//===----------------------------------------------------------------------===//
#include "Taint.h"
-#include "clang/StaticAnalyzer/Checkers/BuiltinCheckerRegistration.h"
+#include "Yaml.h"
#include "clang/AST/Attr.h"
#include "clang/Basic/Builtins.h"
+#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/CheckerContext.h"
#include "clang/StaticAnalyzer/Core/PathSensitive/ProgramStateTrait.h"
-#include <climits>
-#include <initializer_list>
+#include "llvm/ADT/StringMap.h"
+#include "llvm/Support/YAMLTraits.h"
+#include <limits>
#include <utility>
using namespace clang;
void checkPreStmt(const CallExpr *CE, CheckerContext &C) const;
- void printState(raw_ostream &Out, ProgramStateRef State,
- const char *NL, const char *Sep) const override;
+ void printState(raw_ostream &Out, ProgramStateRef State, const char *NL,
+ const char *Sep) const override;
-private:
- static const unsigned InvalidArgIndex = UINT_MAX;
+ using ArgVector = SmallVector<unsigned, 2>;
+ using SignedArgVector = SmallVector<int, 2>;
+
+ enum class VariadicType { None, Src, Dst };
+
+ /// Used to parse the configuration file.
+ struct TaintConfiguration {
+ using NameArgsPair = std::pair<std::string, ArgVector>;
+
+ struct Propagation {
+ std::string Name;
+ ArgVector SrcArgs;
+ SignedArgVector DstArgs;
+ VariadicType VarType;
+ unsigned VarIndex;
+ };
+
+ std::vector<Propagation> Propagations;
+ std::vector<NameArgsPair> Filters;
+ std::vector<NameArgsPair> Sinks;
+
+ TaintConfiguration() = default;
+ TaintConfiguration(const TaintConfiguration &) = delete;
+ TaintConfiguration(TaintConfiguration &&) = default;
+ TaintConfiguration &operator=(const TaintConfiguration &) = delete;
+ TaintConfiguration &operator=(TaintConfiguration &&) = default;
+ };
+
+ /// Convert SignedArgVector to ArgVector.
+ ArgVector convertToArgVector(CheckerManager &Mgr, const std::string &Option,
+ SignedArgVector Args);
+
+ /// Parse the config.
+ void parseConfiguration(CheckerManager &Mgr, const std::string &Option,
+ TaintConfiguration &&Config);
+
+ static const unsigned InvalidArgIndex{std::numeric_limits<unsigned>::max()};
/// Denotes the return vale.
- static const unsigned ReturnValueIndex = UINT_MAX - 1;
+ static const unsigned ReturnValueIndex{std::numeric_limits<unsigned>::max() -
+ 1};
+private:
mutable std::unique_ptr<BugType> BT;
void initBugType() const {
if (!BT)
bool generateReportIfTainted(const Expr *E, const char Msg[],
CheckerContext &C) const;
- using ArgVector = SmallVector<unsigned, 2>;
-
/// A struct used to specify taint propagation rules for a function.
///
/// If any of the possible taint source arguments is tainted, all of the
/// ReturnValueIndex is added to the dst list, the return value will be
/// tainted.
struct TaintPropagationRule {
- enum class VariadicType { None, Src, Dst };
-
using PropagationFuncType = bool (*)(bool IsTainted, const CallExpr *,
CheckerContext &C);
: VariadicIndex(InvalidArgIndex), VarType(VariadicType::None),
PropagationFunc(nullptr) {}
- TaintPropagationRule(std::initializer_list<unsigned> &&Src,
- std::initializer_list<unsigned> &&Dst,
+ TaintPropagationRule(ArgVector &&Src, ArgVector &&Dst,
VariadicType Var = VariadicType::None,
unsigned VarIndex = InvalidArgIndex,
PropagationFuncType Func = nullptr)
static bool postSocket(bool IsTainted, const CallExpr *CE,
CheckerContext &C);
};
+
+ using NameRuleMap = llvm::StringMap<TaintPropagationRule>;
+ using NameArgMap = llvm::StringMap<ArgVector>;
+
+ /// Defines a map between the propagation function's name and
+ /// TaintPropagationRule.
+ NameRuleMap CustomPropagations;
+
+ /// Defines a map between the filter function's name and filtering args.
+ NameArgMap CustomFilters;
+
+ /// Defines a map between the sink function's name and sinking args.
+ NameArgMap CustomSinks;
};
const unsigned GenericTaintChecker::ReturnValueIndex;
"Untrusted data is used to specify the buffer size "
"(CERT/STR31-C. Guarantee that storage for strings has sufficient space "
"for character data and the null terminator)";
-
} // end of anonymous namespace
+using TaintConfig = GenericTaintChecker::TaintConfiguration;
+
+LLVM_YAML_IS_SEQUENCE_VECTOR(TaintConfig::Propagation)
+LLVM_YAML_IS_SEQUENCE_VECTOR(TaintConfig::NameArgsPair)
+
+namespace llvm {
+namespace yaml {
+template <> struct MappingTraits<TaintConfig> {
+ static void mapping(IO &IO, TaintConfig &Config) {
+ IO.mapOptional("Propagations", Config.Propagations);
+ IO.mapOptional("Filters", Config.Filters);
+ IO.mapOptional("Sinks", Config.Sinks);
+ }
+};
+
+template <> struct MappingTraits<TaintConfig::Propagation> {
+ static void mapping(IO &IO, TaintConfig::Propagation &Propagation) {
+ IO.mapRequired("Name", Propagation.Name);
+ IO.mapOptional("SrcArgs", Propagation.SrcArgs);
+ IO.mapOptional("DstArgs", Propagation.DstArgs);
+ IO.mapOptional("VariadicType", Propagation.VarType,
+ GenericTaintChecker::VariadicType::None);
+ IO.mapOptional("VariadicIndex", Propagation.VarIndex,
+ GenericTaintChecker::InvalidArgIndex);
+ }
+};
+
+template <> struct ScalarEnumerationTraits<GenericTaintChecker::VariadicType> {
+ static void enumeration(IO &IO, GenericTaintChecker::VariadicType &Value) {
+ IO.enumCase(Value, "None", GenericTaintChecker::VariadicType::None);
+ IO.enumCase(Value, "Src", GenericTaintChecker::VariadicType::Src);
+ IO.enumCase(Value, "Dst", GenericTaintChecker::VariadicType::Dst);
+ }
+};
+
+template <> struct MappingTraits<TaintConfig::NameArgsPair> {
+ static void mapping(IO &IO, TaintConfig::NameArgsPair &NameArg) {
+ IO.mapRequired("Name", NameArg.first);
+ IO.mapRequired("Args", NameArg.second);
+ }
+};
+} // namespace yaml
+} // namespace llvm
+
/// A set which is used to pass information from call pre-visit instruction
/// to the call post-visit. The values are unsigned integers, which are either
/// ReturnValueIndex, or indexes of the pointer/reference argument, which
/// points to data, which should be tainted on return.
REGISTER_SET_WITH_PROGRAMSTATE(TaintArgsOnPostVisit, unsigned)
+GenericTaintChecker::ArgVector GenericTaintChecker::convertToArgVector(
+ CheckerManager &Mgr, const std::string &Option, SignedArgVector Args) {
+ ArgVector Result;
+ for (int Arg : Args) {
+ if (Arg == -1)
+ Result.push_back(ReturnValueIndex);
+ else if (Arg < -1) {
+ Result.push_back(InvalidArgIndex);
+ Mgr.reportInvalidCheckerOptionValue(
+ this, Option,
+ "an argument number for propagation rules greater or equal to -1");
+ } else
+ Result.push_back(static_cast<unsigned>(Arg));
+ }
+ return Result;
+}
+
+void GenericTaintChecker::parseConfiguration(CheckerManager &Mgr,
+ const std::string &Option,
+ TaintConfiguration &&Config) {
+ for (auto &P : Config.Propagations) {
+ GenericTaintChecker::CustomPropagations.try_emplace(
+ P.Name, std::move(P.SrcArgs),
+ convertToArgVector(Mgr, Option, P.DstArgs), P.VarType, P.VarIndex);
+ }
+
+ for (auto &F : Config.Filters) {
+ GenericTaintChecker::CustomFilters.try_emplace(F.first,
+ std::move(F.second));
+ }
+
+ for (auto &S : Config.Sinks) {
+ GenericTaintChecker::CustomSinks.try_emplace(S.first, std::move(S.second));
+ }
+}
+
GenericTaintChecker::TaintPropagationRule
GenericTaintChecker::TaintPropagationRule::getTaintPropagationRule(
const FunctionDecl *FDecl, StringRef Name, CheckerContext &C) {
.Case("freopen", TaintPropagationRule({}, {ReturnValueIndex}))
.Case("getch", TaintPropagationRule({}, {ReturnValueIndex}))
.Case("getchar", TaintPropagationRule({}, {ReturnValueIndex}))
- .Case("getchar_unlocked", TaintPropagationRule({}, {ReturnValueIndex}))
+ .Case("getchar_unlocked",
+ TaintPropagationRule({}, {ReturnValueIndex}))
.Case("getenv", TaintPropagationRule({}, {ReturnValueIndex}))
.Case("gets", TaintPropagationRule({}, {0, ReturnValueIndex}))
.Case("scanf", TaintPropagationRule({}, {}, VariadicType::Dst, 1))
// Check for taint in variadic arguments.
if (!IsTainted && VariadicType::Src == VarType) {
// Check if any of the arguments is tainted
- for (unsigned int i = VariadicIndex; i < CE->getNumArgs(); ++i) {
+ for (unsigned i = VariadicIndex; i < CE->getNumArgs(); ++i) {
if ((IsTainted = isTaintedOrPointsToTainted(CE->getArg(i), State, C)))
break;
}
// If they are not pointing to const data, mark data as tainted.
// TODO: So far we are just going one level down; ideally we'd need to
// recurse here.
- for (unsigned int i = VariadicIndex; i < CE->getNumArgs(); ++i) {
+ for (unsigned i = VariadicIndex; i < CE->getNumArgs(); ++i) {
const Expr *Arg = CE->getArg(i);
// Process pointer argument.
const Type *ArgTy = Arg->getType().getTypePtr();
static bool getPrintfFormatArgumentNum(const CallExpr *CE,
const CheckerContext &C,
- unsigned int &ArgNum) {
+ unsigned &ArgNum) {
// Find if the function contains a format string argument.
// Handles: fprintf, printf, sprintf, snprintf, vfprintf, vprintf, vsprintf,
// vsnprintf, syslog, custom annotated functions.
bool GenericTaintChecker::checkUncontrolledFormatString(
const CallExpr *CE, CheckerContext &C) const {
// Check if the function contains a format string argument.
- unsigned int ArgNum = 0;
+ unsigned ArgNum = 0;
if (!getPrintfFormatArgumentNum(CE, C, ArgNum))
return false;
generateReportIfTainted(CE->getArg(ArgNum), MsgTaintedBufferSize, C);
}
-void ento::registerGenericTaintChecker(CheckerManager &mgr) {
- mgr.registerChecker<GenericTaintChecker>();
+void ento::registerGenericTaintChecker(CheckerManager &Mgr) {
+ auto *Checker = Mgr.registerChecker<GenericTaintChecker>();
+ std::string Option{"Config"};
+ StringRef ConfigFile =
+ Mgr.getAnalyzerOptions().getCheckerStringOption(Checker, Option);
+ llvm::Optional<TaintConfig> Config =
+ getConfiguration<TaintConfig>(Mgr, Checker, Option, ConfigFile);
+ if (Config)
+ Checker->parseConfiguration(Mgr, Option, std::move(Config).getValue());
}
bool ento::shouldRegisterGenericTaintChecker(const LangOptions &LO) {
-// RUN: %clang_analyze_cc1 -analyzer-checker=alpha.security.taint,core,alpha.security.ArrayBoundV2 -Wno-format-security -verify %s
-// RUN: %clang_analyze_cc1 -DFILE_IS_STRUCT -analyzer-checker=alpha.security.taint,core,alpha.security.ArrayBoundV2 -Wno-format-security -verify %s
+// RUN: %clang_analyze_cc1 -Wno-format-security -verify %s \
+// RUN: -analyzer-checker=alpha.security.taint \
+// RUN: -analyzer-checker=core \
+// RUN: -analyzer-checker=alpha.security.ArrayBoundV2 \
+// RUN: -analyzer-config \
+// RUN: alpha.security.taint.TaintPropagation:Config=%S/Inputs/taint-generic-config.yaml
+
+// RUN: %clang_analyze_cc1 -Wno-format-security -verify %s \
+// RUN: -DFILE_IS_STRUCT \
+// RUN: -analyzer-checker=alpha.security.taint \
+// RUN: -analyzer-checker=core \
+// RUN: -analyzer-checker=alpha.security.ArrayBoundV2 \
+// RUN: -analyzer-config \
+// RUN: alpha.security.taint.TaintPropagation:Config=%S/Inputs/taint-generic-config.yaml
+
+// RUN: not %clang_analyze_cc1 -verify %s \
+// RUN: -analyzer-checker=alpha.security.taint \
+// RUN: -analyzer-config \
+// RUN: alpha.security.taint.TaintPropagation:Config=justguessit \
+// RUN: 2>&1 | FileCheck %s -check-prefix=CHECK-INVALID-FILE
+
+// CHECK-INVALID-FILE: (frontend): invalid input for checker option
+// CHECK-INVALID-FILE-SAME: 'alpha.security.taint.TaintPropagation:Config',
+// CHECK-INVALID-FILE-SAME: that expects a valid filename instead of
+// CHECK-INVALID-FILE-SAME: 'justguessit'
+
+// RUN: not %clang_analyze_cc1 -verify %s \
+// RUN: -analyzer-checker=alpha.security.taint \
+// RUN: -analyzer-config \
+// RUN: alpha.security.taint.TaintPropagation:Config=%S/Inputs/taint-generic-config-ill-formed.yaml \
+// RUN: 2>&1 | FileCheck %s -check-prefix=CHECK-ILL-FORMED
+
+// CHECK-ILL-FORMED: (frontend): invalid input for checker option
+// CHECK-ILL-FORMED-SAME: 'alpha.security.taint.TaintPropagation:Config',
+// CHECK-ILL-FORMED-SAME: that expects a valid yaml file: Invalid argument
+
+// RUN: not %clang_analyze_cc1 -verify %s \
+// RUN: -analyzer-checker=alpha.security.taint \
+// RUN: -analyzer-config \
+// RUN: alpha.security.taint.TaintPropagation:Config=%S/Inputs/taint-generic-config-invalid-arg.yaml \
+// RUN: 2>&1 | FileCheck %s -check-prefix=CHECK-INVALID-ARG
+
+// CHECK-INVALID-ARG: (frontend): invalid input for checker option
+// CHECK-INVALID-ARG-SAME: 'alpha.security.taint.TaintPropagation:Config',
+// CHECK-INVALID-ARG-SAME: that expects an argument number for propagation
+// CHECK-INVALID-ARG-SAME: rules greater or equal to -1
int scanf(const char *restrict format, ...);
char *gets(char *str);