Fix uninitialized memory read

This commit is contained in:
Nick Terrell
2016-11-14 13:57:05 -08:00
parent cdff19c4b3
commit 24701de877
7 changed files with 46 additions and 67 deletions
+7 -10
View File
@@ -3021,7 +3021,6 @@ struct ZSTDv07_DCtx_s
U32 dictID;
const BYTE* litPtr;
ZSTDv07_customMem customMem;
size_t litBufSize;
size_t litSize;
BYTE litBuffer[ZSTDv07_BLOCKSIZE_ABSOLUTEMAX + WILDCOPY_OVERLENGTH];
BYTE headerBuffer[ZSTDv07_FRAMEHEADERSIZE_MAX];
@@ -3395,9 +3394,9 @@ size_t ZSTDv07_decodeLiteralsBlock(ZSTDv07_DCtx* dctx,
return ERROR(corruption_detected);
dctx->litPtr = dctx->litBuffer;
dctx->litBufSize = ZSTDv07_BLOCKSIZE_ABSOLUTEMAX+8;
dctx->litSize = litSize;
dctx->litEntropy = 1;
memset(dctx->litBuffer + dctx->litSize, 0, WILDCOPY_OVERLENGTH);
return litCSize + lhSize;
}
case lbt_repeat:
@@ -3418,8 +3417,8 @@ size_t ZSTDv07_decodeLiteralsBlock(ZSTDv07_DCtx* dctx,
if (HUFv07_isError(errorCode)) return ERROR(corruption_detected);
}
dctx->litPtr = dctx->litBuffer;
dctx->litBufSize = ZSTDv07_BLOCKSIZE_ABSOLUTEMAX+WILDCOPY_OVERLENGTH;
dctx->litSize = litSize;
memset(dctx->litBuffer + dctx->litSize, 0, WILDCOPY_OVERLENGTH);
return litCSize + lhSize;
}
case lbt_raw:
@@ -3443,13 +3442,12 @@ size_t ZSTDv07_decodeLiteralsBlock(ZSTDv07_DCtx* dctx,
if (litSize+lhSize > srcSize) return ERROR(corruption_detected);
memcpy(dctx->litBuffer, istart+lhSize, litSize);
dctx->litPtr = dctx->litBuffer;
dctx->litBufSize = ZSTDv07_BLOCKSIZE_ABSOLUTEMAX+8;
dctx->litSize = litSize;
memset(dctx->litBuffer + dctx->litSize, 0, WILDCOPY_OVERLENGTH);
return lhSize+litSize;
}
/* direct reference into compressed stream */
dctx->litPtr = istart+lhSize;
dctx->litBufSize = srcSize-lhSize;
dctx->litSize = litSize;
return lhSize+litSize;
}
@@ -3473,8 +3471,8 @@ size_t ZSTDv07_decodeLiteralsBlock(ZSTDv07_DCtx* dctx,
if (litSize > ZSTDv07_BLOCKSIZE_ABSOLUTEMAX) return ERROR(corruption_detected);
memset(dctx->litBuffer, istart[lhSize], litSize);
dctx->litPtr = dctx->litBuffer;
dctx->litBufSize = ZSTDv07_BLOCKSIZE_ABSOLUTEMAX+WILDCOPY_OVERLENGTH;
dctx->litSize = litSize;
memset(dctx->litBuffer + dctx->litSize, 0, WILDCOPY_OVERLENGTH);
return lhSize+1;
}
default:
@@ -3662,7 +3660,7 @@ static seq_t ZSTDv07_decodeSequence(seqState_t* seqState)
static
size_t ZSTDv07_execSequence(BYTE* op,
BYTE* const oend, seq_t sequence,
const BYTE** litPtr, const BYTE* const litLimit_w,
const BYTE** litPtr, const BYTE* const litLimit,
const BYTE* const base, const BYTE* const vBase, const BYTE* const dictEnd)
{
BYTE* const oLitEnd = op + sequence.litLength;
@@ -3674,7 +3672,7 @@ size_t ZSTDv07_execSequence(BYTE* op,
/* check */
if ((oLitEnd>oend_w) | (oMatchEnd>oend)) return ERROR(dstSize_tooSmall); /* last match must start at a minimum distance of WILDCOPY_OVERLENGTH from oend */
if (iLitEnd > litLimit_w) return ERROR(corruption_detected); /* over-read beyond lit buffer */
if (iLitEnd > litLimit) return ERROR(corruption_detected); /* over-read beyond lit buffer */
/* copy Literals */
ZSTDv07_wildcopy(op, *litPtr, sequence.litLength); /* note : since oLitEnd <= oend-WILDCOPY_OVERLENGTH, no risk of overwrite beyond oend */
@@ -3746,7 +3744,6 @@ static size_t ZSTDv07_decompressSequences(
BYTE* const oend = ostart + maxDstSize;
BYTE* op = ostart;
const BYTE* litPtr = dctx->litPtr;
const BYTE* const litLimit_w = litPtr + dctx->litBufSize - WILDCOPY_OVERLENGTH;
const BYTE* const litEnd = litPtr + dctx->litSize;
FSEv07_DTable* DTableLL = dctx->LLTable;
FSEv07_DTable* DTableML = dctx->MLTable;
@@ -3776,7 +3773,7 @@ static size_t ZSTDv07_decompressSequences(
for ( ; (BITv07_reloadDStream(&(seqState.DStream)) <= BITv07_DStream_completed) && nbSeq ; ) {
nbSeq--;
{ seq_t const sequence = ZSTDv07_decodeSequence(&seqState);
size_t const oneSeqSize = ZSTDv07_execSequence(op, oend, sequence, &litPtr, litLimit_w, base, vBase, dictEnd);
size_t const oneSeqSize = ZSTDv07_execSequence(op, oend, sequence, &litPtr, litEnd, base, vBase, dictEnd);
if (ZSTDv07_isError(oneSeqSize)) return oneSeqSize;
op += oneSeqSize;
} }