From 9b31bd3cd83b50e0843f42b70d5e111287fa8107 Mon Sep 17 00:00:00 2001
From: Richard Mudgett <rmudgett@digium.com>
Date: Wed, 14 Mar 2012 22:38:29 +0000
Subject: [PATCH] Fix deadlock potential with some
ast_indicate/ast_indicate_data calls.
Calling ast_indicate()/ast_indicate_data() with the channel lock held can
result in a deadlock with a local channel because of how local channels
need to avoid deadlock.
........
Merged revisions 359451 from http://svn.asterisk.org/svn/asterisk/branches/1.8
........
Merged revisions 359453 from http://svn.asterisk.org/svn/asterisk/branches/10
git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@359455 65c4cc65-6c06-0410-ace0-fbb531ad65f3
---
channels/chan_agent.c | 4 ----
include/asterisk/channel.h | 2 ++
main/channel.c | 36 ++++++++++++++++++++++++++++++------
3 files changed, 32 insertions(+), 10 deletions(-)
diff --git a/channels/chan_agent.c b/channels/chan_agent.c
index 0c79a66de3..01938396d0 100644
--- a/channels/chan_agent.c
+++ b/channels/chan_agent.c
@@ -967,9 +967,7 @@ static int agent_hangup(struct ast_channel *ast)
ast_channel_internal_bridged_channel_set(p->chan, NULL);
/* If they're dead, go ahead and hang up on the agent now */
if (p->dead) {
- ast_channel_lock(p->chan);
ast_softhangup(p->chan, AST_SOFTHANGUP_EXPLICIT);
- ast_channel_unlock(p->chan);
} else if (p->loginstart) {
indicate_chan = ast_channel_ref(p->chan);
tmp_moh = ast_strdupa(p->moh);
@@ -978,11 +976,9 @@ static int agent_hangup(struct ast_channel *ast)
ast_mutex_unlock(&p->lock);
if (indicate_chan) {
- ast_channel_lock(indicate_chan);
ast_indicate_data(indicate_chan, AST_CONTROL_HOLD,
S_OR(tmp_moh, NULL),
!ast_strlen_zero(tmp_moh) ? strlen(tmp_moh) + 1 : 0);
- ast_channel_unlock(indicate_chan);
indicate_chan = ast_channel_unref(indicate_chan);
}
diff --git a/include/asterisk/channel.h b/include/asterisk/channel.h
index 292640bb43..8e438bbd59 100644
--- a/include/asterisk/channel.h
+++ b/include/asterisk/channel.h
@@ -1525,6 +1525,7 @@ int ast_call(struct ast_channel *chan, const char *addr, int timeout);
/*!
* \brief Indicates condition of channel
+ * \note Absolutely _NO_ channel locks should be held before calling this function.
* \note Indicate a condition such as AST_CONTROL_BUSY, AST_CONTROL_RINGING, or AST_CONTROL_CONGESTION on a channel
* \param chan channel to change the indication
* \param condition which condition to indicate on the channel
@@ -1534,6 +1535,7 @@ int ast_indicate(struct ast_channel *chan, int condition);
/*!
* \brief Indicates condition of channel, with payload
+ * \note Absolutely _NO_ channel locks should be held before calling this function.
* \note Indicate a condition such as AST_CONTROL_HOLD with payload being music on hold class
* \param chan channel to change the indication
* \param condition which condition to indicate on the channel
diff --git a/main/channel.c b/main/channel.c
index 35155bb6ba..f97855fb66 100644
--- a/main/channel.c
+++ b/main/channel.c
@@ -3765,6 +3765,7 @@ static struct ast_frame *__ast_read(struct ast_channel *chan, int dropaudio)
ast_party_connected_line_free(&connected);
break;
}
+ ast_channel_unlock(chan);
if (ast_channel_connected_line_sub(NULL, chan, &connected, 0) &&
ast_channel_connected_line_macro(NULL, chan, &connected, 1, 0)) {
ast_indicate_data(chan, AST_CONTROL_CONNECTED_LINE,
@@ -3772,6 +3773,7 @@ static struct ast_frame *__ast_read(struct ast_channel *chan, int dropaudio)
read_action_payload->payload_size);
}
ast_party_connected_line_free(&connected);
+ ast_channel_lock(chan);
break;
}
ast_frfree(f);
@@ -9361,10 +9363,16 @@ int ast_channel_connected_line_macro(struct ast_channel *autoservice_chan, struc
}
ast_channel_unlock(macro_chan);
- if (!(retval = ast_app_run_macro(autoservice_chan, macro_chan, macro, macro_args))) {
+ retval = ast_app_run_macro(autoservice_chan, macro_chan, macro, macro_args);
+ if (!retval) {
+ struct ast_party_connected_line saved_connected;
+
+ ast_party_connected_line_init(&saved_connected);
ast_channel_lock(macro_chan);
- ast_channel_update_connected_line(macro_chan, ast_channel_connected(macro_chan), NULL);
+ ast_party_connected_line_copy(&saved_connected, ast_channel_connected(macro_chan));
ast_channel_unlock(macro_chan);
+ ast_channel_update_connected_line(macro_chan, &saved_connected, NULL);
+ ast_party_connected_line_free(&saved_connected);
}
return retval;
@@ -9407,9 +9415,14 @@ int ast_channel_redirecting_macro(struct ast_channel *autoservice_chan, struct a
retval = ast_app_run_macro(autoservice_chan, macro_chan, macro, macro_args);
if (!retval) {
+ struct ast_party_redirecting saved_redirecting;
+
+ ast_party_redirecting_init(&saved_redirecting);
ast_channel_lock(macro_chan);
- ast_channel_update_redirecting(macro_chan, ast_channel_redirecting(macro_chan), NULL);
+ ast_party_redirecting_copy(&saved_redirecting, ast_channel_redirecting(macro_chan));
ast_channel_unlock(macro_chan);
+ ast_channel_update_redirecting(macro_chan, &saved_redirecting, NULL);
+ ast_party_redirecting_free(&saved_redirecting);
}
return retval;
@@ -9443,10 +9456,16 @@ int ast_channel_connected_line_sub(struct ast_channel *autoservice_chan, struct
}
ast_channel_unlock(sub_chan);
- if (!(retval = ast_app_run_sub(autoservice_chan, sub_chan, sub, sub_args))) {
+ retval = ast_app_run_sub(autoservice_chan, sub_chan, sub, sub_args);
+ if (!retval) {
+ struct ast_party_connected_line saved_connected;
+
+ ast_party_connected_line_init(&saved_connected);
ast_channel_lock(sub_chan);
- ast_channel_update_connected_line(sub_chan, ast_channel_connected(sub_chan), NULL);
+ ast_party_connected_line_copy(&saved_connected, ast_channel_connected(sub_chan));
ast_channel_unlock(sub_chan);
+ ast_channel_update_connected_line(sub_chan, &saved_connected, NULL);
+ ast_party_connected_line_free(&saved_connected);
}
return retval;
@@ -9482,9 +9501,14 @@ int ast_channel_redirecting_sub(struct ast_channel *autoservice_chan, struct ast
retval = ast_app_run_sub(autoservice_chan, sub_chan, sub, sub_args);
if (!retval) {
+ struct ast_party_redirecting saved_redirecting;
+
+ ast_party_redirecting_init(&saved_redirecting);
ast_channel_lock(sub_chan);
- ast_channel_update_redirecting(sub_chan, ast_channel_redirecting(sub_chan), NULL);
+ ast_party_redirecting_copy(&saved_redirecting, ast_channel_redirecting(sub_chan));
ast_channel_unlock(sub_chan);
+ ast_channel_update_redirecting(sub_chan, &saved_redirecting, NULL);
+ ast_party_redirecting_free(&saved_redirecting);
}
return retval;
--
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