Guido Casati
6512a7a9ca
During re-establishment, new KgNB* is derived, requiring new UP keys (KUPint, KUPenc) to be sent to CU-UP. When do_drb_integrity = true, CU-UP needs the updated integrity keys to verify DRB PDUs. Without this update, CU-UP uses old keys while the UE uses new keys, causing integrity failures. The fix ensures security info is always sent during re-establishment, which is critical for DRB integrity.