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| author | Andreas Cadhalpun <Andreas.Cadhalpun@googlemail.com> | 2015-03-02 20:47:57 +0100 |
|---|---|---|
| committer | Anton Khirnov <anton@khirnov.net> | 2015-03-05 14:49:16 +0100 |
| commit | 4f2ee9daeedec636fb4fe953a1e0990a7102d5eb (patch) | |
| tree | 192f60c813f7afe0d17315feb24b538cb033404f /libavcodec/webp.c | |
| parent | 66624ed6319cb1a959256fe1a717fec5b748fbfa (diff) | |
| download | ffmpeg-4f2ee9daeedec636fb4fe953a1e0990a7102d5eb.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>
Diffstat (limited to 'libavcodec/webp.c')
| -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 { |