chan_sip: Check sip_pvt pointer in ast_channel_get_t38_state(c)

Asterisk may crash when calling ast_channel_get_t38_state(c)
on a locked channel which is being hung up.

ASTERISK-25609 #close

Change-Id: Ifaa707c04b865a290ffab719bd2e5c48ff667c7b

diff --git a/channels/chan_sip.c b/channels/chan_sip.c
index c54224570539fd2d27eee6026aa2e021240cfc45..9bc15bbbcc076a9e1f236f516a518859cb6834e2 100644 (file)
--- a/channels/chan_sip.c
+++ b/channels/chan_sip.c
@@ -4752,6 +4752,11 @@ static int sip_queryoption(struct ast_channel *chan, int option, void *data, int
        struct sip_pvt *p = (struct sip_pvt *) ast_channel_tech_pvt(chan);
        char *cp;
 
+       if (!p) {
+               ast_debug(1, "Attempt to Ref a null pointer. Sip private structure is gone!\n");
+               return -1;
+       }
+
        sip_pvt_lock(p);
 
        switch (option) {