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| author | Andreas Cadhalpun <Andreas.Cadhalpun@googlemail.com> | 2015-03-02 20:47:57 +0100 |
|---|---|---|
| committer | Vittorio Giovara <vittorio.giovara@gmail.com> | 2015-03-08 19:21:49 +0000 |
| commit | 905172d75c9cfd93c757b09fa4b8afa0e926a13c (patch) | |
| tree | 7f4c8192e6f5ad9da02e8ded03e9af2d590dca9d | |
| parent | 8aee35acb1b40e51a4fc8d7f7c561088e25d6d2e (diff) | |
| download | ffmpeg-905172d75c9cfd93c757b09fa4b8afa0e926a13c.tar.gz | |
webp: validate the distance prefix code
According to the WebP Lossless Bitstream Specification the highest
allowed value for a prefix code is 39.
If prefix_code is too large, the calculated extra_bits has an invalid
value and triggers an assertion in get_bits.
Signed-off-by: Andreas Cadhalpun <Andreas.Cadhalpun@googlemail.com>
Signed-off-by: Anton Khirnov <anton@khirnov.net>
| -rw-r--r-- | libavcodec/webp.c | 5 |
1 files changed, 5 insertions, 0 deletions
diff --git a/libavcodec/webp.c b/libavcodec/webp.c index b98fa4dea4..58f7810793 100644 --- a/libavcodec/webp.c +++ b/libavcodec/webp.c @@ -688,6 +688,11 @@ static int decode_entropy_coded_image(WebPContext *s, enum ImageRole role, length = offset + get_bits(&s->gb, extra_bits) + 1; } prefix_code = huff_reader_get_symbol(&hg[HUFF_IDX_DIST], &s->gb); + if (prefix_code > 39) { + av_log(s->avctx, AV_LOG_ERROR, + "distance prefix code too large: %d\n", prefix_code); + return AVERROR_INVALIDDATA; + } if (prefix_code < 4) { distance = prefix_code + 1; } else { |