[FFmpeg-devel] [PATCH]lavc/frame_thread_encoder: Do not memcpy() from NULL

[Carl Eugen Hoyos]

Am So., 7. Juli 2019 um 14:04 Uhr schrieb Mark Thompson <sw at jkqxz.net>:
>
> On 02/07/2019 10:44, Carl Eugen Hoyos wrote:
> > Am Di., 2. Juli 2019 um 08:31 Uhr schrieb Reimar Döffinger
> > <Reimar.Doeffinger at gmx.de>:
> >>
> >> On 01.07.2019, at 00:51, Carl Eugen Hoyos <ceffmpeg at gmail.com> wrote:
> >
> >>> I believe attached patch fixes undefined behaviour and ticket #7981.
> >>
> >> Same here, I think it makes more sense to check the "size" instead of the pointer.
> >
> > True, new patch attached.
> >
> >> But I also suspect we might want to think of a way to not need all these explicit checks all over.
> >
> > There are some places, but not so many afair.
> >
> > Carl Eugen
> >
> >
> > From 263adbc580ecbc67edbdc6d0f89e91a484bd520f Mon Sep 17 00:00:00 2001
> > From: Carl Eugen Hoyos <ceffmpeg at gmail.com>
> > Date: Tue, 2 Jul 2019 11:42:32 +0200
> > Subject: [PATCH] lavc/frame_thread_encoder: Do not memcpy() from NULL.
> >
> > Fixes ticket #7981.
> > ---
> >  libavcodec/frame_thread_encoder.c | 3 ++-
> >  1 file changed, 2 insertions(+), 1 deletion(-)
> >
> > diff --git a/libavcodec/frame_thread_encoder.c b/libavcodec/frame_thread_encoder.c
> > index 55756c4c54..949bc69f81 100644
> > --- a/libavcodec/frame_thread_encoder.c
> > +++ b/libavcodec/frame_thread_encoder.c
> > @@ -209,8 +209,9 @@ int ff_frame_thread_encoder_init(AVCodecContext *avctx, AVDictionary *options){
> >              int ret = av_opt_copy(thread_avctx->priv_data, avctx->priv_data);
> >              if (ret < 0)
> >                  goto fail;
> > -        } else
> > +        } else if (avctx->codec->priv_data_size) {
> >              memcpy(thread_avctx->priv_data, avctx->priv_data, avctx->codec->priv_data_size);
> > +        }
> >          thread_avctx->thread_count = 1;
> >          thread_avctx->active_thread_type &= ~FF_THREAD_FRAME;
> >
> > --
> > 2.22.0
> >
>
> This is a good idea anyway regardless of the outcome of the av_memcpy() discussion.  LGTM.

Patch applied.

Thank you, Carl Eugen