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
@@ -2893,7 +2893,6 @@ struct ZSTDv06_DCtx_s
ZSTDv06_dStage stage;
U32 flagRepeatTable;
const BYTE* litPtr;
size_t litBufSize;
size_t litSize;
BYTE litBuffer[ZSTDv06_BLOCKSIZE_MAX + WILDCOPY_OVERLENGTH];
BYTE headerBuffer[ZSTDv06_FRAMEHEADERSIZE_MAX];
@@ -3170,8 +3169,8 @@ size_t ZSTDv06_decodeLiteralsBlock(ZSTDv06_DCtx* dctx,
return ERROR(corruption_detected);
dctx->litPtr = dctx->litBuffer;
dctx->litBufSize = ZSTDv06_BLOCKSIZE_MAX+8;
dctx->litSize = litSize;
memset(dctx->litBuffer + dctx->litSize, 0, WILDCOPY_OVERLENGTH);
return litCSize + lhSize;
}
case IS_PCH:
@@ -3192,8 +3191,8 @@ size_t ZSTDv06_decodeLiteralsBlock(ZSTDv06_DCtx* dctx,
if (HUFv06_isError(errorCode)) return ERROR(corruption_detected);
}
dctx->litPtr = dctx->litBuffer;
dctx->litBufSize = ZSTDv06_BLOCKSIZE_MAX+WILDCOPY_OVERLENGTH;
dctx->litSize = litSize;
memset(dctx->litBuffer + dctx->litSize, 0, WILDCOPY_OVERLENGTH);
return litCSize + lhSize;
}
case IS_RAW:
@@ -3217,13 +3216,12 @@ size_t ZSTDv06_decodeLiteralsBlock(ZSTDv06_DCtx* dctx,
if (litSize+lhSize > srcSize) return ERROR(corruption_detected);
memcpy(dctx->litBuffer, istart+lhSize, litSize);
dctx->litPtr = dctx->litBuffer;
dctx->litBufSize = ZSTDv06_BLOCKSIZE_MAX+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;
}
@@ -3247,8 +3245,8 @@ size_t ZSTDv06_decodeLiteralsBlock(ZSTDv06_DCtx* dctx,
if (litSize > ZSTDv06_BLOCKSIZE_MAX) return ERROR(corruption_detected);
memset(dctx->litBuffer, istart[lhSize], litSize);
dctx->litPtr = dctx->litBuffer;
dctx->litBufSize = ZSTDv06_BLOCKSIZE_MAX+WILDCOPY_OVERLENGTH;
dctx->litSize = litSize;
memset(dctx->litBuffer + dctx->litSize, 0, WILDCOPY_OVERLENGTH);
return lhSize+1;
}
default:
@@ -3438,7 +3436,7 @@ static void ZSTDv06_decodeSequence(seq_t* seq, seqState_t* seqState)
size_t ZSTDv06_execSequence(BYTE* op,
BYTE* const oend, seq_t sequence,
const BYTE** litPtr, const BYTE* const litLimit_8,
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;
@@ -3451,7 +3449,7 @@ size_t ZSTDv06_execSequence(BYTE* op,
/* check */
if (oLitEnd > oend_8) return ERROR(dstSize_tooSmall); /* last match must start at a minimum distance of 8 from oend */
if (oMatchEnd > oend) return ERROR(dstSize_tooSmall); /* overwrite beyond dst buffer */
if (iLitEnd > litLimit_8) return ERROR(corruption_detected); /* over-read beyond lit buffer */
if (iLitEnd > litLimit) return ERROR(corruption_detected); /* over-read beyond lit buffer */
/* copy Literals */
ZSTDv06_wildcopy(op, *litPtr, sequence.litLength); /* note : oLitEnd <= oend-8 : no risk of overwrite beyond oend */
@@ -3523,7 +3521,6 @@ static size_t ZSTDv06_decompressSequences(
BYTE* const oend = ostart + maxDstSize;
BYTE* op = ostart;
const BYTE* litPtr = dctx->litPtr;
const BYTE* const litLimit_8 = litPtr + dctx->litBufSize - 8;
const BYTE* const litEnd = litPtr + dctx->litSize;
FSEv06_DTable* DTableLL = dctx->LLTable;
FSEv06_DTable* DTableML = dctx->MLTable;
@@ -3567,7 +3564,7 @@ static size_t ZSTDv06_decompressSequences(
pos, (U32)sequence.litLength, (U32)sequence.matchLength, (U32)sequence.offset);
#endif
{ size_t const oneSeqSize = ZSTDv06_execSequence(op, oend, sequence, &litPtr, litLimit_8, base, vBase, dictEnd);
{ size_t const oneSeqSize = ZSTDv06_execSequence(op, oend, sequence, &litPtr, litEnd, base, vBase, dictEnd);
if (ZSTDv06_isError(oneSeqSize)) return oneSeqSize;
op += oneSeqSize;
} }