From e078558038e2224b4473ea4bbe6f5ae304a0bebd Mon Sep 17 00:00:00 2001
From: Pirmin Walthert <infos@nappsoft.ch>
Date: Wed, 30 May 2018 08:12:30 +0200
Subject: [PATCH] bridge_channel.c: Fix Deadlock when using Local channels and
fax gateway
ast_indicate is invoked with the bridge locked. As ast_indicate locks the
other end of the bridge as well this can lead to a deadlock in some situations.
(Especially when a different thread does the same in the reverse order).
This patch calls ast_indicate after unlocking the bridge which fixes the
deadlock. Calling ast_indicate with these parameters without locking the
bridge should be safe as this is done at different places without a
bridge lock.
ASTERISK-27094 #close
Reported-by: David Brillert
Change-Id: I5f86c1e2ce75b9929a36ab589b18c450e62ea35f
---
main/bridge_channel.c | 7 ++++++-
1 file changed, 6 insertions(+), 1 deletion(-)
diff --git a/main/bridge_channel.c b/main/bridge_channel.c
index eb4b9ad0e8..7d7d26a6b8 100644
--- a/main/bridge_channel.c
+++ b/main/bridge_channel.c
@@ -2820,6 +2820,7 @@ static void bridge_channel_event_join_leave(struct ast_bridge_channel *bridge_ch
int bridge_channel_internal_join(struct ast_bridge_channel *bridge_channel)
{
int res = 0;
+ uint8_t indicate_src_change = 0;
struct ast_bridge_features *channel_features;
struct ast_channel *swap;
@@ -2889,7 +2890,7 @@ int bridge_channel_internal_join(struct ast_bridge_channel *bridge_channel)
*/
if (!(bridge_channel->bridge->technology->capabilities
& AST_BRIDGE_CAPABILITY_MULTIMIX)) {
- ast_indicate(bridge_channel->chan, AST_CONTROL_SRCCHANGE);
+ indicate_src_change = 1;
}
bridge_channel_impart_signal(bridge_channel->chan);
@@ -2899,6 +2900,10 @@ int bridge_channel_internal_join(struct ast_bridge_channel *bridge_channel)
ao2_t_cleanup(swap, "Bridge push with swap successful");
swap = NULL;
+ if (indicate_src_change) {
+ ast_indicate(bridge_channel->chan, AST_CONTROL_SRCCHANGE);
+ }
+
bridge_channel_event_join_leave(bridge_channel, AST_BRIDGE_HOOK_TYPE_JOIN);
while (bridge_channel->state == BRIDGE_CHANNEL_STATE_WAIT) {