[FFmpeg-devel] [PATCH] Fix double free causing segmentation faults when accessing unavailable v4l devices

[Michael Niedermayer]

On Tue, Jul 15, 2008 at 09:39:01PM +0200, Stefano Sabatini wrote:
> Hi all, as in subject,
> you may experience the crashes for example with:
> ffmpeg -f video4linux2 -s 640x480 -r 25 -i /dev/video0
> 
> if there is no video4linux device connected to the machine (no
> /dev/video0 file).
> 
> This happens because the v4l2?_read_header() functions call av_free() on
> the new stream, then av_open_input_stream() call av_free() again in case
> of failure on the already alloced stream:
> 
>  fail:
>     if (ic) {
>         int i;
>         av_freep(&ic->priv_data);
>         for(i=0;i<ic->nb_streams;i++) {
>             AVStream *st = ic->streams[i];
>             if (st) {
>                 av_free(st->priv_data);
>                 av_free(st->codec->extradata);
>             }
>             av_free(st);
>         }
>     }
>     av_free(ic);
>     *ic_ptr = NULL;
>     return err;
> 
> Another possible solution could be to use avfreep(&st) in 
> v4l?.c, but I think this solution is more correct.

patches ok

[...]
-- 
Michael     GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB

Many that live deserve death. And some that die deserve life. Can you give
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