libmsc: fix NULL pointer dereference in trans_lcls_compose()

Change-Id: I96342de4cb3e0bc3d3cac7538d4517aa211e8a38
Fixes: CID#240768

1 files changed, 5 insertions, 5 deletions

diff --git a/src/libmsc/transaction.c b/src/libmsc/transaction.c
index 2108ab492..25c0e3c50 100644
--- a/src/libmsc/transaction.c
+++ b/src/libmsc/transaction.c
@@ -112,6 +112,11 @@ struct gsm_trans *trans_find_by_sm_rp_mr(const struct gsm_network *net,
 
 struct osmo_lcls *trans_lcls_compose(const struct gsm_trans *trans, bool use_lac)
 {
+	if (!trans) {
+		LOGP(DCC, LOGL_ERROR, "LCLS: unable to fill parameters for unallocated transaction\n");
+		return NULL;
+	}
+
 	if (!trans->net->a.sri->sccp)
 		return NULL;
 
@@ -119,11 +124,6 @@ struct osmo_lcls *trans_lcls_compose(const struct gsm_trans *trans, bool use_lac
 	struct osmo_lcls *lcls;
 	uint8_t w = osmo_ss7_pc_width(&ss7->cfg.pc_fmt);
 
-	if (!trans) {
-		LOGP(DCC, LOGL_ERROR, "LCLS: unable to fill parameters for unallocated transaction\n");
-		return NULL;
-	}
-
 	if (!trans->net->lcls_permitted) {
 		LOGP(DCC, LOGL_NOTICE, "LCLS disabled globally\n");
 		return NULL;