54 lines
2.7 KiB
Diff
54 lines
2.7 KiB
Diff
From 05b6773fbcce1075edbe498a821f9a41249cf384 Mon Sep 17 00:00:00 2001
|
|
From: Nick Terrell <terrelln@fb.com>
|
|
Date: Mon, 14 Jun 2021 11:25:55 -0700
|
|
Subject: [PATCH 0759/1000] [fix] Add missing bounds checks during compression
|
|
|
|
* The block splitter missed a bounds check, so when the buffer is too small it
|
|
passes an erroneously large size to `ZSTD_entropyCompressSeqStore()`, which
|
|
can then write the compressed data past the end of the buffer. This is a new
|
|
regression in v1.5.0 when the block splitter is enabled. It is either enabled
|
|
explicitly, or implicitly when using the optimal parser and `ZSTD_compress2()`
|
|
or `ZSTD_compressStream*()`.
|
|
* `HUF_writeCTable_wksp()` omits a bounds check when calling
|
|
`HUF_compressWeights()`. If it is called with `dstCapacity == 0` it will pass
|
|
an erroneously large size to `HUF_compressWeights()`, which can then write
|
|
past the end of the buffer. This bug has been present for ages. However, I
|
|
believe that zstd cannot trigger the bug, because it never calls
|
|
`HUF_compress*()` with `dstCapacity == 0` because of [this check][1].
|
|
|
|
Credit to: Oss-Fuzz
|
|
|
|
[1]: https://github.com/facebook/zstd/blob/89127e5ee2f3c1e141668fa6d4ee91245f05d132/lib/compress/zstd_compress_literals.c#L100
|
|
---
|
|
lib/compress/huf_compress.c | 1 +
|
|
lib/compress/zstd_compress.c | 1 +
|
|
2 files changed, 2 insertions(+)
|
|
|
|
diff --git a/lib/compress/huf_compress.c b/lib/compress/huf_compress.c
|
|
index 485906e6..e9cb0bd5 100644
|
|
--- a/lib/compress/huf_compress.c
|
|
+++ b/lib/compress/huf_compress.c
|
|
@@ -133,6 +133,7 @@ size_t HUF_writeCTable_wksp(void* dst, size_t maxDstSize,
|
|
wksp->huffWeight[n] = wksp->bitsToWeight[CTable[n].nbBits];
|
|
|
|
/* attempt weights compression by FSE */
|
|
+ if (maxDstSize < 1) return ERROR(dstSize_tooSmall);
|
|
{ CHECK_V_F(hSize, HUF_compressWeights(op+1, maxDstSize-1, wksp->huffWeight, maxSymbolValue, &wksp->wksp, sizeof(wksp->wksp)) );
|
|
if ((hSize>1) & (hSize < maxSymbolValue/2)) { /* FSE compressed */
|
|
op[0] = (BYTE)hSize;
|
|
diff --git a/lib/compress/zstd_compress.c b/lib/compress/zstd_compress.c
|
|
index 70f16935..9e814e31 100644
|
|
--- a/lib/compress/zstd_compress.c
|
|
+++ b/lib/compress/zstd_compress.c
|
|
@@ -3486,6 +3486,7 @@ static size_t ZSTD_compressSeqStore_singleBlock(ZSTD_CCtx* zc, seqStore_t* const
|
|
if (isPartition)
|
|
ZSTD_seqStore_resolveOffCodes(dRep, cRep, seqStore, (U32)(seqStore->sequences - seqStore->sequencesStart));
|
|
|
|
+ RETURN_ERROR_IF(dstCapacity < ZSTD_blockHeaderSize, dstSize_tooSmall, "Block header doesn't fit");
|
|
cSeqsSize = ZSTD_entropyCompressSeqStore(seqStore,
|
|
&zc->blockState.prevCBlock->entropy, &zc->blockState.nextCBlock->entropy,
|
|
&zc->appliedParams,
|
|
--
|
|
2.23.0
|
|
|