The function assumed an MM protocol discriminator without verifying it. --- openbsc/src/osmo-bsc/osmo_bsc_filter.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/openbsc/src/osmo-bsc/osmo_bsc_filter.c b/openbsc/src/osmo-bsc/osmo_bsc_filter.c index a71871f..14e0b71 100644 --- a/openbsc/src/osmo-bsc/osmo_bsc_filter.c +++ b/openbsc/src/osmo-bsc/osmo_bsc_filter.c @@ -336,6 +336,7 @@ int bsc_scan_msc_msg(struct gsm_subscriber_connection *conn, struct msgb *msg) struct gsm_network *net; struct gsm48_loc_area_id *lai; struct gsm48_hdr *gh; + uint8_t pdisc; uint8_t mtype; int length = msgb_l3len(msg); @@ -347,6 +348,10 @@ int bsc_scan_msc_msg(struct gsm_subscriber_connection *conn, struct msgb *msg) gh = (struct gsm48_hdr *) msgb_l3(msg); length -= (const char *)&gh->data[0] - (const char *)gh; + pdisc = gsm48_hdr_pdisc(gh); + if (pdisc != GSM48_PDISC_MM) + return 0; + mtype = gsm48_hdr_msg_type(gh); net = conn->bts->network; msc = conn->sccp_con->msc; -- 2.1.4