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This is an automatically generated e-mail. To reply, visit:
<a href="https://reviewboard.asterisk.org/r/4599/">https://reviewboard.asterisk.org/r/4599/</a>
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<div>Review request for Asterisk Developers.</div>
<div>By Jaco Kroon.</div>
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<b style="color: #575012; font-size: 10pt; margin-top: 1.5em;">Bugs: </b>
<a href="https://issues.asterisk.org/jira/browse/21211">21211</a>
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<b style="color: #575012; font-size: 10pt;">Repository: </b>
Asterisk
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<h1 style="color: #575012; font-size: 10pt; margin-top: 1.5em;">Description </h1>
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<pre style="margin: 0; padding: 0; white-space: pre-wrap; white-space: -moz-pre-wrap; white-space: -pre-wrap; white-space: -o-pre-wrap; word-wrap: break-word;">chan_iax2.c, specifically in function iax2_poke_peer, a completely unprotected access to iaxs[peer->callno] is made. Specifically I had a segfault trigger on line 12230, an access to iaxs[peer->callno] - the second in a sequence, so peer->callno can definitely change between the two
It is my understanding that:
1. peer->callno can change outside of the function , thus it's probably unsafe to use the raw value as per lines 12223, 12229 and 12230. I believe this should be callno, and not peer->callno. Please correct me if I'm wrong. This can either happen by us calling iax2_destroy, or simply another thread also scheduling a POKE on the same peer.
2. All reads and writes to iaxs[X] should be protected by a lock of iaxsl[X]. Lines 12229 and 12230 violates this currently.
I suspect my crash resulted from a sequence where a POKE was in process of being scheduled, another thread then called iax2_poke_peer for the same peer, called iax2_destroy on the iaxs[] busy being set up, and boom major catastrophe.
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<h1 style="color: #575012; font-size: 10pt; margin-top: 1.5em;">Testing </h1>
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<pre style="margin: 0; padding: 0; white-space: pre-wrap; white-space: -moz-pre-wrap; white-space: -pre-wrap; white-space: -o-pre-wrap; word-wrap: break-word;">Been running since 11.2.1 with this patch, specifically 6/3/2013 (more than two years) in multiple production environments. Many fewer segfaults.</pre>
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<h1 style="color: #575012; font-size: 10pt; margin-top: 1.5em;">Diffs</b> </h1>
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<li>http://svn.asterisk.org/svn/asterisk/trunk/channels/chan_iax2.c <span style="color: grey">(434210)</span></li>
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<p><a href="https://reviewboard.asterisk.org/r/4599/diff/" style="margin-left: 3em;">View Diff</a></p>
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