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.


git-svn-id: https://origsvn.digium.com/svn/asterisk/branches/1.8@359451 65c4cc65-6c06-0410-ace0-fbb531ad65f3

channels/chan_agent.c

@@ -966,9 +966,7 @@ static int agent_hangup(struct ast_channel *ast)
 		p->chan->_bridge = 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);
@@ -977,11 +975,9 @@ 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);
 	}
 

include/asterisk/channel.h

@@ -1631,6 +1631,7 @@ int ast_call(struct ast_channel *chan, 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
@@ -1640,6 +1641,7 @@ 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

main/channel.c

@@ -3976,12 +3976,14 @@ 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_macro(NULL, chan, &connected, 1, 0)) {
 						ast_indicate_data(chan, AST_CONTROL_CONNECTED_LINE,
 							read_action_payload->payload,
 							read_action_payload->payload_size);
 					}
 					ast_party_connected_line_free(&connected);
+					ast_channel_lock(chan);
 					break;
 				}
 				ast_frfree(f);
@@ -9368,10 +9370,16 @@ 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, &macro_chan->connected, NULL);
+		ast_party_connected_line_copy(&saved_connected, &macro_chan->connected);
 		ast_channel_unlock(macro_chan);
+		ast_channel_update_connected_line(macro_chan, &saved_connected, NULL);
+		ast_party_connected_line_free(&saved_connected);
 	}
 
 	return retval;
@@ -9409,9 +9417,14 @@ 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, &macro_chan->redirecting, NULL);
+		ast_party_redirecting_copy(&saved_redirecting, &macro_chan->redirecting);
 		ast_channel_unlock(macro_chan);
+		ast_channel_update_redirecting(macro_chan, &saved_redirecting, NULL);
+		ast_party_redirecting_free(&saved_redirecting);
 	}
 
 	return retval;