[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:                
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Project:                    Asterisk
Issue ID:                   18403
Category:                   Channels/chan_sip/Transfers
Reproducibility:            always
Severity:                   major
Priority:                   normal
Status:                     acknowledged
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:              2010-12-24 18:32 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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 (0129957) kkm (reporter) - 2010-12-24 18:32
 https://issues.asterisk.org/view.php?id=18403#c129957 
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Oh, what a catch-22! handle_request_refer()'s logic distills down to

if (ast_parking_ext_valid()) {  // channel lock must be released before
the call 
  do_something()
  return;
}
pbx_builtin_setvar_helper(); // channel lock must still be held to call
that

Original code calls ast_parking_ext_valid() with the lock held, and
deadlocks.

Your patch calls pbx_builtin_setvar_helper() after having released the
lock, and deadlocks. 

Issue History 
Date Modified    Username       Field                    Change               
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2010-12-24 18:32 kkm            Note Added: 0129957                          
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