avcodec_open2() also called the AVCodec's close function if an error happened before init had ever been called if the AVCodec has the FF_CODEC_CAP_INIT_CLEANUP flag set. This is against the documentation of said flag: "The codec allows calling the close function for deallocation even if the init function returned a failure."
E.g. the SVQ3 decoder is not ready to be closed if init has never been called. Fixes: NULL dereference Fixes: 25762/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_SVQ3_fuzzer-5716279070294016 Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg Signed-off-by: Andreas Rheinhardt <andreas.rheinha...@gmail.com> --- If someone were to call avcodec_alloc_context3(NULL) and manually fill in avctx->codec, then the close function might even be called before avctx->priv_data has been allocated. libavcodec/utils.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/libavcodec/utils.c b/libavcodec/utils.c index cf0a55f26d..94b9e94584 100644 --- a/libavcodec/utils.c +++ b/libavcodec/utils.c @@ -931,6 +931,7 @@ FF_ENABLE_DEPRECATION_WARNINGS || avci->frame_thread_encoder)) { ret = avctx->codec->init(avctx); if (ret < 0) { + codec_init_ok = -1; goto free_and_end; } codec_init_ok = 1; @@ -1022,8 +1023,8 @@ end: return ret; free_and_end: if (avctx->codec && avctx->codec->close && - (codec_init_ok || - (avctx->codec->caps_internal & FF_CODEC_CAP_INIT_CLEANUP))) + (codec_init_ok > 0 || (codec_init_ok < 0 && + avctx->codec->caps_internal & FF_CODEC_CAP_INIT_CLEANUP))) avctx->codec->close(avctx); if (HAVE_THREADS && avci->thread_ctx) -- 2.25.1 _______________________________________________ ffmpeg-devel mailing list ffmpeg-devel@ffmpeg.org https://ffmpeg.org/mailman/listinfo/ffmpeg-devel To unsubscribe, visit link above, or email ffmpeg-devel-requ...@ffmpeg.org with subject "unsubscribe".
