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
+9 -12
View File
@@ -104,7 +104,6 @@ struct ZSTD_DCtx_s
U32 dictID;
const BYTE* litPtr;
ZSTD_customMem customMem;
size_t litBufSize;
size_t litSize;
size_t rleSize;
BYTE litBuffer[ZSTD_BLOCKSIZE_ABSOLUTEMAX + WILDCOPY_OVERLENGTH];
@@ -429,10 +428,10 @@ size_t ZSTD_decodeLiteralsBlock(ZSTD_DCtx* dctx,
return ERROR(corruption_detected);
dctx->litPtr = dctx->litBuffer;
dctx->litBufSize = ZSTD_BLOCKSIZE_ABSOLUTEMAX+WILDCOPY_OVERLENGTH;
dctx->litSize = litSize;
dctx->litEntropy = 1;
if (litEncType==set_compressed) dctx->HUFptr = dctx->hufTable;
memset(dctx->litBuffer + dctx->litSize, 0, WILDCOPY_OVERLENGTH);
return litCSize + lhSize;
}
@@ -459,13 +458,12 @@ size_t ZSTD_decodeLiteralsBlock(ZSTD_DCtx* dctx,
if (litSize+lhSize > srcSize) return ERROR(corruption_detected);
memcpy(dctx->litBuffer, istart+lhSize, litSize);
dctx->litPtr = dctx->litBuffer;
dctx->litBufSize = ZSTD_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;
}
@@ -492,8 +490,8 @@ size_t ZSTD_decodeLiteralsBlock(ZSTD_DCtx* dctx,
if (litSize > ZSTD_BLOCKSIZE_ABSOLUTEMAX) return ERROR(corruption_detected);
memset(dctx->litBuffer, istart[lhSize], litSize);
dctx->litPtr = dctx->litBuffer;
dctx->litBufSize = ZSTD_BLOCKSIZE_ABSOLUTEMAX+WILDCOPY_OVERLENGTH;
dctx->litSize = litSize;
memset(dctx->litBuffer + dctx->litSize, 0, WILDCOPY_OVERLENGTH);
return lhSize+1;
}
default:
@@ -867,7 +865,7 @@ static seq_t ZSTD_decodeSequence(seqState_t* seqState)
FORCE_NOINLINE
size_t ZSTD_execSequenceLast7(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;
@@ -879,7 +877,7 @@ size_t ZSTD_execSequenceLast7(BYTE* op,
/* check */
if (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 */
if (oLitEnd <= oend_w) return ERROR(GENERIC); /* Precondition */
/* copy literals */
@@ -914,7 +912,7 @@ size_t ZSTD_execSequenceLast7(BYTE* op,
FORCE_INLINE
size_t ZSTD_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;
@@ -926,8 +924,8 @@ size_t ZSTD_execSequence(BYTE* op,
/* check */
if (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 (oLitEnd>oend_w) return ZSTD_execSequenceLast7(op, oend, sequence, litPtr, litLimit_w, base, vBase, dictEnd);
if (iLitEnd > litLimit) return ERROR(corruption_detected); /* over-read beyond lit buffer */
if (oLitEnd>oend_w) return ZSTD_execSequenceLast7(op, oend, sequence, litPtr, litLimit, base, vBase, dictEnd);
/* copy Literals */
ZSTD_copy8(op, *litPtr);
@@ -1002,7 +1000,6 @@ static size_t ZSTD_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;
const BYTE* const base = (const BYTE*) (dctx->base);
const BYTE* const vBase = (const BYTE*) (dctx->vBase);
@@ -1028,7 +1025,7 @@ static size_t ZSTD_decompressSequences(
for ( ; (BIT_reloadDStream(&(seqState.DStream)) <= BIT_DStream_completed) && nbSeq ; ) {
nbSeq--;
{ seq_t const sequence = ZSTD_decodeSequence(&seqState);
size_t const oneSeqSize = ZSTD_execSequence(op, oend, sequence, &litPtr, litLimit_w, base, vBase, dictEnd);
size_t const oneSeqSize = ZSTD_execSequence(op, oend, sequence, &litPtr, litEnd, base, vBase, dictEnd);
if (ZSTD_isError(oneSeqSize)) return oneSeqSize;
op += oneSeqSize;
} }