From: Matthew Jordan <mjordan@digium.com>
Date: Thu, 28 Feb 2013 17:09:25 +0000 (+0000)
Subject: Prevent deadlock in chan_iax2 when attempting to set caller ID
X-Git-Tag: 1.8.22.0-rc1~25
X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=45b88e8f04cb2bfe5a76502dea0b6a1cad59af38;p=thirdparty%2Fasterisk.git

Prevent deadlock in chan_iax2 when attempting to set caller ID

A deadlock can occur in chan_iax2 when it attempts to set the caller ID, as it
already holds the iax2 private lock and improperly fails to obtain the channel
lock before calling ast_set_callerid. By not safely obtaining the channel lock,
a locking inversion can take place, causing a deadlock.

This patch solves this by calling the required deadlock avoidance functions
that obtain the channel lock before setting the caller ID.

Thanks to Pavel for fixing my syntax errors and testing this patch out.

(closes issue ASTERISK-21128)
Reported by: Pavel Troller
Tested by: Pavel Troller
patches:
  ASTERISK-21128-1.8.diff uploaded by mjordan (license 6283)
  ASTERISK-21128-modified-1.8.diff uploaded by Pavel Troller (license 6302)


git-svn-id: https://origsvn.digium.com/svn/asterisk/branches/1.8@382233 65c4cc65-6c06-0410-ace0-fbb531ad65f3
---

diff --git a/channels/chan_iax2.c b/channels/chan_iax2.c
index 5e615fd15c..d379cc4acc 100644
--- a/channels/chan_iax2.c
+++ b/channels/chan_iax2.c
@@ -11601,13 +11601,15 @@ immediatedial:
 			ast_string_field_set(iaxs[fr->callno], cid_name, connected.id.name.str);
 			iaxs[fr->callno]->calling_pres = ast_party_id_presentation(&connected.id);
 
-			if (iaxs[fr->callno]->owner) {
+			iax2_lock_owner(fr->callno);
+			if (iaxs[fr->callno] && iaxs[fr->callno]->owner) {
 				ast_set_callerid(iaxs[fr->callno]->owner,
 					S_COR(connected.id.number.valid, connected.id.number.str, ""),
 					S_COR(connected.id.name.valid, connected.id.name.str, ""),
 					NULL);
 				iaxs[fr->callno]->owner->caller.id.number.presentation = connected.id.number.presentation;
 				iaxs[fr->callno]->owner->caller.id.name.presentation = connected.id.name.presentation;
+				ast_channel_unlock(iaxs[fr->callno]->owner);
 			}
 		}
 		ast_party_connected_line_free(&connected);