gsm0408_rcv_cc: guard against NULL subscriber
Check conn->subscr against NULL.
gsm0408_rcv_cc() dereferences many conn members without checking presence: the
bts and lchan members may be expected to be NULL in the ongoing MSC split and
3G developments.
But the conn->subscr is initially NULL, so an MS sending a CC message before
something like a LU or CM Service Request will result in a segfault. Prevent
that.
Note: the upcoming VLR will be more restrictive on what messages are processed,
this is a "backport" to the situation on current master.
Change-Id: If067db7cc0dd3210d9eb1da15be6b637795a3ecf
diff --git a/openbsc/src/libmsc/gsm_04_08.c b/openbsc/src/libmsc/gsm_04_08.c
index 1e25754..8380710 100644
--- a/openbsc/src/libmsc/gsm_04_08.c
+++ b/openbsc/src/libmsc/gsm_04_08.c
@@ -3605,6 +3605,11 @@
return -EINVAL;
}
+ if (!conn->subscr) {
+ LOGP(DCC, LOGL_ERROR, "Invalid conn, no subscriber\n");
+ return -EINVAL;
+ }
+
/* Find transaction */
trans = trans_find_by_id(conn, GSM48_PDISC_CC, transaction_id);