Fix crash during CDR update.

The ast_cdr_setcid() and ast_cdr_update() were shown in ASTERISK-18836 to
be called by different threads for the same channel.  The channel driver
thread and the PBX thread running dialplan.

* Add lock protection around CDR API calls that access an ast_channel
pointer.

(closes issue ASTERISK-18836)
Reported by: gpluser

Review: https://reviewboard.asterisk.org/r/1628/
........

Merged revisions 348362 from http://svn.asterisk.org/svn/asterisk/branches/1.8
........

Merged revisions 348363 from http://svn.asterisk.org/svn/asterisk/branches/10


git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@348364 65c4cc65-6c06-0410-ace0-fbb531ad65f3

1 files changed, 12 insertions, 4 deletions

diff --git a/apps/app_followme.c b/apps/app_followme.c
index bab4d1ba3..9ee2e334e 100644
--- a/apps/app_followme.c
+++ b/apps/app_followme.c
@@ -492,10 +492,12 @@ static void clear_caller(struct findme_user *tmpuser)
 
 	if (tmpuser && tmpuser->ochan && tmpuser->state >= 0) {
 		outbound = tmpuser->ochan;
+		ast_channel_lock(outbound);
 		if (!outbound->cdr) {
 			outbound->cdr = ast_cdr_alloc();
-			if (outbound->cdr)
+			if (outbound->cdr) {
 				ast_cdr_init(outbound->cdr, outbound);
+			}
 		}
 		if (outbound->cdr) {
 			char tmp[256];
@@ -506,11 +508,15 @@ static void clear_caller(struct findme_user *tmpuser)
 			ast_cdr_start(outbound->cdr);
 			ast_cdr_end(outbound->cdr);
 			/* If the cause wasn't handled properly */
-			if (ast_cdr_disposition(outbound->cdr, outbound->hangupcause))
+			if (ast_cdr_disposition(outbound->cdr, outbound->hangupcause)) {
 				ast_cdr_failed(outbound->cdr);
-		} else
+			}
+		} else {
 			ast_log(LOG_WARNING, "Unable to create Call Detail Record\n");
-		ast_hangup(tmpuser->ochan);
+		}
+		ast_channel_unlock(outbound);
+		ast_hangup(outbound);
+		tmpuser->ochan = NULL;
 	}
 }
 
@@ -890,6 +896,7 @@ static void findmeexec(struct fm_args *tpargs)
 					AST_LIST_INSERT_TAIL(findme_user_list, tmpuser, entry);
 				} else {
 					ast_verb(3, "couldn't reach at this number.\n");
+					ast_channel_lock(outbound);
 					if (!outbound->cdr) {
 						outbound->cdr = ast_cdr_alloc();
 					}
@@ -909,6 +916,7 @@ static void findmeexec(struct fm_args *tpargs)
 					} else {
 						ast_log(LOG_ERROR, "Unable to create Call Detail Record\n");
 					}
+					ast_channel_unlock(outbound);
 					ast_hangup(outbound);
 					ast_free(tmpuser);
 				}