fixes crash in moh when cachertclasses flag is used

The result for moh_register was not verified to guarantee
the mohclass as added to the container.

(closes issue #16993)
Reported by: dmitri
Patches:
      res_musiconhold_rtclass2.patch uploaded by dmitri (license 1001)
      moh_crash2.diff uploaded by dvossel (license 671)
Tested by: dmitri

git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@269271 65c4cc65-6c06-0410-ace0-fbb531ad65f3

diff --git a/res/res_musiconhold.c b/res/res_musiconhold.c
index 4d2c9ec49ab6178dc9c4ea50414c2632124ac262..3f282275701b9cc819381ce38abfdf139bef4009 100644 (file)
--- a/res/res_musiconhold.c
+++ b/res/res_musiconhold.c
@@ -1373,7 +1373,10 @@ static int local_ast_moh_start(struct ast_channel *chan, const char *mclass, con
                                 * has a pointer to a freed mohclass, so any operations involving the mohclass container would result in reading
                                 * invalid memory.
                                 */
-                               moh_register(mohclass, 0, DONT_UNREF);
+                               if (moh_register(mohclass, 0, DONT_UNREF) == -1) {
+                                       mohclass = mohclass_unref(mohclass, "unreffing mohclass failed to register");
+                                       return -1;
+                               }
                        } else {
                                /* We don't register RT moh class, so let's init it manualy */