avcodec/pngdec: Do not pass AVFrame into global header decode

The global header should not contain a frame, and decoding it
would result in leaks

Fixes: memleak
Fixes: 45982/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_APNG_fuzzer-6603443149340672

Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
(cherry picked from commit d31d4f32283f765c79d6e127d31ee2c37a0acef7)
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
This commit is contained in:
Michael Niedermayer 2023-04-16 15:06:59 +02:00
parent 941c6191fc
commit 8d93e90c6d
No known key found for this signature in database
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@ -632,6 +632,8 @@ static int decode_idat_chunk(AVCodecContext *avctx, PNGDecContext *s,
int ret;
size_t byte_depth = s->bit_depth > 8 ? 2 : 1;
if (!p)
return AVERROR_INVALIDDATA;
if (!(s->hdr_state & PNG_IHDR)) {
av_log(avctx, AV_LOG_ERROR, "IDAT without IHDR\n");
return AVERROR_INVALIDDATA;
@ -1382,6 +1384,9 @@ skip_tag:
}
exit_loop:
if (!p)
return AVERROR_INVALIDDATA;
if (avctx->codec_id == AV_CODEC_ID_PNG &&
avctx->skip_frame == AVDISCARD_ALL) {
return 0;
@ -1551,7 +1556,7 @@ static int decode_frame_apng(AVCodecContext *avctx,
s->zstream.zfree = ff_png_zfree;
bytestream2_init(&s->gb, avctx->extradata, avctx->extradata_size);
if ((ret = decode_frame_common(avctx, s, p, avpkt)) < 0)
if ((ret = decode_frame_common(avctx, s, NULL, avpkt)) < 0)
goto end;
}