[asterisk-bugs] [Asterisk 0018403]: [patch] Deadlock on SIP blind transfer (REFER)

[Asterisk Bug Tracker]

A NOTE has been added to this issue. 
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https://issues.asterisk.org/view.php?id=18403 
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Reported By:                jthurman
Assigned To:                jpeeler
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Project:                    Asterisk
Issue ID:                   18403
Category:                   Channels/chan_sip/Transfers
Reproducibility:            always
Severity:                   major
Priority:                   normal
Status:                     acknowledged
Target Version:             1.8.3
Asterisk Version:           SVN 
JIRA:                       SWP-2667 
Regression:                 No 
Reviewboard Link:            
SVN Branch (only for SVN checkouts, not tarball releases): 1.8 
SVN Revision (number only!): 296824 
Request Review:              
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Date Submitted:             2010-11-30 18:25 CST
Last Modified:              2011-01-13 17:50 CST
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Summary:                    [patch] Deadlock on SIP blind transfer (REFER)
Description: 
All SIP:
- A calls B
- B blind-transfers A to C (Using REFER)
- Asterisk stops responding to SIP requests (Deadlocked)

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Relationships       ID      Summary
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related to          0018554 SIP channel tried to release unowned mu...
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 (0130473) jpeeler (administrator) - 2011-01-13 17:50
 https://issues.asterisk.org/view.php?id=18403#c130473 
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After studying 20110103-blind_deadlock.diff, it looks like the right fix. I
made two modifications: 1) moved unlocking order just to enforce good
habits 2) changed locking the sip private until later so the channel lock
doesn't need to be reaquired in handle_request_refer
(pbx_builtin_setvar_helper locks the channel itself). 

Issue History 
Date Modified    Username       Field                    Change               
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2011-01-13 17:50 jpeeler        Note Added: 0130473                          
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