[Vortex] TLS Failure Segfault

[Francis Brosnan Blazquez]

> Hello all,

Hi Jason,

> I am experiencing an issue with a TLS failure, which I believe I have
> resolved, but wanted to get some clarification.

OK,

> Basically, we are getting a segfault when attempting a TLS connection
> that fails and a subsequent call to vortex_connection_is_ok, with
> axl_true for destroying the connection if not ok.  What appears to be
> happening is when the TLS connection is attempted, the original
> connection is destroyed and then an invalid pointer is returned to the
> original calling process when TLS fails.  I believe this can be
> remedied by moving the original connection unref to the end of
> vortex_tls_invoke_tls_activation.
> 
> I have attached a patch for your review.

I've been reviewing the patch and I see two issues:

1) Technically is not possible to receive a wrong connection pointer
   even after a TLS failure. This is because a new connection object is
   notified via __vortex_tls_start_negotiation_close_and_notify in all
   exit branches of that function. This means a good connection
   reference is always received. 

   The only way to receive a wrong pointer is that the following is
   failling (around vortex_tls.c:982) which is not checked:

   connection = vortex_connection_new_empty_from_connection (ctx, socket, connection_aux, VortexRoleInitiator);

   Now, the function also checks that pointer but I suspect this
   is not the case (svn rev 4995).

2) The patch proposes to move the unref code until the end, but that
   will cause leaks due to all wrong branches before (wrong greetings,  
   TLS handshake failure, ....) where the reference is not finished.

Just a question about your description. What's the connection being
checked with vortex_connection_is_ok (conn, axl_true) after tls failure?
The one returned by the tls activation or the starting connection?

You must forget about the starting connection when you call to activate
TLS because that function may replace your reference, even after failure
(something may go wrong after TLS finished right, for example BEEP
session doesn't agree)....

Best Regards,

> Jason
> 
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-- 
Francis Brosnan Blázquez <francis.brosnan at aspl.es>
ASPL
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