diff --git a/src/ap/hostapd.c b/src/ap/hostapd.c
index 6e4169ba9..dea552c1c 100644
--- a/src/ap/hostapd.c
+++ b/src/ap/hostapd.c
@@ -614,51 +614,145 @@ static int hostapd_das_nas_mismatch(struct hostapd_data *hapd,
 
 
 static struct sta_info * hostapd_das_find_sta(struct hostapd_data *hapd,
-					      struct radius_das_attrs *attr)
+					      struct radius_das_attrs *attr,
+					      int *multi)
 {
-	struct sta_info *sta = NULL;
+	struct sta_info *selected, *sta;
 	char buf[128];
+	int num_attr = 0;
+	int count;
 
-	if (attr->sta_addr)
+	*multi = 0;
+
+	for (sta = hapd->sta_list; sta; sta = sta->next)
+		sta->radius_das_match = 1;
+
+	if (attr->sta_addr) {
+		num_attr++;
 		sta = ap_get_sta(hapd, attr->sta_addr);
+		if (!sta) {
+			wpa_printf(MSG_DEBUG,
+				   "RADIUS DAS: No Calling-Station-Id match");
+			return NULL;
+		}
 
-	if (sta == NULL && attr->acct_session_id &&
-	    attr->acct_session_id_len == 17) {
+		selected = sta;
 		for (sta = hapd->sta_list; sta; sta = sta->next) {
+			if (sta != selected)
+				sta->radius_das_match = 0;
+		}
+		wpa_printf(MSG_DEBUG, "RADIUS DAS: Calling-Station-Id match");
+	}
+
+	if (attr->acct_session_id) {
+		num_attr++;
+		if (attr->acct_session_id_len != 17) {
+			wpa_printf(MSG_DEBUG,
+				   "RADIUS DAS: Acct-Session-Id cannot match");
+			return NULL;
+		}
+		count = 0;
+
+		for (sta = hapd->sta_list; sta; sta = sta->next) {
+			if (!sta->radius_das_match)
+				continue;
 			os_snprintf(buf, sizeof(buf), "%08X-%08X",
 				    sta->acct_session_id_hi,
 				    sta->acct_session_id_lo);
-			if (os_memcmp(attr->acct_session_id, buf, 17) == 0)
-				break;
+			if (os_memcmp(attr->acct_session_id, buf, 17) != 0)
+				sta->radius_das_match = 0;
+			else
+				count++;
 		}
+
+		if (count == 0) {
+			wpa_printf(MSG_DEBUG,
+				   "RADIUS DAS: No matches remaining after Acct-Session-Id check");
+			return NULL;
+		}
+		wpa_printf(MSG_DEBUG, "RADIUS DAS: Acct-Session-Id match");
 	}
 
-	if (sta == NULL && attr->cui) {
+	if (attr->cui) {
+		num_attr++;
+		count = 0;
+
 		for (sta = hapd->sta_list; sta; sta = sta->next) {
 			struct wpabuf *cui;
+
+			if (!sta->radius_das_match)
+				continue;
 			cui = ieee802_1x_get_radius_cui(sta->eapol_sm);
-			if (cui && wpabuf_len(cui) == attr->cui_len &&
+			if (!cui || wpabuf_len(cui) != attr->cui_len ||
 			    os_memcmp(wpabuf_head(cui), attr->cui,
-				      attr->cui_len) == 0)
-				break;
+				      attr->cui_len) != 0)
+				sta->radius_das_match = 0;
+			else
+				count++;
 		}
+
+		if (count == 0) {
+			wpa_printf(MSG_DEBUG,
+				   "RADIUS DAS: No matches remaining after Chargeable-User-Identity check");
+			return NULL;
+		}
+		wpa_printf(MSG_DEBUG,
+			   "RADIUS DAS: Chargeable-User-Identity match");
 	}
 
-	if (sta == NULL && attr->user_name) {
+	if (attr->user_name) {
+		num_attr++;
+		count = 0;
+
 		for (sta = hapd->sta_list; sta; sta = sta->next) {
 			u8 *identity;
 			size_t identity_len;
+
+			if (!sta->radius_das_match)
+				continue;
 			identity = ieee802_1x_get_identity(sta->eapol_sm,
 							   &identity_len);
-			if (identity &&
-			    identity_len == attr->user_name_len &&
+			if (!identity ||
+			    identity_len != attr->user_name_len ||
 			    os_memcmp(identity, attr->user_name, identity_len)
-			    == 0)
-				break;
+			    != 0)
+				sta->radius_das_match = 0;
+			else
+				count++;
+		}
+
+		if (count == 0) {
+			wpa_printf(MSG_DEBUG,
+				   "RADIUS DAS: No matches remaining after User-Name check");
+			return NULL;
+		}
+		wpa_printf(MSG_DEBUG,
+			   "RADIUS DAS: User-Name match");
+	}
+
+	if (num_attr == 0) {
+		/*
+		 * In theory, we could match all current associations, but it
+		 * seems safer to just reject requests that do not include any
+		 * session identification attributes.
+		 */
+		wpa_printf(MSG_DEBUG,
+			   "RADIUS DAS: No session identification attributes included");
+		return NULL;
+	}
+
+	selected = NULL;
+	for (sta = hapd->sta_list; sta; sta = sta->next) {
+		if (sta->radius_das_match) {
+			if (selected) {
+				*multi = 1;
+				return NULL;
+			}
+			selected = sta;
 		}
 	}
 
-	return sta;
+	return selected;
 }
 
 
@@ -667,14 +761,24 @@ hostapd_das_disconnect(void *ctx, struct radius_das_attrs *attr)
 {
 	struct hostapd_data *hapd = ctx;
 	struct sta_info *sta;
+	int multi;
 
 	if (hostapd_das_nas_mismatch(hapd, attr))
 		return RADIUS_DAS_NAS_MISMATCH;
 
-	sta = hostapd_das_find_sta(hapd, attr);
-	if (sta == NULL)
+	sta = hostapd_das_find_sta(hapd, attr, &multi);
+	if (sta == NULL) {
+		if (multi) {
+			wpa_printf(MSG_DEBUG,
+				   "RADIUS DAS: Multiple sessions match - not supported");
+			return RADIUS_DAS_MULTI_SESSION_MATCH;
+		}
+		wpa_printf(MSG_DEBUG, "RADIUS DAS: No matching session found");
 		return RADIUS_DAS_SESSION_NOT_FOUND;
+	}
 
+	wpa_printf(MSG_DEBUG, "RADIUS DAS: Found a matching session " MACSTR
+		   " - disconnecting", MAC2STR(sta->addr));
 	wpa_auth_pmksa_remove(hapd->wpa_auth, sta->addr);
 
 	hostapd_drv_sta_deauth(hapd, sta->addr,
diff --git a/src/ap/sta_info.h b/src/ap/sta_info.h
index 59d0e2915..57551ab17 100644
--- a/src/ap/sta_info.h
+++ b/src/ap/sta_info.h
@@ -85,6 +85,7 @@ struct sta_info {
 	unsigned int remediation:1;
 	unsigned int hs20_deauth_requested:1;
 	unsigned int session_timeout_set:1;
+	unsigned int radius_das_match:1;
 
 	u16 auth_alg;
 
diff --git a/src/radius/radius_das.c b/src/radius/radius_das.c
index 9655f4cea..7aa703cc6 100644
--- a/src/radius/radius_das.c
+++ b/src/radius/radius_das.c
@@ -147,6 +147,12 @@ static struct radius_msg * radius_das_disconnect(struct radius_das_data *das,
 			   "%s:%d", abuf, from_port);
 		error = 503;
 		break;
+	case RADIUS_DAS_MULTI_SESSION_MATCH:
+		wpa_printf(MSG_INFO,
+			   "DAS: Multiple sessions match for request from %s:%d",
+			   abuf, from_port);
+		error = 508;
+		break;
 	case RADIUS_DAS_SUCCESS:
 		error = 0;
 		break;
diff --git a/src/radius/radius_das.h b/src/radius/radius_das.h
index e3ed5408e..1d76c2662 100644
--- a/src/radius/radius_das.h
+++ b/src/radius/radius_das.h
@@ -14,7 +14,8 @@ struct radius_das_data;
 enum radius_das_res {
 	RADIUS_DAS_SUCCESS,
 	RADIUS_DAS_NAS_MISMATCH,
-	RADIUS_DAS_SESSION_NOT_FOUND
+	RADIUS_DAS_SESSION_NOT_FOUND,
+	RADIUS_DAS_MULTI_SESSION_MATCH,
 };
 
 struct radius_das_attrs {