[FFmpeg-devel] [PATCH 07/28] changed: check return value of seeks to avoid messing up current stream location

[Reimar Döffinger]

On Wed, Jun 30, 2010 at 10:09:35AM +0100, Mans Rullgard wrote:
> From: Cory Fields <theuni-nospam- at xbmc.org>
> 
> ---
>  libavformat/avidec.c |    5 ++++-
>  1 files changed, 4 insertions(+), 1 deletions(-)
> 
> diff --git a/libavformat/avidec.c b/libavformat/avidec.c
> index befaa79..390d42f 100644
> --- a/libavformat/avidec.c
> +++ b/libavformat/avidec.c
> @@ -190,7 +190,10 @@ static int read_braindead_odml_indx(AVFormatContext *s, int frame_num){
>  
>              pos = url_ftell(pb);
>  
> -            url_fseek(pb, offset+8, SEEK_SET);
> +            if(url_fseek(pb, pos, SEEK_SET) < 0) {
> +                av_log(s, AV_LOG_ERROR, "Failed to restore position after reading index");
> +                return -1;
> +            }

when/why does this make a difference?

>              read_braindead_odml_indx(s, frame_num);

Hmm... an arbitrarily recursive function?
At least a DoS on that seems trivial... (I suspect this is not
the only place this can happen, IIRC mov allows something similar
by putting moov into moov into moov...).