avcodec/iff: finetune the palette size check in the mask case

Fixes: out of array access
Fixes: 15381/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_IFF_ILBM_fuzzer-5668057826983936

Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg
Reviewed-by: Peter Ross <pross@xvid.org>
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
This commit is contained in:
Michael Niedermayer 2019-06-22 21:17:52 +02:00
parent 92e8db532c
commit 0f9789c8e3

View File

@ -1514,7 +1514,7 @@ static int decode_frame(AVCodecContext *avctx,
buf_size -= bytestream2_tell(gb);
desc = av_pix_fmt_desc_get(avctx->pix_fmt);
if (!s->init && avctx->bits_per_coded_sample <= 8 &&
if (!s->init && avctx->bits_per_coded_sample <= 8 - (s->masking == MASK_HAS_MASK) &&
avctx->pix_fmt == AV_PIX_FMT_PAL8) {
if ((res = cmap_read_palette(avctx, (uint32_t *)frame->data[1])) < 0)
return res;