Re: [PATCH 2/3] Fix avrcp unregister potential crash

[Johan Hedberg <johan.hedberg@gmail.com>]

Hi Lucas,

On Fri, May 18, 2012, Lucas De Marchi wrote:
> >> --- a/audio/avrcp.c
> >> +++ b/audio/avrcp.c
> >> @@ -1272,8 +1272,11 @@ void avrcp_unregister(const bdaddr_t *src)
> >>
> >>       servers = g_slist_remove(servers, server);
> >>
> >> -     remove_record_from_server(server->ct_record_id);
> >> -     remove_record_from_server(server->tg_record_id);
> >> +     if (server->ct_record_id)
> >> +             remove_record_from_server(server->ct_record_id);
> >> +
> >> +     if (server->tg_record_id)
> >> +             remove_record_from_server(server->tg_record_id);
> >>
> >>       avctp_unregister(&server->src);
> >>       g_free(server);
> >
> > I don't think the commit message for this patch is truthful. If you look
> > at the code the remove_record_from_server will return ENOENT if you pass
> > it a non-existent handle. I.e. it will not crash. Please fix the commit
> > message to reflect what exactly is being fixed (i.e. an unnecessary call
> > to remove_record_from_server if there is no record handle).
> 
> Then I don't see a reason: just let remove_record_from_server() fail ?
> 
> Chan, what are you fixing here?

As discussed on IRC (and Chanyeol should really have explained this in
the commit message) handle 0 is actually the SDP server's own "master"
record. So it is plausible that weird behavior might occur if trying to
remove it. Since this is a SDP server internal detail and it doesn't
really make sense to remove it I'm thinking that
remove_record_from_server should return EINVAL if passed a 0 value.

Johan