avcodec/pngdec: Check that previous_picture has same w/h/format

Fixes: out of array access
Fixes: 15540/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_APNG_fuzzer-5684905029140480

Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg
Reviewed-by: Paul B Mahol <onemda@gmail.com>
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
(cherry picked from commit 18c808ffbe)
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
This commit is contained in:
Michael Niedermayer 2019-07-10 23:02:36 +02:00
parent 40c3eedd40
commit f2d81316e8

View File

@ -1248,6 +1248,9 @@ exit_loop:
if (CONFIG_PNG_DECODER && avctx->codec_id != AV_CODEC_ID_APNG)
handle_p_frame_png(s, p);
else if (CONFIG_APNG_DECODER &&
s->previous_picture.f->width == p->width &&
s->previous_picture.f->height== p->height &&
s->previous_picture.f->format== p->format &&
avctx->codec_id == AV_CODEC_ID_APNG &&
(ret = handle_p_frame_apng(avctx, s, p)) < 0)
goto fail;