From: Scott Griepentrog <sgriepentrog@digium.com>
Date: Wed, 26 Feb 2014 19:00:07 +0000 (+0000)
Subject: pjsip: avoid edge case potential crash in answer()
X-Git-Tag: 12.2.0-rc1~125
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=33d60bed468ead3fb325ac196dfb89485eda0dd5;p=thirdparty%2Fasterisk.git

pjsip: avoid edge case potential crash in answer()

When accidentally compiling against a wrong version of
pjsip headers with a different pjsip_inv_session size,
the invite_tsx structure could be null in the answer()
function.  This led to a crash because it attempted to
send the session response with an uninitialized packet
pointer.  This patch presets packet to null and adds a
diagnostic log message to explain why the call fails.

Review: https://reviewboard.asterisk.org/r/3267/



git-svn-id: https://origsvn.digium.com/svn/asterisk/branches/12@408970 65c4cc65-6c06-0410-ace0-fbb531ad65f3
---

diff --git a/channels/chan_pjsip.c b/channels/chan_pjsip.c
index af0496a900..e324b3347c 100644
--- a/channels/chan_pjsip.c
+++ b/channels/chan_pjsip.c
@@ -438,12 +438,15 @@ static struct ast_channel *chan_pjsip_new(struct ast_sip_session *session, int s
 static int answer(void *data)
 {
 	pj_status_t status = PJ_SUCCESS;
-	pjsip_tx_data *packet;
+	pjsip_tx_data *packet = NULL;
 	struct ast_sip_session *session = data;
 
 	pjsip_dlg_inc_lock(session->inv_session->dlg);
 	if (session->inv_session->invite_tsx) {
 		status = pjsip_inv_answer(session->inv_session, 200, NULL, NULL, &packet);
+	} else {
+		ast_log(LOG_ERROR,"Cannot answer '%s' because there is no associated SIP transaction\n",
+			ast_channel_name(session->channel));
 	}
 	pjsip_dlg_dec_lock(session->inv_session->dlg);