[fix] Always return dstSize_tooSmall when it is the case

This commit is contained in:
Nick Terrell 2020-08-15 12:32:57 -07:00
parent e33e5eece3
commit 1302f8d676
7 changed files with 91 additions and 12 deletions

View File

@ -579,11 +579,11 @@ static size_t ZSTD_copyRawBlock(void* dst, size_t dstCapacity,
const void* src, size_t srcSize)
{
DEBUGLOG(5, "ZSTD_copyRawBlock");
RETURN_ERROR_IF(srcSize > dstCapacity, dstSize_tooSmall, "");
if (dst == NULL) {
if (srcSize == 0) return 0;
RETURN_ERROR(dstBuffer_null, "");
}
RETURN_ERROR_IF(srcSize > dstCapacity, dstSize_tooSmall, "");
memcpy(dst, src, srcSize);
return srcSize;
}
@ -592,11 +592,11 @@ static size_t ZSTD_setRleBlock(void* dst, size_t dstCapacity,
BYTE b,
size_t regenSize)
{
RETURN_ERROR_IF(regenSize > dstCapacity, dstSize_tooSmall, "");
if (dst == NULL) {
if (regenSize == 0) return 0;
RETURN_ERROR(dstBuffer_null, "");
}
RETURN_ERROR_IF(regenSize > dstCapacity, dstSize_tooSmall, "");
memset(dst, b, regenSize);
return regenSize;
}

View File

@ -1084,14 +1084,14 @@ ZSTD_decompressSequences_body( ZSTD_DCtx* dctx,
#endif
DEBUGLOG(6, "regenerated sequence size : %u", (U32)oneSeqSize);
BIT_reloadDStream(&(seqState.DStream));
op += oneSeqSize;
/* gcc and clang both don't like early returns in this loop.
* gcc doesn't like early breaks either.
* Instead save an error and report it at the end.
* When there is an error, don't increment op, so we don't
* overwrite.
* Instead break and check for an error at the end of the loop.
*/
if (UNLIKELY(ZSTD_isError(oneSeqSize))) error = oneSeqSize;
else op += oneSeqSize;
if (UNLIKELY(ZSTD_isError(oneSeqSize))) {
error = oneSeqSize;
break;
}
if (UNLIKELY(!--nbSeq)) break;
}

View File

@ -95,7 +95,8 @@ FUZZ_TARGETS := \
simple_compress \
dictionary_loader \
raw_dictionary_round_trip \
dictionary_stream_round_trip
dictionary_stream_round_trip \
decompress_dstSize_tooSmall
all: $(FUZZ_TARGETS)
@ -180,6 +181,9 @@ zstd_frame_info: $(FUZZ_HEADERS) $(FUZZ_DECOMPRESS_OBJ) d_fuzz_zstd_frame_info.o
dictionary_loader: $(FUZZ_HEADERS) $(FUZZ_ROUND_TRIP_OBJ) rt_fuzz_dictionary_loader.o
$(CXX) $(FUZZ_TARGET_FLAGS) $(FUZZ_ROUND_TRIP_OBJ) rt_fuzz_dictionary_loader.o $(LIB_FUZZING_ENGINE) -o $@
decompress_dstSize_tooSmall: $(FUZZ_HEADERS) $(FUZZ_DECOMPRESS_OBJ) d_fuzz_decompress_dstSize_tooSmall.o
$(CXX) $(FUZZ_TARGET_FLAGS) $(FUZZ_DECOMPRESS_OBJ) d_fuzz_decompress_dstSize_tooSmall.o $(LIB_FUZZING_ENGINE) -o $@
libregression.a: $(FUZZ_HEADERS) $(PRGDIR)/util.h $(PRGDIR)/util.c d_fuzz_regression_driver.o
$(AR) $(FUZZ_ARFLAGS) $@ d_fuzz_regression_driver.o

View File

@ -0,0 +1,70 @@
/*
* Copyright (c) 2016-2020, Facebook, Inc.
* All rights reserved.
*
* This source code is licensed under both the BSD-style license (found in the
* LICENSE file in the root directory of this source tree) and the GPLv2 (found
* in the COPYING file in the root directory of this source tree).
* You may select, at your option, one of the above-listed licenses.
*/
/**
* This fuzz target attempts to decompress a valid compressed frame into
* an output buffer that is too small to ensure we always get
* ZSTD_error_dstSize_tooSmall.
*/
#include <stddef.h>
#include <stdlib.h>
#include <stdio.h>
#include "fuzz_helpers.h"
#include "zstd.h"
#include "zstd_errors.h"
#include "zstd_helpers.h"
#include "fuzz_data_producer.h"
static ZSTD_CCtx *cctx = NULL;
static ZSTD_DCtx *dctx = NULL;
int LLVMFuzzerTestOneInput(const uint8_t *src, size_t size)
{
/* Give a random portion of src data to the producer, to use for
parameter generation. The rest will be used for (de)compression */
FUZZ_dataProducer_t *producer = FUZZ_dataProducer_create(src, size);
size_t rBufSize = FUZZ_dataProducer_uint32Range(producer, 0, size);
size = FUZZ_dataProducer_remainingBytes(producer);
/* Ensure the round-trip buffer is too small. */
if (rBufSize >= size) {
rBufSize = size > 0 ? size - 1 : 0;
}
size_t const cBufSize = ZSTD_compressBound(size);
if (!cctx) {
cctx = ZSTD_createCCtx();
FUZZ_ASSERT(cctx);
}
if (!dctx) {
dctx = ZSTD_createDCtx();
FUZZ_ASSERT(dctx);
}
void *cBuf = FUZZ_malloc(cBufSize);
void *rBuf = FUZZ_malloc(rBufSize);
size_t const cSize = ZSTD_compressCCtx(cctx, cBuf, cBufSize, src, size, 1);
FUZZ_ZASSERT(cSize);
size_t const rSize = ZSTD_decompressDCtx(dctx, rBuf, rBufSize, cBuf, cSize);
if (size == 0) {
FUZZ_ASSERT(rSize == 0);
} else {
FUZZ_ASSERT(ZSTD_isError(rSize));
FUZZ_ASSERT(ZSTD_getErrorCode(rSize) == ZSTD_error_dstSize_tooSmall);
}
free(cBuf);
free(rBuf);
FUZZ_dataProducer_free(producer);
#ifndef STATEFUL_FUZZING
ZSTD_freeCCtx(cctx); cctx = NULL;
ZSTD_freeDCtx(dctx); dctx = NULL;
#endif
return 0;
}

View File

@ -59,6 +59,7 @@ TARGET_INFO = {
'dictionary_loader': TargetInfo(InputType.DICTIONARY_DATA),
'raw_dictionary_round_trip': TargetInfo(InputType.RAW_DATA),
'dictionary_stream_round_trip': TargetInfo(InputType.RAW_DATA),
'decompress_dstSize_tooSmall': TargetInfo(InputType.RAW_DATA),
}
TARGETS = list(TARGET_INFO.keys())
ALL_TARGETS = TARGETS + ['all']

View File

@ -19,6 +19,7 @@
#include <stdio.h>
#include "fuzz_helpers.h"
#include "zstd.h"
#include "zstd_errors.h"
#include "zstd_helpers.h"
#include "fuzz_data_producer.h"
@ -42,7 +43,10 @@ int LLVMFuzzerTestOneInput(const uint8_t *src, size_t size)
}
void *rBuf = FUZZ_malloc(bufSize);
ZSTD_compressCCtx(cctx, rBuf, bufSize, src, size, cLevel);
size_t const ret = ZSTD_compressCCtx(cctx, rBuf, bufSize, src, size, cLevel);
if (ZSTD_isError(ret)) {
FUZZ_ASSERT(ZSTD_getErrorCode(ret) == ZSTD_error_dstSize_tooSmall);
}
free(rBuf);
FUZZ_dataProducer_free(producer);
#ifndef STATEFUL_FUZZING

View File

@ -3053,7 +3053,7 @@ static int fuzzerTests(U32 seed, unsigned nbTests, unsigned startTest, U32 const
DISPLAYLEVEL(5, "fuzzer t%u: compress into too small buffer of size %u (missing %u bytes) \n",
testNb, (unsigned)tooSmallSize, (unsigned)missing);
{ size_t const errorCode = ZSTD_compressCCtx(ctx, dstBuffer, tooSmallSize, sampleBuffer, sampleSize, cLevel);
CHECK(!ZSTD_isError(errorCode), "ZSTD_compressCCtx should have failed ! (buffer too small : %u < %u)", (unsigned)tooSmallSize, (unsigned)cSize); }
CHECK(ZSTD_getErrorCode(errorCode) != ZSTD_error_dstSize_tooSmall, "ZSTD_compressCCtx should have failed ! (buffer too small : %u < %u)", (unsigned)tooSmallSize, (unsigned)cSize); }
{ unsigned endCheck; memcpy(&endCheck, dstBuffer+tooSmallSize, sizeof(endCheck));
CHECK(endCheck != endMark, "ZSTD_compressCCtx : dst buffer overflow (check.%08X != %08X.mark)", endCheck, endMark); }
} }
@ -3100,7 +3100,7 @@ static int fuzzerTests(U32 seed, unsigned nbTests, unsigned startTest, U32 const
static const BYTE token = 0xA9;
dstBuffer[tooSmallSize] = token;
{ size_t const errorCode = ZSTD_decompress(dstBuffer, tooSmallSize, cBuffer, cSize);
CHECK(!ZSTD_isError(errorCode), "ZSTD_decompress should have failed : %u > %u (dst buffer too small)", (unsigned)errorCode, (unsigned)tooSmallSize); }
CHECK(ZSTD_getErrorCode(errorCode) != ZSTD_error_dstSize_tooSmall, "ZSTD_decompress should have failed : %u > %u (dst buffer too small)", (unsigned)errorCode, (unsigned)tooSmallSize); }
CHECK(dstBuffer[tooSmallSize] != token, "ZSTD_decompress : dst buffer overflow");
}