diff options
authorNeels Hofmeyr <nhofmeyr@sysmocom.de>2016-12-22 01:58:03 +0100
committerNeels Hofmeyr <nhofmeyr@sysmocom.de>2017-02-03 00:34:02 +0100
commit35706ddd80c248a9ef26e702c81e9865a7b8cf6d (patch)
parent26adfd099b8af407b038ae3bc9c70eced829a386 (diff)
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
1 files changed, 5 insertions, 0 deletions
diff --git a/openbsc/src/libmsc/gsm_04_08.c b/openbsc/src/libmsc/gsm_04_08.c
index 1e2575492..838071006 100644
--- a/openbsc/src/libmsc/gsm_04_08.c
+++ b/openbsc/src/libmsc/gsm_04_08.c
@@ -3605,6 +3605,11 @@ static int gsm0408_rcv_cc(struct gsm_subscriber_connection *conn, struct msgb *m
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);