From: Sean Bright <sean@malleable.com>
Date: Thu, 19 Apr 2012 16:04:21 +0000 (+0000)
Subject: Prevent a crash in ExternalIVR when the 'S' command is sent first.
X-Git-Tag: 10.5.0-rc1~48
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=9fcf8338c56ee2cd9bccb49441d422282dc74a36;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
........

Merged revisions 362586 from http://svn.asterisk.org/svn/asterisk/branches/1.8


git-svn-id: https://origsvn.digium.com/svn/asterisk/branches/10@362587 65c4cc65-6c06-0410-ace0-fbb531ad65f3
---

diff --git a/apps/app_externalivr.c b/apps/app_externalivr.c
index 03ef884c87..6cbfbd1377 100644
--- a/apps/app_externalivr.c
+++ b/apps/app_externalivr.c
@@ -683,13 +683,14 @@ 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);
@@ -768,9 +769,10 @@ 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);