From: Russell Bryant <russell@russellbryant.com>
Date: Fri, 17 Aug 2007 21:01:43 +0000 (+0000)
Subject: Avoid a crash in the handling of DTMF based Caller ID.  It is valid for
X-Git-Tag: 1.4.12.1~230
X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=467ceebc82dba01b7cbd13ee483580be949758be;p=thirdparty%2Fasterisk.git

Avoid a crash in the handling of DTMF based Caller ID.  It is valid for
ast_read to return NULL in the case that the channel has been hung up.
(crash reported by anonymouz666 on IRC in #asterisk-dev)


git-svn-id: https://origsvn.digium.com/svn/asterisk/branches/1.4@79912 65c4cc65-6c06-0410-ace0-fbb531ad65f3
---

diff --git a/channels/chan_zap.c b/channels/chan_zap.c
index d20596dbd7..6c09670819 100644
--- a/channels/chan_zap.c
+++ b/channels/chan_zap.c
@@ -6111,6 +6111,8 @@ static void *ss_thread(void *data)
 						return NULL;
 					} 
 					f = ast_read(chan);
+					if (!f)
+						break;
 					if (f->frametype == AST_FRAME_DTMF) {
 						dtmfbuf[i++] = f->subclass;
 						ast_log(LOG_DEBUG, "CID got digit '%c'\n", f->subclass);