Index: channels/chan_dahdi.c
===================================================================
--- channels/chan_dahdi.c	(revision 214702)
+++ channels/chan_dahdi.c	(working copy)
@@ -7876,6 +7876,7 @@
 	struct dahdi_pvt *tmp = NULL;
 	struct dahdi_pvt *prev = NULL;
 
+	ast_mutex_lock(&iflock);
 	tmp = iflist;
 	while (tmp) {
 		if (tmp->channel == channel) {
@@ -7888,6 +7889,7 @@
 		prev = tmp;
 		tmp = tmp->next;
 	}
+	ast_mutex_unlock(&iflock);
 	return RESULT_FAILURE;
 }