From cb0a0a9f2930bec6f1714544bbe33e9987a74e0c Mon Sep 17 00:00:00 2001
From: Richard Mudgett <rmudgett@digium.com>
Date: Fri, 30 Sep 2011 22:08:48 +0000
Subject: [PATCH] Merged revisions 338801 via svnmerge from
 https://origsvn.digium.com/svn/asterisk/branches/10

................
  r338801 | rmudgett | 2011-09-30 17:06:48 -0500 (Fri, 30 Sep 2011) | 19 lines

  Merged revisions 338800 via svnmerge from
  https://origsvn.digium.com/svn/asterisk/branches/1.8

  ........
    r338800 | rmudgett | 2011-09-30 17:05:10 -0500 (Fri, 30 Sep 2011) | 12 lines

    Fix segfault in analog_ss_thread() not checking ast_read() for NULL.

    NOTE: The problem was reported against v1.6.2.  It is unlikely to ever
    happen on v1.8 and above since chan_dahdi.c:analog_ss_thread() is unlikely
    to be used.  The version in sig_analog.c has largely replaced it.

    (closes issue ASTERISK-18648)
    Reported by: Stephan Bosch
    Patches:
          jira_asterisk_18648_v1.8.patch (license #5621) patch uploaded by rmudgett
    Tested by: Stephan Bosch
  ........
................


git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@338802 65c4cc65-6c06-0410-ace0-fbb531ad65f3
---
 channels/chan_dahdi.c | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/channels/chan_dahdi.c b/channels/chan_dahdi.c
index b26881c43e..11a7bda8b6 100644
--- a/channels/chan_dahdi.c
+++ b/channels/chan_dahdi.c
@@ -10695,9 +10695,14 @@ static void *analog_ss_thread(void *data)
 						ast_log(LOG_WARNING, "DTMFCID timed out waiting for ring. "
 							"Exiting simple switch\n");
 						ast_hangup(chan);
-						return NULL;
+						goto quit;
 					}
 					f = ast_read(chan);
+					if (!f) {
+						/* Hangup received waiting for DTMFCID. Exiting simple switch. */
+						ast_hangup(chan);
+						goto quit;
+					}
 					if (f->frametype == AST_FRAME_DTMF) {
 						dtmfbuf[k++] = f->subclass.integer;
 						ast_debug(1, "CID got digit '%c'\n", f->subclass.integer);