Add additional checks for NULL pointers to fix several crashes reported.

ASTERISK-24304 #close
Reported by: dhanapathy sathya

git-svn-id: https://origsvn.digium.com/svn/asterisk/branches/11@426666 65c4cc65-6c06-0410-ace0-fbb531ad65f3

diff --git a/channels/chan_unistim.c b/channels/chan_unistim.c
index 173230e47f1be18e498bc55e3482a873c3c6f118..0366e690a6b01ad35872f2a89b7da7b5d8b44be8 100644 (file)
--- a/channels/chan_unistim.c
+++ b/channels/chan_unistim.c
@@ -2550,6 +2550,9 @@ static void *unistim_ss(void *data)
        struct unistimsession *s = l->parent->session;
        int res;
 
+       if (!s) {
+               return NULL;
+       }
        ast_verb(3, "Starting switch on '%s@%s-%d' to %s\n", l->name, l->parent->name, sub->softkey, s->device->phone_number);
        ast_channel_exten_set(chan, s->device->phone_number);
        ast_copy_string(s->device->redial_number, s->device->phone_number,
@@ -3306,6 +3309,9 @@ static void key_call(struct unistimsession *pte, char keycode)
        struct unistim_subchannel *sub = get_sub(pte->device, SUB_REAL);
        struct unistim_subchannel *sub_3way = get_sub(pte->device, SUB_THREEWAY);
 
+       if (!sub) {
+               return;
+       }
        if ((keycode >= KEY_0) && (keycode <= KEY_SHARP)) {
                if (keycode == KEY_SHARP) {
                        keycode = '#';
@@ -3319,7 +3325,7 @@ static void key_call(struct unistimsession *pte, char keycode)
        }
        switch (keycode) {
        case KEY_FUNC1:
-               if (ast_channel_state(sub->owner) == AST_STATE_UP) {
+               if (sub->owner && ast_channel_state(sub->owner) == AST_STATE_UP) {
                        if (sub_3way) {
                                close_call(pte);
                        }
@@ -3361,8 +3367,8 @@ static void key_call(struct unistimsession *pte, char keycode)
                                                         MUTE_OFF);
                break;
        case KEY_MUTE:
-               if (!sub || !sub->owner) {
-                       ast_log(LOG_WARNING, "Unable to find subchannel for music on hold\n");
+               if (!sub->owner) {
+                       ast_log(LOG_WARNING, "Unable to find channel for music on hold\n");
                        return;
                }
                if (!sub->moh) {