Module: libav Branch: master Commit: 4f2ee9daeedec636fb4fe953a1e0990a7102d5eb
Author: Andreas Cadhalpun <[email protected]> Committer: Anton Khirnov <[email protected]> Date: Mon Mar 2 20:47:57 2015 +0100 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 <[email protected]> Signed-off-by: Anton Khirnov <[email protected]> --- libavcodec/webp.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/libavcodec/webp.c b/libavcodec/webp.c index b98fa4d..58f7810 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 { _______________________________________________ libav-commits mailing list [email protected] https://lists.libav.org/mailman/listinfo/libav-commits
