From: Russell Bryant <russell@russellbryant.com>
Date: Mon, 5 Nov 2007 21:35:51 +0000 (+0000)
Subject: Merged revisions 88768 via svnmerge from
X-Git-Tag: 1.6.0-beta1~3^2~996
X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=44bf97386533fe5b83bed7f1fae5d473682ddb3f;p=thirdparty%2Fasterisk.git

Merged revisions 88768 via svnmerge from
https://origsvn.digium.com/svn/asterisk/branches/1.4

........
r88768 | russell | 2007-11-05 15:33:56 -0600 (Mon, 05 Nov 2007) | 8 lines

When traversing the list of channel variables here in transmit_invite(), the
asterisk channel must be locked, as this data may change at any time.

(I have seen numerous reports of crashes related to the handling of channel
variables.  There are a couple of issues on the bug tracker related to it,
but it has also been noted on IRC and mailing lists.  So, I am finding and
fixing some places where channel variables are handled improperly.)

........


git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@88769 65c4cc65-6c06-0410-ace0-fbb531ad65f3
---

diff --git a/channels/chan_sip.c b/channels/chan_sip.c
index 80c8f72e3b..1aff65fc86 100644
--- a/channels/chan_sip.c
+++ b/channels/chan_sip.c
@@ -7752,8 +7752,12 @@ static int transmit_invite(struct sip_pvt *p, int sipmethod, int sdp, int init)
 	add_header(&req, "Allow", ALLOWED_METHODS);
 	add_header(&req, "Supported", SUPPORTED_EXTENSIONS);
 	if (p->options && p->options->addsipheaders && p->owner) {
-		struct ast_channel *ast = p->owner; /* The owner channel */
-		struct varshead *headp = &ast->varshead;
+		struct ast_channel *chan = p->owner; /* The owner channel */
+		struct varshead *headp;
+	
+		ast_channel_lock(chan);
+
+		headp = &chan->varshead;
 
 		if (!headp)
 			ast_log(LOG_WARNING,"No Headp for the channel...ooops!\n");
@@ -7784,6 +7788,8 @@ static int transmit_invite(struct sip_pvt *p, int sipmethod, int sdp, int init)
 				}
 			}
 		}
+
+		ast_channel_unlock(chan);
 	}
 	if (sdp) {
 		if (p->udptl && p->t38.state == T38_LOCAL_DIRECT) {