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Merge pull request #550 from iburinoc/matchoverlenwrite

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execSequence copies up to 2*WILDCOPY_OVERLENGTH extra
This commit is contained in:
Yann Collet 2017-02-16 18:14:47 -08:00 committed by GitHub
commit f2da1b1f22
4 changed files with 16 additions and 8 deletions
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2
lib/decompress/zstd_decompress.c
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@ -2260,7 +2260,7 @@ size_t ZSTD_decompressStream(ZSTD_DStream* zds, ZSTD_outBuffer* output, ZSTD_inB
/* Adapt buffer sizes to frame header instructions */
{ size_t const blockSize = MIN(zds->fParams.windowSize, ZSTD_BLOCKSIZE_ABSOLUTEMAX);
size_t const neededOutSize = zds->fParams.windowSize + blockSize + WILDCOPY_OVERLENGTH;
size_t const neededOutSize = zds->fParams.windowSize + blockSize + WILDCOPY_OVERLENGTH * 2;
zds->blockSize = blockSize;
if (zds->inBuffSize < blockSize) {
ZSTD_free(zds->inBuff, zds->customMem);

2
lib/legacy/zstd_v06.c
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@ -4108,7 +4108,7 @@ size_t ZBUFFv06_decompressContinue(ZBUFFv06_DCtx* zbd,
zbd->inBuff = (char*)malloc(blockSize);
if (zbd->inBuff == NULL) return ERROR(memory_allocation);
}
{ size_t const neededOutSize = ((size_t)1 << zbd->fParams.windowLog) + blockSize + WILDCOPY_OVERLENGTH;
{ size_t const neededOutSize = ((size_t)1 << zbd->fParams.windowLog) + blockSize + WILDCOPY_OVERLENGTH * 2;
if (zbd->outBuffSize < neededOutSize) {
free(zbd->outBuff);
zbd->outBuffSize = neededOutSize;

2
lib/legacy/zstd_v07.c
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@ -4483,7 +4483,7 @@ size_t ZBUFFv07_decompressContinue(ZBUFFv07_DCtx* zbd,
zbd->inBuff = (char*)zbd->customMem.customAlloc(zbd->customMem.opaque, blockSize);
if (zbd->inBuff == NULL) return ERROR(memory_allocation);
}
{ size_t const neededOutSize = zbd->fParams.windowSize + blockSize + WILDCOPY_OVERLENGTH;
{ size_t const neededOutSize = zbd->fParams.windowSize + blockSize + WILDCOPY_OVERLENGTH * 2;
if (zbd->outBuffSize < neededOutSize) {
zbd->customMem.customFree(zbd->customMem.opaque, zbd->outBuff);
zbd->outBuffSize = neededOutSize;

18
tests/zstreamtest.c
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@ -469,15 +469,23 @@ static int basicUnitTests(U32 seed, double compressibility, ZSTD_customMem custo
/* Overlen overwriting window data bug */
DISPLAYLEVEL(3, "test%3i : wildcopy doesn't overwrite potential match data : ", testNb++);
{ const char* testCase =
"\x28\xB5\x2F\xFD\x04\x00\x4C\x00\x00\x10\x61\x61\x01\x00\xFC\x2A"
"\xC0\x02\x44\x00\x00\x08\x62\x01\x00\xFC\x2A\x10\x02\x00\x00\x00"
"\x4D\x00\x00\x00\x02\x40\x00\x01\x64\xE0\xE6\x19\xC1\xFB\x54\x9E";
{ /* This test has a window size of 1024 bytes and consists of 3 blocks:
1. 'a' repeated 517 times
2. 'b' repeated 516 times
3. a compressed block with no literals and 3 sequence commands:
litlength = 0, offset = 24, match length = 24
litlength = 0, offset = 24, match length = 3 (this one creates an overlength write of length 2*WILDCOPY_OVERLENGTH - 3)
litlength = 0, offset = 1021, match length = 3 (this one will try to read from overwritten data if the buffer is too small) */
const char* testCase =
"\x28\xB5\x2F\xFD\x04\x00\x4C\x00\x00\x10\x61\x61\x01\x00\x00\x2A"
"\x80\x05\x44\x00\x00\x08\x62\x01\x00\x00\x2A\x20\x04\x5D\x00\x00"
"\x00\x03\x40\x00\x00\x64\x60\x27\xB0\xE0\x0C\x67\x62\xCE\xE0";
ZSTD_DStream* zds = ZSTD_createDStream();
ZSTD_initDStream(zds);
inBuff.src = testCase;
inBuff.size = 48;
inBuff.size = 47;
inBuff.pos = 0;
outBuff.dst = decodedBuffer;
outBuff.size = CNBufferSize;