Prevent a crash in chan_local due to a potential NULL pointer dereference

Move the check for if both channels on a local_pvt have generators to below
where p->chan is checked for NULLity (NULLness?). This prevents a crash from
occurring if p->chan is NULL.

(closes issue #14189)
Reported by: sascha
Patches:
      14189.patch uploaded by putnopvut (license 60)
Tested by: sascha

git-svn-id: https://origsvn.digium.com/svn/asterisk/branches/1.4@169210 65c4cc65-6c06-0410-ace0-fbb531ad65f3

diff --git a/channels/chan_local.c b/channels/chan_local.c
index b2e3c72b8cb8719b086ebbff212e602d2a9eb5d3..9f3dd1d77cfcf884563f3aaf1cda32a9c0773208 100644 (file)
--- a/channels/chan_local.c
+++ b/channels/chan_local.c
@@ -168,10 +168,6 @@ static int local_queue_frame(struct local_pvt *p, int isoutbound, struct ast_fra
        /* Recalculate outbound channel */
        other = isoutbound ? p->owner : p->chan;
 
-       /* do not queue frame if generator is on both local channels */
-       if (us && us->generator && other->generator)
-               return 0;
-
        /* Set glare detection */
        ast_set_flag(p, LOCAL_GLARE_DETECT);
        if (ast_test_flag(p, LOCAL_CANCEL_QUEUE)) {
@@ -186,6 +182,10 @@ static int local_queue_frame(struct local_pvt *p, int isoutbound, struct ast_fra
                return 0;
        }
 
+       /* do not queue frame if generator is on both local channels */
+       if (us && us->generator && other->generator)
+               return 0;
+
        /* Ensure that we have both channels locked */
        while (other && ast_channel_trylock(other)) {
                ast_mutex_unlock(&p->lock);