You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
628 lines
23 KiB
628 lines
23 KiB
//===- FuzzerTraceState.cpp - Trace-based fuzzer mutator ------------------===//
|
|
//
|
|
// The LLVM Compiler Infrastructure
|
|
//
|
|
// This file is distributed under the University of Illinois Open Source
|
|
// License. See LICENSE.TXT for details.
|
|
//
|
|
//===----------------------------------------------------------------------===//
|
|
// This file implements a mutation algorithm based on instruction traces and
|
|
// on taint analysis feedback from DFSan.
|
|
//
|
|
// Instruction traces are special hooks inserted by the compiler around
|
|
// interesting instructions. Currently supported traces:
|
|
// * __sanitizer_cov_trace_cmp -- inserted before every ICMP instruction,
|
|
// receives the type, size and arguments of ICMP.
|
|
//
|
|
// Every time a traced event is intercepted we analyse the data involved
|
|
// in the event and suggest a mutation for future executions.
|
|
// For example if 4 bytes of data that derive from input bytes {4,5,6,7}
|
|
// are compared with a constant 12345,
|
|
// we try to insert 12345, 12344, 12346 into bytes
|
|
// {4,5,6,7} of the next fuzzed inputs.
|
|
//
|
|
// The fuzzer can work only with the traces, or with both traces and DFSan.
|
|
//
|
|
// DataFlowSanitizer (DFSan) is a tool for
|
|
// generalised dynamic data flow (taint) analysis:
|
|
// http://clang.llvm.org/docs/DataFlowSanitizer.html .
|
|
//
|
|
// The approach with DFSan-based fuzzing has some similarity to
|
|
// "Taint-based Directed Whitebox Fuzzing"
|
|
// by Vijay Ganesh & Tim Leek & Martin Rinard:
|
|
// http://dspace.mit.edu/openaccess-disseminate/1721.1/59320,
|
|
// but it uses a full blown LLVM IR taint analysis and separate instrumentation
|
|
// to analyze all of the "attack points" at once.
|
|
//
|
|
// Workflow with DFSan:
|
|
// * lib/Fuzzer/Fuzzer*.cpp is compiled w/o any instrumentation.
|
|
// * The code under test is compiled with DFSan *and* with instruction traces.
|
|
// * Every call to HOOK(a,b) is replaced by DFSan with
|
|
// __dfsw_HOOK(a, b, label(a), label(b)) so that __dfsw_HOOK
|
|
// gets all the taint labels for the arguments.
|
|
// * At the Fuzzer startup we assign a unique DFSan label
|
|
// to every byte of the input string (Fuzzer::CurrentUnitData) so that
|
|
// for any chunk of data we know which input bytes it has derived from.
|
|
// * The __dfsw_* functions (implemented in this file) record the
|
|
// parameters (i.e. the application data and the corresponding taint labels)
|
|
// in a global state.
|
|
//
|
|
// Parts of this code will not function when DFSan is not linked in.
|
|
// Instead of using ifdefs and thus requiring a separate build of lib/Fuzzer
|
|
// we redeclare the dfsan_* interface functions as weak and check if they
|
|
// are nullptr before calling.
|
|
// If this approach proves to be useful we may add attribute(weak) to the
|
|
// dfsan declarations in dfsan_interface.h
|
|
//
|
|
// This module is in the "proof of concept" stage.
|
|
// It is capable of solving only the simplest puzzles
|
|
// like test/dfsan/DFSanSimpleCmpTest.cpp.
|
|
//===----------------------------------------------------------------------===//
|
|
|
|
/* Example of manual usage (-fsanitize=dataflow is optional):
|
|
(
|
|
cd $LLVM/lib/Fuzzer/
|
|
clang -fPIC -c -g -O2 -std=c++11 Fuzzer*.cpp
|
|
clang++ -O0 -std=c++11 -fsanitize-coverage=edge,trace-cmp \
|
|
-fsanitize=dataflow \
|
|
test/SimpleCmpTest.cpp Fuzzer*.o
|
|
./a.out -use_traces=1
|
|
)
|
|
*/
|
|
|
|
#include "FuzzerDFSan.h"
|
|
#include "FuzzerInternal.h"
|
|
|
|
#include <algorithm>
|
|
#include <cstring>
|
|
#include <thread>
|
|
#include <map>
|
|
|
|
#if !LLVM_FUZZER_SUPPORTS_DFSAN
|
|
// Stubs for dfsan for platforms where dfsan does not exist and weak
|
|
// functions don't work.
|
|
extern "C" {
|
|
dfsan_label dfsan_create_label(const char *desc, void *userdata) { return 0; }
|
|
void dfsan_set_label(dfsan_label label, void *addr, size_t size) {}
|
|
void dfsan_add_label(dfsan_label label, void *addr, size_t size) {}
|
|
const struct dfsan_label_info *dfsan_get_label_info(dfsan_label label) {
|
|
return nullptr;
|
|
}
|
|
dfsan_label dfsan_read_label(const void *addr, size_t size) { return 0; }
|
|
} // extern "C"
|
|
#endif // !LLVM_FUZZER_SUPPORTS_DFSAN
|
|
|
|
namespace fuzzer {
|
|
|
|
// These values are copied from include/llvm/IR/InstrTypes.h.
|
|
// We do not include the LLVM headers here to remain independent.
|
|
// If these values ever change, an assertion in ComputeCmp will fail.
|
|
enum Predicate {
|
|
ICMP_EQ = 32, ///< equal
|
|
ICMP_NE = 33, ///< not equal
|
|
ICMP_UGT = 34, ///< unsigned greater than
|
|
ICMP_UGE = 35, ///< unsigned greater or equal
|
|
ICMP_ULT = 36, ///< unsigned less than
|
|
ICMP_ULE = 37, ///< unsigned less or equal
|
|
ICMP_SGT = 38, ///< signed greater than
|
|
ICMP_SGE = 39, ///< signed greater or equal
|
|
ICMP_SLT = 40, ///< signed less than
|
|
ICMP_SLE = 41, ///< signed less or equal
|
|
};
|
|
|
|
template <class U, class S>
|
|
bool ComputeCmp(size_t CmpType, U Arg1, U Arg2) {
|
|
switch(CmpType) {
|
|
case ICMP_EQ : return Arg1 == Arg2;
|
|
case ICMP_NE : return Arg1 != Arg2;
|
|
case ICMP_UGT: return Arg1 > Arg2;
|
|
case ICMP_UGE: return Arg1 >= Arg2;
|
|
case ICMP_ULT: return Arg1 < Arg2;
|
|
case ICMP_ULE: return Arg1 <= Arg2;
|
|
case ICMP_SGT: return (S)Arg1 > (S)Arg2;
|
|
case ICMP_SGE: return (S)Arg1 >= (S)Arg2;
|
|
case ICMP_SLT: return (S)Arg1 < (S)Arg2;
|
|
case ICMP_SLE: return (S)Arg1 <= (S)Arg2;
|
|
default: assert(0 && "unsupported CmpType");
|
|
}
|
|
return false;
|
|
}
|
|
|
|
static bool ComputeCmp(size_t CmpSize, size_t CmpType, uint64_t Arg1,
|
|
uint64_t Arg2) {
|
|
if (CmpSize == 8) return ComputeCmp<uint64_t, int64_t>(CmpType, Arg1, Arg2);
|
|
if (CmpSize == 4) return ComputeCmp<uint32_t, int32_t>(CmpType, Arg1, Arg2);
|
|
if (CmpSize == 2) return ComputeCmp<uint16_t, int16_t>(CmpType, Arg1, Arg2);
|
|
if (CmpSize == 1) return ComputeCmp<uint8_t, int8_t>(CmpType, Arg1, Arg2);
|
|
// Other size, ==
|
|
if (CmpType == ICMP_EQ) return Arg1 == Arg2;
|
|
// assert(0 && "unsupported cmp and type size combination");
|
|
return true;
|
|
}
|
|
|
|
// As a simplification we use the range of input bytes instead of a set of input
|
|
// bytes.
|
|
struct LabelRange {
|
|
uint16_t Beg, End; // Range is [Beg, End), thus Beg==End is an empty range.
|
|
|
|
LabelRange(uint16_t Beg = 0, uint16_t End = 0) : Beg(Beg), End(End) {}
|
|
|
|
static LabelRange Join(LabelRange LR1, LabelRange LR2) {
|
|
if (LR1.Beg == LR1.End) return LR2;
|
|
if (LR2.Beg == LR2.End) return LR1;
|
|
return {std::min(LR1.Beg, LR2.Beg), std::max(LR1.End, LR2.End)};
|
|
}
|
|
LabelRange &Join(LabelRange LR) {
|
|
return *this = Join(*this, LR);
|
|
}
|
|
static LabelRange Singleton(const dfsan_label_info *LI) {
|
|
uint16_t Idx = (uint16_t)(uintptr_t)LI->userdata;
|
|
assert(Idx > 0);
|
|
return {(uint16_t)(Idx - 1), Idx};
|
|
}
|
|
};
|
|
|
|
// For now, very simple: put Size bytes of Data at position Pos.
|
|
struct TraceBasedMutation {
|
|
uint32_t Pos;
|
|
Word W;
|
|
};
|
|
|
|
// Declared as static globals for faster checks inside the hooks.
|
|
static bool RecordingTraces = false;
|
|
static bool RecordingMemcmp = false;
|
|
|
|
class TraceState {
|
|
public:
|
|
TraceState(MutationDispatcher &MD, const FuzzingOptions &Options,
|
|
const Fuzzer *F)
|
|
: MD(MD), Options(Options), F(F) {}
|
|
|
|
LabelRange GetLabelRange(dfsan_label L);
|
|
void DFSanCmpCallback(uintptr_t PC, size_t CmpSize, size_t CmpType,
|
|
uint64_t Arg1, uint64_t Arg2, dfsan_label L1,
|
|
dfsan_label L2);
|
|
void DFSanMemcmpCallback(size_t CmpSize, const uint8_t *Data1,
|
|
const uint8_t *Data2, dfsan_label L1,
|
|
dfsan_label L2);
|
|
void DFSanSwitchCallback(uint64_t PC, size_t ValSizeInBits, uint64_t Val,
|
|
size_t NumCases, uint64_t *Cases, dfsan_label L);
|
|
void TraceCmpCallback(uintptr_t PC, size_t CmpSize, size_t CmpType,
|
|
uint64_t Arg1, uint64_t Arg2);
|
|
void TraceMemcmpCallback(size_t CmpSize, const uint8_t *Data1,
|
|
const uint8_t *Data2);
|
|
|
|
void TraceSwitchCallback(uintptr_t PC, size_t ValSizeInBits, uint64_t Val,
|
|
size_t NumCases, uint64_t *Cases);
|
|
int TryToAddDesiredData(uint64_t PresentData, uint64_t DesiredData,
|
|
size_t DataSize);
|
|
int TryToAddDesiredData(const uint8_t *PresentData,
|
|
const uint8_t *DesiredData, size_t DataSize);
|
|
|
|
void StartTraceRecording() {
|
|
if (!Options.UseTraces && !Options.UseMemcmp)
|
|
return;
|
|
RecordingTraces = Options.UseTraces;
|
|
RecordingMemcmp = Options.UseMemcmp;
|
|
NumMutations = 0;
|
|
MD.ClearAutoDictionary();
|
|
}
|
|
|
|
void StopTraceRecording() {
|
|
if (!RecordingTraces && !RecordingMemcmp)
|
|
return;
|
|
RecordingTraces = false;
|
|
RecordingMemcmp = false;
|
|
for (size_t i = 0; i < NumMutations; i++) {
|
|
auto &M = Mutations[i];
|
|
if (Options.Verbosity >= 2) {
|
|
AutoDictUnitCounts[M.W]++;
|
|
AutoDictAdds++;
|
|
if ((AutoDictAdds & (AutoDictAdds - 1)) == 0) {
|
|
typedef std::pair<size_t, Word> CU;
|
|
std::vector<CU> CountedUnits;
|
|
for (auto &I : AutoDictUnitCounts)
|
|
CountedUnits.push_back(std::make_pair(I.second, I.first));
|
|
std::sort(CountedUnits.begin(), CountedUnits.end(),
|
|
[](const CU &a, const CU &b) { return a.first > b.first; });
|
|
Printf("AutoDict:\n");
|
|
for (auto &I : CountedUnits) {
|
|
Printf(" %zd ", I.first);
|
|
PrintASCII(I.second);
|
|
Printf("\n");
|
|
}
|
|
}
|
|
}
|
|
MD.AddWordToAutoDictionary(M.W, M.Pos);
|
|
}
|
|
}
|
|
|
|
void AddMutation(uint32_t Pos, uint32_t Size, const uint8_t *Data) {
|
|
if (NumMutations >= kMaxMutations) return;
|
|
auto &M = Mutations[NumMutations++];
|
|
M.Pos = Pos;
|
|
M.W.Set(Data, Size);
|
|
}
|
|
|
|
void AddMutation(uint32_t Pos, uint32_t Size, uint64_t Data) {
|
|
assert(Size <= sizeof(Data));
|
|
AddMutation(Pos, Size, reinterpret_cast<uint8_t*>(&Data));
|
|
}
|
|
|
|
void EnsureDfsanLabels(size_t Size) {
|
|
for (; LastDfsanLabel < Size; LastDfsanLabel++) {
|
|
dfsan_label L = dfsan_create_label("input", (void *)(LastDfsanLabel + 1));
|
|
// We assume that no one else has called dfsan_create_label before.
|
|
if (L != LastDfsanLabel + 1) {
|
|
Printf("DFSan labels are not starting from 1, exiting\n");
|
|
exit(1);
|
|
}
|
|
}
|
|
}
|
|
|
|
private:
|
|
bool IsTwoByteData(uint64_t Data) {
|
|
int64_t Signed = static_cast<int64_t>(Data);
|
|
Signed >>= 16;
|
|
return Signed == 0 || Signed == -1L;
|
|
}
|
|
|
|
// We don't want to create too many trace-based mutations as it is both
|
|
// expensive and useless. So after some number of mutations is collected,
|
|
// start rejecting some of them. The more there are mutations the more we
|
|
// reject.
|
|
bool WantToHandleOneMoreMutation() {
|
|
const size_t FirstN = 64;
|
|
// Gladly handle first N mutations.
|
|
if (NumMutations <= FirstN) return true;
|
|
size_t Diff = NumMutations - FirstN;
|
|
size_t DiffLog = sizeof(long) * 8 - __builtin_clzl((long)Diff);
|
|
assert(DiffLog > 0 && DiffLog < 64);
|
|
bool WantThisOne = MD.GetRand()(1 << DiffLog) == 0; // 1 out of DiffLog.
|
|
return WantThisOne;
|
|
}
|
|
|
|
static const size_t kMaxMutations = 1 << 16;
|
|
size_t NumMutations;
|
|
TraceBasedMutation Mutations[kMaxMutations];
|
|
LabelRange LabelRanges[1 << (sizeof(dfsan_label) * 8)];
|
|
size_t LastDfsanLabel = 0;
|
|
MutationDispatcher &MD;
|
|
const FuzzingOptions Options;
|
|
const Fuzzer *F;
|
|
std::map<Word, size_t> AutoDictUnitCounts;
|
|
size_t AutoDictAdds = 0;
|
|
};
|
|
|
|
|
|
LabelRange TraceState::GetLabelRange(dfsan_label L) {
|
|
LabelRange &LR = LabelRanges[L];
|
|
if (LR.Beg < LR.End || L == 0)
|
|
return LR;
|
|
const dfsan_label_info *LI = dfsan_get_label_info(L);
|
|
if (LI->l1 || LI->l2)
|
|
return LR = LabelRange::Join(GetLabelRange(LI->l1), GetLabelRange(LI->l2));
|
|
return LR = LabelRange::Singleton(LI);
|
|
}
|
|
|
|
void TraceState::DFSanCmpCallback(uintptr_t PC, size_t CmpSize, size_t CmpType,
|
|
uint64_t Arg1, uint64_t Arg2, dfsan_label L1,
|
|
dfsan_label L2) {
|
|
assert(ReallyHaveDFSan());
|
|
if (!RecordingTraces || !F->InFuzzingThread()) return;
|
|
if (L1 == 0 && L2 == 0)
|
|
return; // Not actionable.
|
|
if (L1 != 0 && L2 != 0)
|
|
return; // Probably still actionable.
|
|
bool Res = ComputeCmp(CmpSize, CmpType, Arg1, Arg2);
|
|
uint64_t Data = L1 ? Arg2 : Arg1;
|
|
LabelRange LR = L1 ? GetLabelRange(L1) : GetLabelRange(L2);
|
|
|
|
for (size_t Pos = LR.Beg; Pos + CmpSize <= LR.End; Pos++) {
|
|
AddMutation(Pos, CmpSize, Data);
|
|
AddMutation(Pos, CmpSize, Data + 1);
|
|
AddMutation(Pos, CmpSize, Data - 1);
|
|
}
|
|
|
|
if (CmpSize > (size_t)(LR.End - LR.Beg))
|
|
AddMutation(LR.Beg, (unsigned)(LR.End - LR.Beg), Data);
|
|
|
|
|
|
if (Options.Verbosity >= 3)
|
|
Printf("DFSanCmpCallback: PC %lx S %zd T %zd A1 %llx A2 %llx R %d L1 %d L2 "
|
|
"%d MU %zd\n",
|
|
PC, CmpSize, CmpType, Arg1, Arg2, Res, L1, L2, NumMutations);
|
|
}
|
|
|
|
void TraceState::DFSanMemcmpCallback(size_t CmpSize, const uint8_t *Data1,
|
|
const uint8_t *Data2, dfsan_label L1,
|
|
dfsan_label L2) {
|
|
|
|
assert(ReallyHaveDFSan());
|
|
if (!RecordingMemcmp || !F->InFuzzingThread()) return;
|
|
if (L1 == 0 && L2 == 0)
|
|
return; // Not actionable.
|
|
if (L1 != 0 && L2 != 0)
|
|
return; // Probably still actionable.
|
|
|
|
const uint8_t *Data = L1 ? Data2 : Data1;
|
|
LabelRange LR = L1 ? GetLabelRange(L1) : GetLabelRange(L2);
|
|
for (size_t Pos = LR.Beg; Pos + CmpSize <= LR.End; Pos++) {
|
|
AddMutation(Pos, CmpSize, Data);
|
|
if (Options.Verbosity >= 3)
|
|
Printf("DFSanMemcmpCallback: Pos %d Size %d\n", Pos, CmpSize);
|
|
}
|
|
}
|
|
|
|
void TraceState::DFSanSwitchCallback(uint64_t PC, size_t ValSizeInBits,
|
|
uint64_t Val, size_t NumCases,
|
|
uint64_t *Cases, dfsan_label L) {
|
|
assert(ReallyHaveDFSan());
|
|
if (!RecordingTraces || !F->InFuzzingThread()) return;
|
|
if (!L) return; // Not actionable.
|
|
LabelRange LR = GetLabelRange(L);
|
|
size_t ValSize = ValSizeInBits / 8;
|
|
bool TryShort = IsTwoByteData(Val);
|
|
for (size_t i = 0; i < NumCases; i++)
|
|
TryShort &= IsTwoByteData(Cases[i]);
|
|
|
|
for (size_t Pos = LR.Beg; Pos + ValSize <= LR.End; Pos++)
|
|
for (size_t i = 0; i < NumCases; i++)
|
|
AddMutation(Pos, ValSize, Cases[i]);
|
|
|
|
if (TryShort)
|
|
for (size_t Pos = LR.Beg; Pos + 2 <= LR.End; Pos++)
|
|
for (size_t i = 0; i < NumCases; i++)
|
|
AddMutation(Pos, 2, Cases[i]);
|
|
|
|
if (Options.Verbosity >= 3)
|
|
Printf("DFSanSwitchCallback: PC %lx Val %zd SZ %zd # %zd L %d: {%d, %d} "
|
|
"TryShort %d\n",
|
|
PC, Val, ValSize, NumCases, L, LR.Beg, LR.End, TryShort);
|
|
}
|
|
|
|
int TraceState::TryToAddDesiredData(uint64_t PresentData, uint64_t DesiredData,
|
|
size_t DataSize) {
|
|
if (NumMutations >= kMaxMutations || !WantToHandleOneMoreMutation()) return 0;
|
|
const uint8_t *UnitData;
|
|
auto UnitSize = F->GetCurrentUnitInFuzzingThead(&UnitData);
|
|
int Res = 0;
|
|
const uint8_t *Beg = UnitData;
|
|
const uint8_t *End = Beg + UnitSize;
|
|
for (const uint8_t *Cur = Beg; Cur < End; Cur++) {
|
|
Cur = (uint8_t *)memmem(Cur, End - Cur, &PresentData, DataSize);
|
|
if (!Cur)
|
|
break;
|
|
size_t Pos = Cur - Beg;
|
|
assert(Pos < UnitSize);
|
|
AddMutation(Pos, DataSize, DesiredData);
|
|
AddMutation(Pos, DataSize, DesiredData + 1);
|
|
AddMutation(Pos, DataSize, DesiredData - 1);
|
|
Res++;
|
|
}
|
|
return Res;
|
|
}
|
|
|
|
int TraceState::TryToAddDesiredData(const uint8_t *PresentData,
|
|
const uint8_t *DesiredData,
|
|
size_t DataSize) {
|
|
if (NumMutations >= kMaxMutations || !WantToHandleOneMoreMutation()) return 0;
|
|
const uint8_t *UnitData;
|
|
auto UnitSize = F->GetCurrentUnitInFuzzingThead(&UnitData);
|
|
int Res = 0;
|
|
const uint8_t *Beg = UnitData;
|
|
const uint8_t *End = Beg + UnitSize;
|
|
for (const uint8_t *Cur = Beg; Cur < End; Cur++) {
|
|
Cur = (uint8_t *)memmem(Cur, End - Cur, PresentData, DataSize);
|
|
if (!Cur)
|
|
break;
|
|
size_t Pos = Cur - Beg;
|
|
assert(Pos < UnitSize);
|
|
AddMutation(Pos, DataSize, DesiredData);
|
|
Res++;
|
|
}
|
|
return Res;
|
|
}
|
|
|
|
void TraceState::TraceCmpCallback(uintptr_t PC, size_t CmpSize, size_t CmpType,
|
|
uint64_t Arg1, uint64_t Arg2) {
|
|
if (!RecordingTraces || !F->InFuzzingThread()) return;
|
|
if ((CmpType == ICMP_EQ || CmpType == ICMP_NE) && Arg1 == Arg2)
|
|
return; // No reason to mutate.
|
|
int Added = 0;
|
|
Added += TryToAddDesiredData(Arg1, Arg2, CmpSize);
|
|
Added += TryToAddDesiredData(Arg2, Arg1, CmpSize);
|
|
if (!Added && CmpSize == 4 && IsTwoByteData(Arg1) && IsTwoByteData(Arg2)) {
|
|
Added += TryToAddDesiredData(Arg1, Arg2, 2);
|
|
Added += TryToAddDesiredData(Arg2, Arg1, 2);
|
|
}
|
|
if (Options.Verbosity >= 3 && Added)
|
|
Printf("TraceCmp %zd/%zd: %p %zd %zd\n", CmpSize, CmpType, PC, Arg1, Arg2);
|
|
}
|
|
|
|
void TraceState::TraceMemcmpCallback(size_t CmpSize, const uint8_t *Data1,
|
|
const uint8_t *Data2) {
|
|
if (!RecordingMemcmp || !F->InFuzzingThread()) return;
|
|
CmpSize = std::min(CmpSize, Word::GetMaxSize());
|
|
int Added2 = TryToAddDesiredData(Data1, Data2, CmpSize);
|
|
int Added1 = TryToAddDesiredData(Data2, Data1, CmpSize);
|
|
if ((Added1 || Added2) && Options.Verbosity >= 3) {
|
|
Printf("MemCmp Added %d%d: ", Added1, Added2);
|
|
if (Added1) PrintASCII(Data1, CmpSize);
|
|
if (Added2) PrintASCII(Data2, CmpSize);
|
|
Printf("\n");
|
|
}
|
|
}
|
|
|
|
void TraceState::TraceSwitchCallback(uintptr_t PC, size_t ValSizeInBits,
|
|
uint64_t Val, size_t NumCases,
|
|
uint64_t *Cases) {
|
|
if (!RecordingTraces || !F->InFuzzingThread()) return;
|
|
size_t ValSize = ValSizeInBits / 8;
|
|
bool TryShort = IsTwoByteData(Val);
|
|
for (size_t i = 0; i < NumCases; i++)
|
|
TryShort &= IsTwoByteData(Cases[i]);
|
|
|
|
if (Options.Verbosity >= 3)
|
|
Printf("TraceSwitch: %p %zd # %zd; TryShort %d\n", PC, Val, NumCases,
|
|
TryShort);
|
|
|
|
for (size_t i = 0; i < NumCases; i++) {
|
|
TryToAddDesiredData(Val, Cases[i], ValSize);
|
|
if (TryShort)
|
|
TryToAddDesiredData(Val, Cases[i], 2);
|
|
}
|
|
}
|
|
|
|
static TraceState *TS;
|
|
|
|
void Fuzzer::StartTraceRecording() {
|
|
if (!TS) return;
|
|
TS->StartTraceRecording();
|
|
}
|
|
|
|
void Fuzzer::StopTraceRecording() {
|
|
if (!TS) return;
|
|
TS->StopTraceRecording();
|
|
}
|
|
|
|
void Fuzzer::AssignTaintLabels(uint8_t *Data, size_t Size) {
|
|
if (!Options.UseTraces && !Options.UseMemcmp) return;
|
|
if (!ReallyHaveDFSan()) return;
|
|
TS->EnsureDfsanLabels(Size);
|
|
for (size_t i = 0; i < Size; i++)
|
|
dfsan_set_label(i + 1, &Data[i], 1);
|
|
}
|
|
|
|
void Fuzzer::InitializeTraceState() {
|
|
if (!Options.UseTraces && !Options.UseMemcmp) return;
|
|
TS = new TraceState(MD, Options, this);
|
|
}
|
|
|
|
static size_t InternalStrnlen(const char *S, size_t MaxLen) {
|
|
size_t Len = 0;
|
|
for (; Len < MaxLen && S[Len]; Len++) {}
|
|
return Len;
|
|
}
|
|
|
|
} // namespace fuzzer
|
|
|
|
using fuzzer::TS;
|
|
using fuzzer::RecordingTraces;
|
|
using fuzzer::RecordingMemcmp;
|
|
|
|
extern "C" {
|
|
void __dfsw___sanitizer_cov_trace_cmp(uint64_t SizeAndType, uint64_t Arg1,
|
|
uint64_t Arg2, dfsan_label L0,
|
|
dfsan_label L1, dfsan_label L2) {
|
|
if (!RecordingTraces) return;
|
|
assert(L0 == 0);
|
|
uintptr_t PC = reinterpret_cast<uintptr_t>(__builtin_return_address(0));
|
|
uint64_t CmpSize = (SizeAndType >> 32) / 8;
|
|
uint64_t Type = (SizeAndType << 32) >> 32;
|
|
TS->DFSanCmpCallback(PC, CmpSize, Type, Arg1, Arg2, L1, L2);
|
|
}
|
|
|
|
void __dfsw___sanitizer_cov_trace_switch(uint64_t Val, uint64_t *Cases,
|
|
dfsan_label L1, dfsan_label L2) {
|
|
if (!RecordingTraces) return;
|
|
uintptr_t PC = reinterpret_cast<uintptr_t>(__builtin_return_address(0));
|
|
TS->DFSanSwitchCallback(PC, Cases[1], Val, Cases[0], Cases+2, L1);
|
|
}
|
|
|
|
void dfsan_weak_hook_memcmp(void *caller_pc, const void *s1, const void *s2,
|
|
size_t n, dfsan_label s1_label,
|
|
dfsan_label s2_label, dfsan_label n_label) {
|
|
if (!RecordingMemcmp) return;
|
|
dfsan_label L1 = dfsan_read_label(s1, n);
|
|
dfsan_label L2 = dfsan_read_label(s2, n);
|
|
TS->DFSanMemcmpCallback(n, reinterpret_cast<const uint8_t *>(s1),
|
|
reinterpret_cast<const uint8_t *>(s2), L1, L2);
|
|
}
|
|
|
|
void dfsan_weak_hook_strncmp(void *caller_pc, const char *s1, const char *s2,
|
|
size_t n, dfsan_label s1_label,
|
|
dfsan_label s2_label, dfsan_label n_label) {
|
|
if (!RecordingMemcmp) return;
|
|
n = std::min(n, fuzzer::InternalStrnlen(s1, n));
|
|
n = std::min(n, fuzzer::InternalStrnlen(s2, n));
|
|
dfsan_label L1 = dfsan_read_label(s1, n);
|
|
dfsan_label L2 = dfsan_read_label(s2, n);
|
|
TS->DFSanMemcmpCallback(n, reinterpret_cast<const uint8_t *>(s1),
|
|
reinterpret_cast<const uint8_t *>(s2), L1, L2);
|
|
}
|
|
|
|
void dfsan_weak_hook_strcmp(void *caller_pc, const char *s1, const char *s2,
|
|
dfsan_label s1_label, dfsan_label s2_label) {
|
|
if (!RecordingMemcmp) return;
|
|
size_t Len1 = strlen(s1);
|
|
size_t Len2 = strlen(s2);
|
|
size_t N = std::min(Len1, Len2);
|
|
if (N <= 1) return; // Not interesting.
|
|
dfsan_label L1 = dfsan_read_label(s1, Len1);
|
|
dfsan_label L2 = dfsan_read_label(s2, Len2);
|
|
TS->DFSanMemcmpCallback(N, reinterpret_cast<const uint8_t *>(s1),
|
|
reinterpret_cast<const uint8_t *>(s2), L1, L2);
|
|
}
|
|
|
|
// We may need to avoid defining weak hooks to stay compatible with older clang.
|
|
#ifndef LLVM_FUZZER_DEFINES_SANITIZER_WEAK_HOOOKS
|
|
# define LLVM_FUZZER_DEFINES_SANITIZER_WEAK_HOOOKS 1
|
|
#endif
|
|
|
|
#if LLVM_FUZZER_DEFINES_SANITIZER_WEAK_HOOOKS
|
|
void __sanitizer_weak_hook_memcmp(void *caller_pc, const void *s1,
|
|
const void *s2, size_t n, int result) {
|
|
if (!RecordingMemcmp) return;
|
|
if (result == 0) return; // No reason to mutate.
|
|
if (n <= 1) return; // Not interesting.
|
|
TS->TraceMemcmpCallback(n, reinterpret_cast<const uint8_t *>(s1),
|
|
reinterpret_cast<const uint8_t *>(s2));
|
|
}
|
|
|
|
void __sanitizer_weak_hook_strncmp(void *caller_pc, const char *s1,
|
|
const char *s2, size_t n, int result) {
|
|
if (!RecordingMemcmp) return;
|
|
if (result == 0) return; // No reason to mutate.
|
|
size_t Len1 = fuzzer::InternalStrnlen(s1, n);
|
|
size_t Len2 = fuzzer::InternalStrnlen(s2, n);
|
|
n = std::min(n, Len1);
|
|
n = std::min(n, Len2);
|
|
if (n <= 1) return; // Not interesting.
|
|
TS->TraceMemcmpCallback(n, reinterpret_cast<const uint8_t *>(s1),
|
|
reinterpret_cast<const uint8_t *>(s2));
|
|
}
|
|
|
|
void __sanitizer_weak_hook_strcmp(void *caller_pc, const char *s1,
|
|
const char *s2, int result) {
|
|
if (!RecordingMemcmp) return;
|
|
if (result == 0) return; // No reason to mutate.
|
|
size_t Len1 = strlen(s1);
|
|
size_t Len2 = strlen(s2);
|
|
size_t N = std::min(Len1, Len2);
|
|
if (N <= 1) return; // Not interesting.
|
|
TS->TraceMemcmpCallback(N, reinterpret_cast<const uint8_t *>(s1),
|
|
reinterpret_cast<const uint8_t *>(s2));
|
|
}
|
|
|
|
#endif // LLVM_FUZZER_DEFINES_SANITIZER_WEAK_HOOOKS
|
|
|
|
__attribute__((visibility("default")))
|
|
void __sanitizer_cov_trace_cmp(uint64_t SizeAndType, uint64_t Arg1,
|
|
uint64_t Arg2) {
|
|
if (!RecordingTraces) return;
|
|
uintptr_t PC = reinterpret_cast<uintptr_t>(__builtin_return_address(0));
|
|
uint64_t CmpSize = (SizeAndType >> 32) / 8;
|
|
uint64_t Type = (SizeAndType << 32) >> 32;
|
|
TS->TraceCmpCallback(PC, CmpSize, Type, Arg1, Arg2);
|
|
}
|
|
|
|
__attribute__((visibility("default")))
|
|
void __sanitizer_cov_trace_switch(uint64_t Val, uint64_t *Cases) {
|
|
if (!RecordingTraces) return;
|
|
uintptr_t PC = reinterpret_cast<uintptr_t>(__builtin_return_address(0));
|
|
TS->TraceSwitchCallback(PC, Cases[1], Val, Cases[0], Cases + 2);
|
|
}
|
|
|
|
} // extern "C"
|