From d31d4f32283f765c79d6e127d31ee2c37a0acef7 Mon Sep 17 00:00:00 2001 From: Michael Niedermayer Date: Sun, 16 Apr 2023 15:06:59 +0200 Subject: [PATCH] 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 --- libavcodec/pngdec.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) diff --git a/libavcodec/pngdec.c b/libavcodec/pngdec.c index 81c9892d35..0369d1c449 100644 --- a/libavcodec/pngdec.c +++ b/libavcodec/pngdec.c @@ -734,6 +734,8 @@ 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; @@ -1515,6 +1517,9 @@ static int decode_frame_common(AVCodecContext *avctx, PNGDecContext *s, } exit_loop: + if (!p) + return AVERROR_INVALIDDATA; + if (avctx->codec_id == AV_CODEC_ID_PNG && avctx->skip_frame == AVDISCARD_ALL) { return 0; @@ -1727,7 +1732,7 @@ static int decode_frame_apng(AVCodecContext *avctx, AVFrame *p, if ((ret = inflateReset(&s->zstream.zstream)) != Z_OK) return AVERROR_EXTERNAL; 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) return ret; }