diff options
Diffstat (limited to 'vendor/github.com/klauspost/compress/zstd/blockdec.go')
| -rw-r--r-- | vendor/github.com/klauspost/compress/zstd/blockdec.go | 18 |
1 files changed, 16 insertions, 2 deletions
diff --git a/vendor/github.com/klauspost/compress/zstd/blockdec.go b/vendor/github.com/klauspost/compress/zstd/blockdec.go index 607b62ee3..7d567a54a 100644 --- a/vendor/github.com/klauspost/compress/zstd/blockdec.go +++ b/vendor/github.com/klauspost/compress/zstd/blockdec.go @@ -167,6 +167,11 @@ func (b *blockDec) reset(br byteBuffer, windowSize uint64) error { } return ErrCompressedSizeTooBig } + // Empty compressed blocks must at least be 2 bytes + // for Literals_Block_Type and one for Sequences_Section_Header. + if cSize < 2 { + return ErrBlockTooSmall + } case blockTypeRaw: if cSize > maxCompressedBlockSize || cSize > int(b.WindowSize) { if debugDecoder { @@ -491,6 +496,9 @@ func (b *blockDec) decodeCompressed(hist *history) error { } func (b *blockDec) prepareSequences(in []byte, hist *history) (err error) { + if debugDecoder { + printf("prepareSequences: %d byte(s) input\n", len(in)) + } // Decode Sequences // https://github.com/facebook/zstd/blob/dev/doc/zstd_compression_format.md#sequences-section if len(in) < 1 { @@ -499,8 +507,6 @@ func (b *blockDec) prepareSequences(in []byte, hist *history) (err error) { var nSeqs int seqHeader := in[0] switch { - case seqHeader == 0: - in = in[1:] case seqHeader < 128: nSeqs = int(seqHeader) in = in[1:] @@ -517,6 +523,13 @@ func (b *blockDec) prepareSequences(in []byte, hist *history) (err error) { nSeqs = 0x7f00 + int(in[1]) + (int(in[2]) << 8) in = in[3:] } + if nSeqs == 0 && len(in) != 0 { + // When no sequences, there should not be any more data... + if debugDecoder { + printf("prepareSequences: 0 sequences, but %d byte(s) left on stream\n", len(in)) + } + return ErrUnexpectedBlockSize + } var seqs = &hist.decoders seqs.nSeqs = nSeqs @@ -635,6 +648,7 @@ func (b *blockDec) decodeSequences(hist *history) error { hist.decoders.seqSize = len(hist.decoders.literals) return nil } + hist.decoders.windowSize = hist.windowSize hist.decoders.prevOffset = hist.recentOffsets err := hist.decoders.decode(b.sequence) hist.recentOffsets = hist.decoders.prevOffset |