As commented in the code, the GSM_SECURITY_AUTH_FAILED path is never invoked by the gsm48_secure_channel() function as it is today.

Note that the upcoming Iu auth will probably add a GSM_SECURITY_AUTH_FAILED status. In that case, sending a LU Reject immediately may be desirable, but arguably a bit of timeout could make life harder for auth attackers.

The code removed by this patch doesn't send out a LU Reject ever, since a call to release_loc_updating_req() only releases the connection. To reject, a call to gsm0408_loc_upd_rej() would be necessary, as seen in loc_upd_rej_cb().

And finally, if _gsm0408_authorize_sec_cb() doesn't do anything about anything, the same loc_upd_rej_cb() will be run by a timeout and send a LU Reject properly (as commented in the code). --- openbsc/src/libmsc/gsm_04_08.c | 17 +++++++++++++---- 1 file changed, 13 insertions(+), 4 deletions(-)

diff --git a/openbsc/src/libmsc/gsm_04_08.c b/openbsc/src/libmsc/gsm_04_08.c index d9d7390..47f3fa7 100644 --- a/openbsc/src/libmsc/gsm_04_08.c +++ b/openbsc/src/libmsc/gsm_04_08.c @@ -340,10 +340,6 @@ static int _gsm0408_authorize_sec_cb(unsigned int hooknum, unsigned int event, int rc = 0;

switch (event) { - case GSM_SECURITY_AUTH_FAILED: - release_loc_updating_req(conn, 1); - break; - case GSM_SECURITY_ALREADY: LOGP(DMM, LOGL_ERROR, "We don't expect LOCATION " "UPDATING after CM SERVICE REQUEST\n"); @@ -354,6 +350,19 @@ static int _gsm0408_authorize_sec_cb(unsigned int hooknum, unsigned int event, rc = finish_lu(conn); break;

+ case GSM_SECURITY_AUTH_FAILED: + /* + * gsm48_secure_channel() will pass only + * GSM_SECURITY_NOAVAIL in case of failure. If future + * code should add a GSM_SECURITY_AUTH_FAILED status in + * this code path, letting the Location Update time out + * will do all necessary error messaging and logging, + * see loc_upd_rej_cb(). + */ + LOGP(DMM, LOGL_ERROR, + "Authorization failed for subscriber %s\n", + subscr_name(conn->subscr)); + /* fall through */ default: rc = -EINVAL; };