[FFmpeg-devel] [PATCH] avformat/rtmpproto: Don't free AVOpt-strings manually, fix crash

[Steven Liu]

Liu Steven <lq at chinaffmpeg.org> 于2024年3月31日周日 10:16写道：
>
>
>
> > On Mar 30, 2024, at 12:21, Andreas Rheinhardt <andreas.rheinhardt at outlook.com> wrote:
> >
> > Andreas Rheinhardt:
> Hi Andreas,
>
> >> Besides being redundant, freeing manually is actually harmful here,
> >> as rtmp_close() may call gen_fcunpublish_stream() which dereferences
> >> rt->playpath.
> >>
> >> Reported-by: Armin Hasitzka <armin at grabyo.com>
> >> Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt at outlook.com>
> >> ---
> >> libavformat/rtmpproto.c | 3 ---
> >> 1 file changed, 3 deletions(-)
> >>
> >> diff --git a/libavformat/rtmpproto.c b/libavformat/rtmpproto.c
> >> index 4b01b67d28..b1d73b3d75 100644
> >> --- a/libavformat/rtmpproto.c
> >> +++ b/libavformat/rtmpproto.c
> >> @@ -2917,9 +2917,6 @@ reconnect:
> >>     return 0;
> >>
> >> fail:
> >> -    av_freep(&rt->playpath);
> >> -    av_freep(&rt->tcurl);
> >> -    av_freep(&rt->flashver);
> >>     av_dict_free(opts);
> >>     rtmp_close(s);
> >>     return ret;
> >
> > I am pinging this and explicitly cc'ing Steven Liu, whose commit
> > 991cf95fdeebc3af added the av_freeps to be removed above. Steven, did
> > you just feel that there was missing freeing code for the buffers above
> > or was there an actually confirmed memleak (there shouldn't be)?
>
> Confirmed memleak, but it’s long time i cannot sure how to reproduce that, I test rtmp those years use SRS.
May be the memleak was reported by fuzz program, the test case can
injection failed result make the workflow into the failed,
The gen_fcunpublish_stream should after av_malloc rt->playpath,
rt->tcurl, rt->flashver av_malloc, and there cloud get failed in the
gen_connect.

Steven
Thanks