[asterisk-dev] 0017234: [patch] Memory leak in manager.c - eqe should never be null!

[Dave Woolley]

I don't believe the latest fix to issues 0017234
<https://issues.asterisk.org/view.php?id=17234> can have addressed the
fundamental cause of the actual crash.  That's because it is defending
against a condition that should be impossible.  session->last_ev is,
currently, always set non-null before the session is added to the
sessions list and should never be allowed to go null again once it is on
that list.  The purge_sessions function, picks it from the sessions
list, so should never receive a null last_ev pointer, so it looks to me
that suppressing the use count decrement when it is null is simply
papering over cracks.

I can't work out how last_ev could get null.

Unless I can understand why it gets null, I can't be sure that the same
problem won't occur for TCP AMI, and if it can, know how to test that it
is fixed for our usage. 

As this is a public list, please ignore the confidentiality part of the
following.
-- 
David Woolley
BTS Holdings Plc
Tel: +44 (0)20 8401 9000 Fax: +44 (0)20 8401 9100
http://www.bts.co.uk 


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