[vlc-devel] [PATCH] stream_filter: fix null dereference by modules/demux/mpeg/ts.c

[Rémi Denis-Courmont]

Le sunnuntaina 23. elokuuta 2020, 15.52.02 EEST Francois Cartegnie a écrit :
> Le 21/08/2020 à 20:54, Rémi Denis-Courmont a écrit :
> > Le vendredi 21 août 2020, 18:01:17 EEST Akinobu Mita a écrit :
> >> This revers commit daeddd9bc724da5aa3c364c5b382da963f92b5b8
> >> ("stream_filter: remove tautology test").
> > 
> > I don't follow. A stream filter should always have a constant and non-NULL
> > ->s, deleted by the owner of the stream filter by the patched code.
> > 
> > This sounds like a bug in the TS plugin, not the code.
> 
> The root issue is that we can't "unplug" a consumer stream filter
> without having stream_Delete() recursing on parents.

That makes no sense. vlc_stream_Delete() deletes a stream and its underlying 
resources, whether that's a filter or anything else.
 
Even if you know that the stream is actually stream filter, you don't know what 
state it left the underlying stream in (e.g., set some PID filtering), so 
there's nothing you can and should do with it.

This code is breaking an abstraction on *both* sides really.

-- 
Rémi Denis-Courmont
http://www.remlab.net/