[asterisk-bugs] [Asterisk 0016840]: [patch] Deadlock in chan_local when obtaining locks on local_pvt->lock
Asterisk Bug Tracker
noreply at bugs.digium.com
Wed Feb 17 14:30:57 CST 2010
The following issue is now READY FOR TESTING.
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https://issues.asterisk.org/view.php?id=16840
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Reported By: bzing2
Assigned To:
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Project: Asterisk
Issue ID: 16840
Category: Channels/chan_local
Reproducibility: random
Severity: major
Priority: normal
Status: ready for testing
Asterisk Version: 1.6.2.2
JIRA: SWP-925
Regression: No
Reviewboard Link:
SVN Branch (only for SVN checkouts, not tarball releases): N/A
SVN Revision (number only!):
Request Review:
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Date Submitted: 2010-02-16 11:40 CST
Last Modified: 2010-02-17 14:30 CST
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Summary: [patch] Deadlock in chan_local when obtaining locks
on local_pvt->lock
Description:
Deadlock condition in chan_local when two brideged threads attempt to
obtain
locks to eachothers local_pvt structures in the opposite order. All
processing of SIP traffic halts when an attempt is made to hangup the
call.
Thread A obtains a lock to its local_pvt->lock when in local_write. When
in check_bridge a call is made to ast_bridged_channel, this in turn calls
local_bridgedchannel which attempts to obtain a lock on the bridged
channels
local_pvt->lock.
Thread B follows a similar path. It holds its own lock, and during a call
to
ast_channel_masquerade again local_bridgedchannel is called. This
attempts to
obtain a lock to the bridged channel.
At this point either side has deadlocked. Then a user attempts to hangup
the
call and again local_bridgedchannel is called, and blocks while attempting
to
get the lock. Unfortunalty sip netlock is held and everything grinds to a
halt.
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Issue History
Date Modified Username Field Change
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2010-02-17 14:30 lmadsen Status new => ready for
testing
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