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dictBuilder: validate buffer capacities in ZDICT_addEntropyTablesFromBuffer_advanced #4869

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dictBuilder: validate buffer capacities in ZDICT_addEntropyTablesFromBuffer_advanced #4869

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4 changes: 4 additions & 0 deletions lib/dictBuilder/zdict.c
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Original file line number Diff line number Diff line change
Expand Up @@ -950,6 +950,10 @@ static size_t ZDICT_addEntropyTablesFromBuffer_advanced(
U32 const notificationLevel = params.notificationLevel;
size_t hSize = 8;

/* check conditions */
if ((dictBuffer == NULL) || (dictBufferCapacity < dictContentSize) || (dictBufferCapacity < hSize))
return ERROR(dstSize_tooSmall);

/* calculate entropy tables */
DISPLAYLEVEL(2, "\r%70s\r", ""); /* clean display line */
DISPLAYLEVEL(2, "statistics ... \n");
Expand Down
67 changes: 67 additions & 0 deletions tests/fuzzer.c
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Original file line number Diff line number Diff line change
Expand Up @@ -34,6 +34,7 @@
#define ZSTD_DISABLE_DEPRECATE_WARNINGS /* No deprecation warnings, we still test some deprecated functions */
#include "zstd.h" /* ZSTD_VERSION_STRING */
#include "zstd_errors.h" /* ZSTD_getErrorCode */
#define ZDICT_DISABLE_DEPRECATE_WARNINGS /* No deprecation warnings, we still test deprecated functions */
#define ZDICT_STATIC_LINKING_ONLY
#include "zdict.h" /* ZDICT_trainFromBuffer */
#include "mem.h"
Expand Down Expand Up @@ -3136,6 +3137,72 @@ static int basicUnitTests(U32 const seed, double compressibility)
}
DISPLAYLEVEL(3, "OK : %u \n", (unsigned)dictHeaderSize);

DISPLAYLEVEL(3, "test%3i : ZDICT_addEntropyTablesFromBuffer capacity bounds : ", testNb++);
{ size_t const validCapacity = 1024;
size_t const validContentSize = 128;
BYTE* const smallBuf = (BYTE*)malloc(7);
BYTE* const contentOverflowBuf = (BYTE*)malloc(16);
BYTE* const validBuf = (BYTE*)malloc(validCapacity);
size_t res;
if (smallBuf == NULL || contentOverflowBuf == NULL || validBuf == NULL) {
free(smallBuf);
free(contentOverflowBuf);
free(validBuf);
goto _output_error;
}
memset(smallBuf, 0, 7);
memset(contentOverflowBuf, 0, 16);
{ U32 u; for (u=0; u<nbSamples; u++) samplesSizes[u] = sampleUnitSize; }

/* negative checks: reject out-of-bounds capacities and null destination */
res = ZDICT_addEntropyTablesFromBuffer(smallBuf, 0, 7, CNBuffer, samplesSizes, nbSamples);
if (!ZDICT_isError(res) || ZSTD_getErrorCode(res) != ZSTD_error_dstSize_tooSmall) {
free(smallBuf);
free(contentOverflowBuf);
free(validBuf);
goto _output_error;
}
res = ZDICT_addEntropyTablesFromBuffer(smallBuf, 0, 0, CNBuffer, samplesSizes, nbSamples);
if (!ZDICT_isError(res) || ZSTD_getErrorCode(res) != ZSTD_error_dstSize_tooSmall) {
free(smallBuf);
free(contentOverflowBuf);
free(validBuf);
goto _output_error;
}
res = ZDICT_addEntropyTablesFromBuffer(contentOverflowBuf, 17, 16, CNBuffer, samplesSizes, nbSamples);
if (!ZDICT_isError(res) || ZSTD_getErrorCode(res) != ZSTD_error_dstSize_tooSmall) {
free(smallBuf);
free(contentOverflowBuf);
free(validBuf);
goto _output_error;
}
res = ZDICT_addEntropyTablesFromBuffer(NULL, 0, 0, CNBuffer, samplesSizes, nbSamples);
if (!ZDICT_isError(res) || ZSTD_getErrorCode(res) != ZSTD_error_dstSize_tooSmall) {
free(smallBuf);
free(contentOverflowBuf);
free(validBuf);
goto _output_error;
}

/* positive control: valid capacity and trailing dictionary content */
memset(validBuf, 0, validCapacity);
memcpy(validBuf + validCapacity - validContentSize, CNBuffer, validContentSize);
res = ZDICT_addEntropyTablesFromBuffer(validBuf, validContentSize, validCapacity,
CNBuffer, samplesSizes, nbSamples);
if (ZDICT_isError(res) || res > validCapacity || ZDICT_getDictID(validBuf, res) == 0) {
free(smallBuf);
free(contentOverflowBuf);
free(validBuf);
goto _output_error;
}
assert(ZDICT_getDictID(validBuf, res) != 0);

free(smallBuf);
free(contentOverflowBuf);
free(validBuf);
}
DISPLAYLEVEL(3, "OK \n");

DISPLAYLEVEL(3, "test%3i : compress with dictionary : ", testNb++);
cSize = ZSTD_compress_usingDict(cctx, compressedBuffer, compressedBufferSize,
CNBuffer, CNBuffSize,
Expand Down