c.pointerArithmeticError(nullptr, nullptr, nullptr);
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c.negativeIndexError(nullptr, std::vector<Dimension>(), std::vector<ValueFlow::Value>());
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c.arrayIndexThenCheckError(nullptr, "i");
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c.bufferOverflowError(nullptr, nullptr, Certainty::normal);
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c.objectIndexError(nullptr, nullptr, true);
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c.argumentSizeError(nullptr, "function", 1, "buffer", nullptr, nullptr);
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}
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/** @brief Parse current TU and extract file info */
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Check::FileInfo *getFileInfo(const Tokenizer *tokenizer, const Settings *settings) const override;
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/** @brief Analyse all file infos for all TU */
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bool analyseWholeProgram(const CTU::FileInfo *ctu, const std::list<Check::FileInfo*> &fileInfo, const Settings& settings, ErrorLogger &errorLogger) override;
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private:
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void arrayIndex();
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void arrayIndexError(const Token* tok,
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const std::vector<Dimension>& dimensions,
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const std::vector<ValueFlow::Value>& indexes);
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void negativeIndexError(const Token* tok,
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const std::vector<Dimension>& dimensions,
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const std::vector<ValueFlow::Value>& indexes);
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void pointerArithmetic();
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void pointerArithmeticError(const Token *tok, const Token *indexToken, const ValueFlow::Value *indexValue);
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void bufferOverflow();
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void bufferOverflowError(const Token *tok, const ValueFlow::Value *value, const Certainty::CertaintyLevel& certainty);
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void arrayIndexThenCheck();
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void arrayIndexThenCheckError(const Token *tok, const std::string &indexName);
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void stringNotZeroTerminated();
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void terminateStrncpyError(const Token *tok, const std::string &varname);
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void argumentSize();
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void argumentSizeError(const Token *tok, const std::string &functionName, nonneg int paramIndex, const std::string ¶mExpression, const Variable *paramVar, const Variable *functionArg);
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void objectIndex();
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void objectIndexError(const Token *tok, const ValueFlow::Value *v, bool known);
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ValueFlow::Value getBufferSize(const Token *bufTok) const;
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// CTU
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/** data for multifile checking */
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class MyFileInfo : public Check::FileInfo {
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public:
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/** unsafe array index usage */
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std::list<CTU::FileInfo::UnsafeUsage> unsafeArrayIndex;
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/** unsafe pointer arithmetics */
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std::list<CTU::FileInfo::UnsafeUsage> unsafePointerArith;
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/** Convert MyFileInfo data into xml string */
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std::string toString() const override;
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};
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static bool isCtuUnsafeBufferUsage(const Check *check, const Token *argtok, MathLib::bigint *offset, int type);
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static bool isCtuUnsafeArrayIndex(const Check *check, const Token *argtok, MathLib::bigint *offset);
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static bool isCtuUnsafePointerArith(const Check *check, const Token *argtok, MathLib::bigint *offset);
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Check::FileInfo * loadFileInfoFromXml(const tinyxml2::XMLElement *xmlElement) const override;
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static bool analyseWholeProgram1(const std::map<std::string, std::list<const CTU::FileInfo::CallBase *>> &callsMap, const CTU::FileInfo::UnsafeUsage &unsafeUsage, int type, ErrorLogger &errorLogger);
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static std::string myName() {
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return "Bounds checking";
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}
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std::string classInfo() const override {
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return "Out of bounds checking:\n"
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"- Array index out of bounds\n"
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"- Pointer arithmetic overflow\n"
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"- Buffer overflow\n"
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"- Dangerous usage of strncat()\n"
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"- Using array index before checking it\n"
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"- Partial string write that leads to buffer that is not zero terminated.\n"
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"- Check for large enough arrays being passed to functions\n";
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}
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};
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/// @}
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//---------------------------------------------------------------------------
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#endif // checkbufferoverrunH
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