ReturnPointerRangeChecker.cpp [plain text]
#include "ClangSACheckers.h"
#include "clang/StaticAnalyzer/Core/Checker.h"
#include "clang/StaticAnalyzer/Core/CheckerManager.h"
#include "clang/StaticAnalyzer/Core/PathSensitive/CheckerContext.h"
#include "clang/StaticAnalyzer/Core/BugReporter/BugType.h"
#include "clang/StaticAnalyzer/Core/PathSensitive/ExprEngine.h"
using namespace clang;
using namespace ento;
namespace {
class ReturnPointerRangeChecker :
public Checker< check::PreStmt<ReturnStmt> > {
mutable OwningPtr<BuiltinBug> BT;
public:
void checkPreStmt(const ReturnStmt *RS, CheckerContext &C) const;
};
}
void ReturnPointerRangeChecker::checkPreStmt(const ReturnStmt *RS,
CheckerContext &C) const {
ProgramStateRef state = C.getState();
const Expr *RetE = RS->getRetValue();
if (!RetE)
return;
SVal V = state->getSVal(RetE, C.getLocationContext());
const MemRegion *R = V.getAsRegion();
const ElementRegion *ER = dyn_cast_or_null<ElementRegion>(R);
if (!ER)
return;
DefinedOrUnknownSVal Idx = cast<DefinedOrUnknownSVal>(ER->getIndex());
if (Idx.isZeroConstant())
return;
DefinedOrUnknownSVal NumElements
= C.getStoreManager().getSizeInElements(state, ER->getSuperRegion(),
ER->getValueType());
ProgramStateRef StInBound = state->assumeInBound(Idx, NumElements, true);
ProgramStateRef StOutBound = state->assumeInBound(Idx, NumElements, false);
if (StOutBound && !StInBound) {
ExplodedNode *N = C.generateSink(StOutBound);
if (!N)
return;
if (!BT)
BT.reset(new BuiltinBug("Return of pointer value outside of expected range",
"Returned pointer value points outside the original object "
"(potential buffer overflow)"));
BugReport *report =
new BugReport(*BT, BT->getDescription(), N);
report->addRange(RetE->getSourceRange());
C.EmitReport(report);
}
}
void ento::registerReturnPointerRangeChecker(CheckerManager &mgr) {
mgr.registerChecker<ReturnPointerRangeChecker>();
}