diff --git a/hostapd/ap_list.c b/hostapd/ap_list.c
index 1cdf0a24d..ec6c2c06c 100644
--- a/hostapd/ap_list.c
+++ b/hostapd/ap_list.c
@@ -55,7 +55,7 @@ static int ap_list_beacon_olbc(struct hostapd_iface *iface, struct ap_info *ap)
 }
 
 
-struct ap_info * ap_get_ap(struct hostapd_iface *iface, u8 *ap)
+struct ap_info * ap_get_ap(struct hostapd_iface *iface, const u8 *ap)
 {
 	struct ap_info *s;
 
@@ -195,7 +195,7 @@ int ap_ap_for_each(struct hostapd_iface *iface,
 }
 
 
-static struct ap_info * ap_ap_add(struct hostapd_iface *iface, u8 *addr)
+static struct ap_info * ap_ap_add(struct hostapd_iface *iface, const u8 *addr)
 {
 	struct ap_info *ap;
 
@@ -221,7 +221,7 @@ static struct ap_info * ap_ap_add(struct hostapd_iface *iface, u8 *addr)
 
 
 void ap_list_process_beacon(struct hostapd_iface *iface,
-			    struct ieee80211_mgmt *mgmt,
+			    const struct ieee80211_mgmt *mgmt,
 			    struct ieee802_11_elems *elems,
 			    struct hostapd_frame_info *fi)
 {
diff --git a/hostapd/ap_list.h b/hostapd/ap_list.h
index 22181c71b..f49f58b54 100644
--- a/hostapd/ap_list.h
+++ b/hostapd/ap_list.h
@@ -54,11 +54,11 @@ struct ap_info {
 struct ieee802_11_elems;
 struct hostapd_frame_info;
 
-struct ap_info * ap_get_ap(struct hostapd_iface *iface, u8 *sta);
+struct ap_info * ap_get_ap(struct hostapd_iface *iface, const u8 *sta);
 int ap_ap_for_each(struct hostapd_iface *iface,
 		   int (*func)(struct ap_info *s, void *data), void *data);
 void ap_list_process_beacon(struct hostapd_iface *iface,
-			    struct ieee80211_mgmt *mgmt,
+			    const struct ieee80211_mgmt *mgmt,
 			    struct ieee802_11_elems *elems,
 			    struct hostapd_frame_info *fi);
 #ifdef NEED_AP_MLME
diff --git a/hostapd/beacon.c b/hostapd/beacon.c
index 420433e08..1f653238c 100644
--- a/hostapd/beacon.c
+++ b/hostapd/beacon.c
@@ -191,13 +191,14 @@ static u8 * hostapd_eid_wpa(struct hostapd_data *hapd, u8 *eid, size_t len,
 }
 
 
-void handle_probe_req(struct hostapd_data *hapd, struct ieee80211_mgmt *mgmt,
-		      size_t len)
+void handle_probe_req(struct hostapd_data *hapd,
+		      const struct ieee80211_mgmt *mgmt, size_t len)
 {
 	struct ieee80211_mgmt *resp;
 	struct ieee802_11_elems elems;
 	char *ssid;
-	u8 *pos, *epos, *ie;
+	u8 *pos, *epos;
+	const u8 *ie;
 	size_t ssid_len, ie_len;
 	struct sta_info *sta = NULL;
 
diff --git a/hostapd/beacon.h b/hostapd/beacon.h
index ca80ac0f0..c1510e194 100644
--- a/hostapd/beacon.h
+++ b/hostapd/beacon.h
@@ -18,8 +18,8 @@
 
 struct ieee80211_mgmt;
 
-void handle_probe_req(struct hostapd_data *hapd, struct ieee80211_mgmt *mgmt,
-		      size_t len);
+void handle_probe_req(struct hostapd_data *hapd,
+		      const struct ieee80211_mgmt *mgmt, size_t len);
 #ifdef NEED_AP_MLME
 void ieee802_11_set_beacon(struct hostapd_data *hapd);
 void ieee802_11_set_beacons(struct hostapd_iface *iface);
diff --git a/hostapd/drv_callbacks.c b/hostapd/drv_callbacks.c
index 55c753990..29c86c85c 100644
--- a/hostapd/drv_callbacks.c
+++ b/hostapd/drv_callbacks.c
@@ -351,14 +351,14 @@ static void hostapd_rx_from_unknown_sta(struct hostapd_data *hapd,
 }
 
 
-static void hostapd_mgmt_rx(struct hostapd_data *hapd, u8 *buf,
+static void hostapd_mgmt_rx(struct hostapd_data *hapd, const u8 *buf,
 			    size_t len, struct hostapd_frame_info *fi)
 {
 	struct hostapd_iface *iface = hapd->iface;
-	struct ieee80211_hdr *hdr;
+	const struct ieee80211_hdr *hdr;
 	const u8 *bssid;
 
-	hdr = (struct ieee80211_hdr *) buf;
+	hdr = (const struct ieee80211_hdr *) buf;
 	bssid = get_hdr_bssid(hdr, len);
 	if (bssid == NULL)
 		return;
diff --git a/hostapd/ieee802_11.c b/hostapd/ieee802_11.c
index bf50abbce..8d4fe3923 100644
--- a/hostapd/ieee802_11.c
+++ b/hostapd/ieee802_11.c
@@ -196,7 +196,8 @@ void ieee802_11_print_ssid(char *buf, const u8 *ssid, u8 len)
  * @addr: Address of the destination STA
  * @reason: Reason code for Deauthentication
  */
-void ieee802_11_send_deauth(struct hostapd_data *hapd, u8 *addr, u16 reason)
+void ieee802_11_send_deauth(struct hostapd_data *hapd, const u8 *addr,
+			    u16 reason)
 {
 	struct ieee80211_mgmt mgmt;
 
@@ -217,7 +218,8 @@ void ieee802_11_send_deauth(struct hostapd_data *hapd, u8 *addr, u16 reason)
 
 
 static u16 auth_shared_key(struct hostapd_data *hapd, struct sta_info *sta,
-			   u16 auth_transaction, u8 *challenge, int iswep)
+			   u16 auth_transaction, const u8 *challenge,
+			   int iswep)
 {
 	hostapd_logger(hapd, sta->addr, HOSTAPD_MODULE_IEEE80211,
 		       HOSTAPD_LEVEL_DEBUG,
@@ -339,15 +341,15 @@ static void handle_auth_ft_finish(void *ctx, const u8 *dst, const u8 *bssid,
 #endif /* CONFIG_IEEE80211R */
 
 
-static void handle_auth(struct hostapd_data *hapd, struct ieee80211_mgmt *mgmt,
-			size_t len)
+static void handle_auth(struct hostapd_data *hapd,
+			const struct ieee80211_mgmt *mgmt, size_t len)
 {
 	u16 auth_alg, auth_transaction, status_code;
 	u16 resp = WLAN_STATUS_SUCCESS;
 	struct sta_info *sta = NULL;
 	int res;
 	u16 fc;
-	u8 *challenge = NULL;
+	const u8 *challenge = NULL;
 	u32 session_timeout, acct_interim_interval;
 	int vlan_id = 0;
 	u8 resp_ies[2 + WLAN_AUTH_CHALLENGE_LEN];
@@ -635,7 +637,7 @@ static u16 copy_supp_rates(struct hostapd_data *hapd, struct sta_info *sta,
 
 
 static u16 check_assoc_ies(struct hostapd_data *hapd, struct sta_info *sta,
-			   u8 *ies, size_t ies_len, int reassoc)
+			   const u8 *ies, size_t ies_len, int reassoc)
 {
 	struct ieee802_11_elems elems;
 	u16 resp;
@@ -821,7 +823,7 @@ static void send_deauth(struct hostapd_data *hapd, const u8 *addr,
 
 
 static void send_assoc_resp(struct hostapd_data *hapd, struct sta_info *sta,
-			    u16 status_code, int reassoc, u8 *ies,
+			    u16 status_code, int reassoc, const u8 *ies,
 			    size_t ies_len)
 {
 	int send_len;
@@ -882,11 +884,12 @@ static void send_assoc_resp(struct hostapd_data *hapd, struct sta_info *sta,
 
 
 static void handle_assoc(struct hostapd_data *hapd,
-			 struct ieee80211_mgmt *mgmt, size_t len, int reassoc)
+			 const struct ieee80211_mgmt *mgmt, size_t len,
+			 int reassoc)
 {
 	u16 capab_info, listen_interval;
 	u16 resp = WLAN_STATUS_SUCCESS;
-	u8 *pos;
+	const u8 *pos;
 	int left, i;
 	struct sta_info *sta;
 
@@ -1139,7 +1142,7 @@ static void handle_deauth(struct hostapd_data *hapd,
 
 
 static void handle_beacon(struct hostapd_data *hapd,
-			  struct ieee80211_mgmt *mgmt, size_t len,
+			  const struct ieee80211_mgmt *mgmt, size_t len,
 			  struct hostapd_frame_info *fi)
 {
 	struct ieee802_11_elems elems;
@@ -1190,10 +1193,11 @@ void ieee802_11_send_sa_query_req(struct hostapd_data *hapd,
 
 
 static void hostapd_sa_query_action(struct hostapd_data *hapd,
-				    struct ieee80211_mgmt *mgmt, size_t len)
+				    const struct ieee80211_mgmt *mgmt,
+				    size_t len)
 {
 	struct sta_info *sta;
-	u8 *end;
+	const u8 *end;
 	int i;
 
 	end = mgmt->u.action.u.sa_query_resp.trans_id +
@@ -1255,7 +1259,7 @@ static int robust_action_frame(u8 category)
 
 
 static void handle_action(struct hostapd_data *hapd,
-			  struct ieee80211_mgmt *mgmt, size_t len)
+			  const struct ieee80211_mgmt *mgmt, size_t len)
 {
 	struct sta_info *sta;
 
@@ -1315,6 +1319,8 @@ static void handle_action(struct hostapd_data *hapd,
 		       mgmt->u.action.category);
 	if (!(mgmt->da[0] & 0x01) && !(mgmt->u.action.category & 0x80) &&
 	    !(mgmt->sa[0] & 0x01)) {
+		struct ieee80211_mgmt *resp;
+
 		/*
 		 * IEEE 802.11-REVma/D9.0 - 7.3.1.11
 		 * Return the Action frame to the source without change
@@ -1322,12 +1328,17 @@ static void handle_action(struct hostapd_data *hapd,
 		 */
 		wpa_printf(MSG_DEBUG, "IEEE 802.11: Return unknown Action "
 			   "frame back to sender");
-		os_memcpy(mgmt->da, mgmt->sa, ETH_ALEN);
-		os_memcpy(mgmt->sa, hapd->own_addr, ETH_ALEN);
-		os_memcpy(mgmt->bssid, hapd->own_addr, ETH_ALEN);
-		mgmt->u.action.category |= 0x80;
+		resp = os_malloc(len);
+		if (resp == NULL)
+			return;
+		os_memcpy(resp, mgmt, len);
+		os_memcpy(resp->da, resp->sa, ETH_ALEN);
+		os_memcpy(resp->sa, hapd->own_addr, ETH_ALEN);
+		os_memcpy(resp->bssid, hapd->own_addr, ETH_ALEN);
+		resp->u.action.category |= 0x80;
 
-		hostapd_send_mgmt_frame(hapd, mgmt, len);
+		hostapd_send_mgmt_frame(hapd, resp, len);
+		os_free(resp);
 	}
 }
 
@@ -1345,7 +1356,7 @@ static void handle_action(struct hostapd_data *hapd,
  * addition, it can be called to re-inserted pending frames (e.g., when using
  * external RADIUS server as an MAC ACL).
  */
-void ieee802_11_mgmt(struct hostapd_data *hapd, u8 *buf, size_t len,
+void ieee802_11_mgmt(struct hostapd_data *hapd, const u8 *buf, size_t len,
 		     struct hostapd_frame_info *fi)
 {
 	struct ieee80211_mgmt *mgmt;
diff --git a/hostapd/ieee802_11.h b/hostapd/ieee802_11.h
index 93a2a50a4..95c99b2d3 100644
--- a/hostapd/ieee802_11.h
+++ b/hostapd/ieee802_11.h
@@ -23,8 +23,9 @@ struct hostapd_data;
 struct sta_info;
 struct hostapd_frame_info;
 
-void ieee802_11_send_deauth(struct hostapd_data *hapd, u8 *addr, u16 reason);
-void ieee802_11_mgmt(struct hostapd_data *hapd, u8 *buf, size_t len,
+void ieee802_11_send_deauth(struct hostapd_data *hapd, const u8 *addr,
+			    u16 reason);
+void ieee802_11_mgmt(struct hostapd_data *hapd, const u8 *buf, size_t len,
 		     struct hostapd_frame_info *fi);
 void ieee802_11_mgmt_cb(struct hostapd_data *hapd, const u8 *buf, size_t len,
 			u16 stype, int ok);
diff --git a/hostapd/wme.c b/hostapd/wme.c
index 8e17a4170..f539e9896 100644
--- a/hostapd/wme.c
+++ b/hostapd/wme.c
@@ -223,13 +223,13 @@ int wmm_process_tspec(struct wmm_tspec_element *tspec)
 
 
 static void wmm_addts_req(struct hostapd_data *hapd,
-			  struct ieee80211_mgmt *mgmt,
+			  const struct ieee80211_mgmt *mgmt,
 			  struct wmm_tspec_element *tspec, size_t len)
 {
-	u8 *end = ((u8 *) mgmt) + len;
+	const u8 *end = ((const u8 *) mgmt) + len;
 	int res;
 
-	if ((u8 *) (tspec + 1) > end) {
+	if ((const u8 *) (tspec + 1) > end) {
 		wpa_printf(MSG_DEBUG, "WMM: TSPEC overflow in ADDTS Request");
 		return;
 	}
@@ -247,12 +247,12 @@ static void wmm_addts_req(struct hostapd_data *hapd,
 }
 
 
-void hostapd_wmm_action(struct hostapd_data *hapd, struct ieee80211_mgmt *mgmt,
-			size_t len)
+void hostapd_wmm_action(struct hostapd_data *hapd,
+			const struct ieee80211_mgmt *mgmt, size_t len)
 {
 	int action_code;
 	int left = len - IEEE80211_HDRLEN - 4;
-	u8 *pos = ((u8 *) mgmt) + IEEE80211_HDRLEN + 4;
+	const u8 *pos = ((const u8 *) mgmt) + IEEE80211_HDRLEN + 4;
 	struct ieee802_11_elems elems;
 	struct sta_info *sta = ap_get_sta(hapd, mgmt->sa);
 
diff --git a/hostapd/wme.h b/hostapd/wme.h
index 8fd2b7c00..fbaf8adc5 100644
--- a/hostapd/wme.h
+++ b/hostapd/wme.h
@@ -21,8 +21,8 @@ struct ieee80211_mgmt;
 u8 * hostapd_eid_wmm(struct hostapd_data *hapd, u8 *eid);
 int hostapd_eid_wmm_valid(struct hostapd_data *hapd, const u8 *eid,
 			  size_t len);
-void hostapd_wmm_action(struct hostapd_data *hapd, struct ieee80211_mgmt *mgmt,
-			size_t len);
+void hostapd_wmm_action(struct hostapd_data *hapd,
+			const struct ieee80211_mgmt *mgmt, size_t len);
 int wmm_process_tspec(struct wmm_tspec_element *tspec);
 
 #endif /* WME_H */
diff --git a/src/drivers/driver.h b/src/drivers/driver.h
index c6dbcb286..7fa4ed2a0 100644
--- a/src/drivers/driver.h
+++ b/src/drivers/driver.h
@@ -1942,7 +1942,7 @@ union wpa_event_data {
 	 * struct rx_mgmt - Data for EVENT_RX_MGMT events
 	 */
 	struct rx_mgmt {
-		u8 *frame;
+		const u8 *frame;
 		size_t frame_len;
 		struct hostapd_frame_info *fi;
 	} rx_mgmt;
diff --git a/wpa_supplicant/ap.c b/wpa_supplicant/ap.c
index 2e0882a57..9dbe719a3 100644
--- a/wpa_supplicant/ap.c
+++ b/wpa_supplicant/ap.c
@@ -501,7 +501,7 @@ void ap_rx_from_unknown_sta(void *ctx, const struct ieee80211_hdr *hdr,
 }
 
 
-void ap_mgmt_rx(void *ctx, u8 *buf, size_t len,
+void ap_mgmt_rx(void *ctx, const u8 *buf, size_t len,
 		struct hostapd_frame_info *fi)
 {
 #ifdef NEED_AP_MLME
diff --git a/wpa_supplicant/ap.h b/wpa_supplicant/ap.h
index 487de45af..a1975d789 100644
--- a/wpa_supplicant/ap.h
+++ b/wpa_supplicant/ap.h
@@ -36,7 +36,7 @@ void ap_tx_status(void *ctx, const u8 *addr,
 		  const u8 *buf, size_t len, int ack);
 void ap_rx_from_unknown_sta(void *ctx, const struct ieee80211_hdr *hdr,
 			    size_t len);
-void ap_mgmt_rx(void *ctx, u8 *buf, size_t len,
+void ap_mgmt_rx(void *ctx, const u8 *buf, size_t len,
 		struct hostapd_frame_info *fi);
 void ap_mgmt_tx_cb(void *ctx, const u8 *buf, size_t len, u16 stype, int ok);