From: Sean Bright <sean@malleable.com>
Date: Thu, 19 Apr 2012 15:53:56 +0000 (+0000)
Subject: Prevent a crash in ExternalIVR when the 'S' command is sent first.
X-Git-Tag: 1.8.13.0-rc1~42
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=c2447e0cc8124a5260c7456816f743f09d86cfd6;p=thirdparty%2Fasterisk.git

Prevent a crash in ExternalIVR when the 'S' command is sent first.

If the first command sent from an ExternalIVR client is an 'S' command, we were
blindly removing the first element from the play list and deferencing it, even
if it was NULL.  This corrects that and also locks appropriately in one place.

(issue ASTERISK-17889)
Reported by: Chris Maciejewski


git-svn-id: https://origsvn.digium.com/svn/asterisk/branches/1.8@362586 65c4cc65-6c06-0410-ace0-fbb531ad65f3
---

diff --git a/apps/app_externalivr.c b/apps/app_externalivr.c
index b91fc5025e..b05baed7bc 100644
--- a/apps/app_externalivr.c
+++ b/apps/app_externalivr.c
@@ -682,13 +682,14 @@ static int eivr_comm(struct ast_channel *chan, struct ivr_localuser *u,
  			if (f->frametype == AST_FRAME_DTMF) {
  				send_eivr_event(eivr_events, f->subclass.integer, NULL, chan);
  				if (u->option_autoclear) {
+  					AST_LIST_LOCK(&u->playlist);
   					if (!u->abort_current_sound && !u->playing_silence) {
 						/* send interrupted file as T data */
- 						entry = AST_LIST_REMOVE_HEAD(&u->playlist, list);
- 						send_eivr_event(eivr_events, 'T', entry->filename, chan);
-						ast_free(entry);
+ 						if ((entry = AST_LIST_REMOVE_HEAD(&u->playlist, list))) {
+	 						send_eivr_event(eivr_events, 'T', entry->filename, chan);
+							ast_free(entry);
+						}
 					}
-  					AST_LIST_LOCK(&u->playlist);
   					while ((entry = AST_LIST_REMOVE_HEAD(&u->playlist, list))) {
  						send_eivr_event(eivr_events, 'D', entry->filename, chan);
   						ast_free(entry);
@@ -767,9 +768,10 @@ static int eivr_comm(struct ast_channel *chan, struct ivr_localuser *u,
  					AST_LIST_LOCK(&u->playlist);
 	 				if (!u->abort_current_sound && !u->playing_silence) {
 						/* send interrupted file as T data */
- 						entry = AST_LIST_REMOVE_HEAD(&u->playlist, list);
- 						send_eivr_event(eivr_events, 'T', entry->filename, chan);
-						ast_free(entry);
+ 						if ((entry = AST_LIST_REMOVE_HEAD(&u->playlist, list))) {
+	 						send_eivr_event(eivr_events, 'T', entry->filename, chan);
+							ast_free(entry);
+						}
 					}
  					while ((entry = AST_LIST_REMOVE_HEAD(&u->playlist, list))) {
  						send_eivr_event(eivr_events, 'D', entry->filename, chan);