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
@@ -2731,7 +2731,6 @@ struct ZSTDv05_DCtx_s
ZSTDv05_dStage stage;
U32 flagStaticTables;
const BYTE* litPtr;
size_t litBufSize;
size_t litSize;
BYTE litBuffer[BLOCKSIZE + WILDCOPY_OVERLENGTH];
BYTE headerBuffer[ZSTDv05_frameHeaderSize_max];
@@ -2978,8 +2977,8 @@ size_t ZSTDv05_decodeLiteralsBlock(ZSTDv05_DCtx* dctx,
return ERROR(corruption_detected);
dctx->litPtr = dctx->litBuffer;
dctx->litBufSize = BLOCKSIZE+8;
dctx->litSize = litSize;
memset(dctx->litBuffer + dctx->litSize, 0, WILDCOPY_OVERLENGTH);
return litCSize + lhSize;
}
case IS_PCH:
@@ -3002,8 +3001,8 @@ size_t ZSTDv05_decodeLiteralsBlock(ZSTDv05_DCtx* dctx,
if (HUFv05_isError(errorCode)) return ERROR(corruption_detected);
dctx->litPtr = dctx->litBuffer;
dctx->litBufSize = BLOCKSIZE+WILDCOPY_OVERLENGTH;
dctx->litSize = litSize;
memset(dctx->litBuffer + dctx->litSize, 0, WILDCOPY_OVERLENGTH);
return litCSize + lhSize;
}
case IS_RAW:
@@ -3028,13 +3027,12 @@ size_t ZSTDv05_decodeLiteralsBlock(ZSTDv05_DCtx* dctx,
if (litSize+lhSize > srcSize) return ERROR(corruption_detected);
memcpy(dctx->litBuffer, istart+lhSize, litSize);
dctx->litPtr = dctx->litBuffer;
dctx->litBufSize = BLOCKSIZE+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;
}
@@ -3059,8 +3057,8 @@ size_t ZSTDv05_decodeLiteralsBlock(ZSTDv05_DCtx* dctx,
if (litSize > BLOCKSIZE) return ERROR(corruption_detected);
memset(dctx->litBuffer, istart[lhSize], litSize);
dctx->litPtr = dctx->litBuffer;
dctx->litBufSize = BLOCKSIZE+WILDCOPY_OVERLENGTH;
dctx->litSize = litSize;
memset(dctx->litBuffer + dctx->litSize, 0, WILDCOPY_OVERLENGTH);
return lhSize+1;
}
default:
@@ -3289,7 +3287,7 @@ static void ZSTDv05_decodeSequence(seq_t* seq, seqState_t* seqState)
static size_t ZSTDv05_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)
{
static const int dec32table[] = { 0, 1, 2, 1, 4, 4, 4, 4 }; /* added */
@@ -3304,7 +3302,7 @@ static size_t ZSTDv05_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 (litEnd > litLimit_8) return ERROR(corruption_detected); /* risk read beyond lit buffer */
if (litEnd > litLimit) return ERROR(corruption_detected); /* risk read beyond lit buffer */
/* copy Literals */
ZSTDv05_wildcopy(op, *litPtr, sequence.litLength); /* note : oLitEnd <= oend-8 : no risk of overwrite beyond oend */
@@ -3378,7 +3376,6 @@ static size_t ZSTDv05_decompressSequences(
BYTE* const oend = ostart + maxDstSize;
size_t errorCode, dumpsLength;
const BYTE* litPtr = dctx->litPtr;
const BYTE* const litLimit_8 = litPtr + dctx->litBufSize - 8;
const BYTE* const litEnd = litPtr + dctx->litSize;
int nbSeq;
const BYTE* dumps;
@@ -3416,7 +3413,7 @@ static size_t ZSTDv05_decompressSequences(
size_t oneSeqSize;
nbSeq--;
ZSTDv05_decodeSequence(&sequence, &seqState);
oneSeqSize = ZSTDv05_execSequence(op, oend, sequence, &litPtr, litLimit_8, base, vBase, dictEnd);
oneSeqSize = ZSTDv05_execSequence(op, oend, sequence, &litPtr, litEnd, base, vBase, dictEnd);
if (ZSTDv05_isError(oneSeqSize)) return oneSeqSize;
op += oneSeqSize;
}