avcodec/pngdec: Only allow one IHDR chunk

Multiple IHDR chunks are forbidden in PNG
Fixes inconsistency and out of array accesses

Fixes: asan_heap-oob_4d5c5a_1738_cov_2638287726_c-m2-8f2b481b7fd9bd745e620b7c01a18df2.png

Found-by: Mateusz "j00ru" Jurczyk and Gynvael Coldwind
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
This commit is contained in:
Michael Niedermayer 2015-06-29 21:08:05 +02:00
parent 9842d6707f
commit 47f4e2d896

View File

@ -542,6 +542,11 @@ static int decode_ihdr_chunk(AVCodecContext *avctx, PNGDecContext *s,
return AVERROR_INVALIDDATA;
}
if (s->state & PNG_IHDR) {
av_log(avctx, AV_LOG_ERROR, "Multiple IHDR\n");
return AVERROR_INVALIDDATA;
}
s->width = bytestream2_get_be32(&s->gb);
s->height = bytestream2_get_be32(&s->gb);
if (av_image_check_size(s->width, s->height, 0, avctx)) {