From 81503ac58a763a36b1f57264013b1e76acb62b68 Mon Sep 17 00:00:00 2001 From: Michael Niedermayer Date: Wed, 9 Sep 2020 23:13:02 +0200 Subject: [PATCH] avcodec/utils: Require a non zero channels unless AV_CODEC_CAP_CHANNEL_CONF is set This avoids per codec checks for channels not being 0 Fixes: division by 0 Fixes: 25419/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_FASTAUDIO_fuzzer-5632544761184256 Fixes: 25433/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_FASTAUDIO_fuzzer-6215671900536832 Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg Suggested-by: Paul B Mahol See: [FFmpeg-devel] [PATCH 1/3] avcodec/fastaudio: Check channel Reviewed-by: Paul B Mahol Signed-off-by: Michael Niedermayer --- libavcodec/utils.c | 9 +++++++++ 1 file changed, 9 insertions(+) diff --git a/libavcodec/utils.c b/libavcodec/utils.c index 3232a242c0..45295dd3ce 100644 --- a/libavcodec/utils.c +++ b/libavcodec/utils.c @@ -667,6 +667,15 @@ int attribute_align_arg avcodec_open2(AVCodecContext *avctx, const AVCodec *code ret = AVERROR(EINVAL); goto free_and_end; } + if (av_codec_is_decoder(codec) && + codec->type == AVMEDIA_TYPE_AUDIO && + !(codec->capabilities & AV_CODEC_CAP_CHANNEL_CONF) && + avctx->channels == 0) { + av_log(avctx, AV_LOG_ERROR, "Decoder requires channel count but channels not set\n"); + ret = AVERROR(EINVAL); + goto free_and_end; + } + if (avctx->sample_rate < 0) { av_log(avctx, AV_LOG_ERROR, "Invalid sample rate: %d\n", avctx->sample_rate); ret = AVERROR(EINVAL); -- GitLab