[FFmpeg-devel] [PATCH] lavd/lavfi: fix two memleaks.

Michael Niedermayer michaelni at gmx.at
Fri Dec 16 22:38:09 CET 2011


On Fri, Dec 16, 2011 at 09:54:52PM +0100, Nicolas George wrote:
> Le sextidi 26 frimaire, an CCXX, Michael Niedermayer a écrit :
> > this might lead to use after free in sink_buffer.c if iam not misssing
> > anything
>
> I looked into it before submitting, and I think that sink_buffer will not
> use it after init(), which is called by avfilter_graph_config. And valgrind
> did not show new errors after the new free.

My concern is that we pass a pointer into sink_buffer which keeps it
and uses it in an exported function (its query_formats() that gets
called by avfilter_graph_config())
and we free it outside while sink_buffer retains this now invalid
pointer.

AFAIK nothing calls query_formats() again and
nothing uses that pointer except query_formats(). But i think it
would be better if this pointer was set to NULL once it becomes
unavailable or if it would be freed only once sink_buffer is freed


>
> Stefano may be more competent to check this is correct.

It would be great if stefano could comment too

[...]

--
Michael     GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB

Those who are too smart to engage in politics are punished by being
governed by those who are dumber. -- Plato
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