fix sequence validation and bounds check in ZSTD_copySequencesToSeqStore()

This commit is contained in:
Danielle Rozenblit
2023-01-20 10:32:35 -08:00
parent bce0382c82
commit aa385ece13
2 changed files with 94 additions and 8 deletions
+10 -8
View File
@@ -6156,8 +6156,8 @@ size_t ZSTD_compress2(ZSTD_CCtx* cctx,
* @returns a ZSTD error code if sequence is not valid
*/
static size_t
ZSTD_validateSequence(U32 offCode, U32 matchLength,
size_t posInSrc, U32 windowLog, size_t dictSize)
ZSTD_validateSequence(U32 offCode, U32 matchLength, U32 minMatch,
size_t posInSrc, U32 windowLog, size_t dictSize, int useExternalMatchFinder)
{
U32 const windowSize = 1u << windowLog;
/* posInSrc represents the amount of data the decoder would decode up to this point.
@@ -6168,6 +6168,8 @@ ZSTD_validateSequence(U32 offCode, U32 matchLength,
size_t const offsetBound = posInSrc > windowSize ? (size_t)windowSize : posInSrc + (size_t)dictSize;
RETURN_ERROR_IF(offCode > OFFSET_TO_OFFBASE(offsetBound), corruption_detected, "Offset too large!");
RETURN_ERROR_IF(matchLength < MINMATCH, corruption_detected, "Matchlength too small");
/* Validate maxNbSeq is large enough for the given matchLength and minMatch */
RETURN_ERROR_IF(!useExternalMatchFinder && minMatch >= 4 && matchLength < 4, corruption_detected, "Matchlength too small for the minMatch");
return 0;
}
@@ -6220,11 +6222,11 @@ ZSTD_copySequencesToSeqStoreExplicitBlockDelim(ZSTD_CCtx* cctx,
DEBUGLOG(6, "Storing sequence: (of: %u, ml: %u, ll: %u)", offBase, matchLength, litLength);
if (cctx->appliedParams.validateSequences) {
seqPos->posInSrc += litLength + matchLength;
FORWARD_IF_ERROR(ZSTD_validateSequence(offBase, matchLength, seqPos->posInSrc,
cctx->appliedParams.cParams.windowLog, dictSize),
FORWARD_IF_ERROR(ZSTD_validateSequence(offBase, matchLength, cctx->appliedParams.cParams.minMatch, seqPos->posInSrc,
cctx->appliedParams.cParams.windowLog, dictSize, cctx->appliedParams.useExternalMatchFinder),
"Sequence validation failed");
}
RETURN_ERROR_IF(idx - seqPos->idx > cctx->seqStore.maxNbSeq, memory_allocation,
RETURN_ERROR_IF(idx - seqPos->idx >= cctx->seqStore.maxNbSeq, memory_allocation,
"Not enough memory allocated. Try adjusting ZSTD_c_minMatch.");
ZSTD_storeSeq(&cctx->seqStore, litLength, ip, iend, offBase, matchLength);
ip += matchLength + litLength;
@@ -6332,12 +6334,12 @@ ZSTD_copySequencesToSeqStoreNoBlockDelim(ZSTD_CCtx* cctx, ZSTD_sequencePosition*
if (cctx->appliedParams.validateSequences) {
seqPos->posInSrc += litLength + matchLength;
FORWARD_IF_ERROR(ZSTD_validateSequence(offBase, matchLength, seqPos->posInSrc,
cctx->appliedParams.cParams.windowLog, dictSize),
FORWARD_IF_ERROR(ZSTD_validateSequence(offBase, matchLength, cctx->appliedParams.cParams.minMatch, seqPos->posInSrc,
cctx->appliedParams.cParams.windowLog, dictSize, cctx->appliedParams.useExternalMatchFinder),
"Sequence validation failed");
}
DEBUGLOG(6, "Storing sequence: (of: %u, ml: %u, ll: %u)", offBase, matchLength, litLength);
RETURN_ERROR_IF(idx - seqPos->idx > cctx->seqStore.maxNbSeq, memory_allocation,
RETURN_ERROR_IF(idx - seqPos->idx >= cctx->seqStore.maxNbSeq, memory_allocation,
"Not enough memory allocated. Try adjusting ZSTD_c_minMatch.");
ZSTD_storeSeq(&cctx->seqStore, litLength, ip, iend, offBase, matchLength);
ip += matchLength + litLength;