From: Richard Mudgett <rmudgett@digium.com>
Date: Wed, 6 Jun 2012 21:32:09 +0000 (+0000)
Subject: Fix POTS flash hook to orignate a second call deadlock.
X-Git-Tag: 10.6.0-rc1~5
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=9fde37aec69b840b9cdc965f18801d91505c6811;p=thirdparty%2Fasterisk.git

Fix POTS flash hook to orignate a second call deadlock.

A deadlock can occur when a POTS phone tries to flash hook to originate a
second call for 3-way or transfer.  If another process is scanning the
channels container when the POTS line flash hooks then a deadlock will
occur.

* Release the channel and private locks when creating a new channel as a
result of a flash hook.

(closes issue ASTERISK-19842)
Reported by: rmudgett
Tested by: rmudgett
........

Merged revisions 368644 from http://svn.asterisk.org/svn/asterisk/branches/1.8


git-svn-id: https://origsvn.digium.com/svn/asterisk/branches/10@368645 65c4cc65-6c06-0410-ace0-fbb531ad65f3
---

diff --git a/channels/chan_dahdi.c b/channels/chan_dahdi.c
index 5eddc3f604..2ce2cf8719 100644
--- a/channels/chan_dahdi.c
+++ b/channels/chan_dahdi.c
@@ -8601,8 +8601,18 @@ static struct ast_frame *dahdi_handle_event(struct ast_channel *ast)
 						ast_log(LOG_WARNING, "Unable to allocate three-way subchannel\n");
 						goto winkflashdone;
 					}
-					/* Make new channel */
+
+					/*
+					 * Make new channel
+					 *
+					 * We cannot hold the p or ast locks while creating a new
+					 * channel.
+					 */
+					ast_mutex_unlock(&p->lock);
+					ast_channel_unlock(ast);
 					chan = dahdi_new(p, AST_STATE_RESERVED, 0, SUB_THREEWAY, 0, NULL);
+					ast_channel_lock(ast);
+					ast_mutex_lock(&p->lock);
 					if (p->dahditrcallerid) {
 						if (!p->origcid_num)
 							p->origcid_num = ast_strdup(p->cid_num);
diff --git a/channels/sig_analog.c b/channels/sig_analog.c
index aded6054d7..b3e75b18b8 100644
--- a/channels/sig_analog.c
+++ b/channels/sig_analog.c
@@ -3205,8 +3205,18 @@ static struct ast_frame *__analog_handle_event(struct analog_pvt *p, struct ast_
 						ast_log(LOG_WARNING, "Unable to allocate three-way subchannel\n");
 						goto winkflashdone;
 					}
-					/* Make new channel */
+
+					/*
+					 * Make new channel
+					 *
+					 * We cannot hold the p or ast locks while creating a new
+					 * channel.
+					 */
+					analog_unlock_private(p);
+					ast_channel_unlock(ast);
 					chan = analog_new_ast_channel(p, AST_STATE_RESERVED, 0, ANALOG_SUB_THREEWAY, NULL);
+					ast_channel_lock(ast);
+					analog_lock_private(p);
 					if (!chan) {
 						ast_log(LOG_WARNING,
 							"Cannot allocate new call structure on channel %d\n",