iwlwifi: mvm: add notification size checks

We shouldn't trust the firmware with the sizes (or contents) of notifications, accessing too much data could cause page faults if the data doesn't fit into the allocated space. This applies more on older NICs where multiple notifications can be in a single RX buffer. Add a general framework for checking a minimum size of any notification in the RX handlers and use it for most. Some RX handlers were already checking and I've moved the checks, some more complex checks I left and made them _NO_SIZE for the RX handlers. Signed-off-by: Johannes Berg <johannes.berg@intel.com> Signed-off-by: Luca Coelho <luciano.coelho@intel.com> Link: https://lore.kernel.org/r/iwlwifi.20210117130510.3e155d5e5f90.I2121fa4ac7cd7eb98970d84b793796646afa3eed@changeid Signed-off-by: Luca Coelho <luciano.coelho@intel.com>
2021-01-17 13:10:28 +02:00 · 2021-01-17 13:10:28 +02:00 · afc857bc2a
parent 4832bb371c
commit afc857bc2a
6 changed files with 113 additions and 70 deletions
--- a/drivers/net/wireless/intel/iwlwifi/fw/api/debug.h
+++ b/drivers/net/wireless/intel/iwlwifi/fw/api/debug.h
@ -185,6 +185,21 @@ struct iwl_shared_mem_cfg {
 	__le32 rxfifo2_control_size;
 } __packed; /* SHARED_MEM_ALLOC_API_S_VER_4 */

+/**
+ * struct iwl_mfuart_load_notif_v1 - mfuart image version & status
+ * ( MFUART_LOAD_NOTIFICATION = 0xb1 )
+ * @installed_ver: installed image version
+ * @external_ver: external image version
+ * @status: MFUART loading status
+ * @duration: MFUART loading time
+*/
+struct iwl_mfuart_load_notif_v1 {
+	__le32 installed_ver;
+	__le32 external_ver;
+	__le32 status;
+	__le32 duration;
+} __packed; /* MFU_LOADER_NTFY_API_S_VER_1 */
+
 /**
 * struct iwl_mfuart_load_notif - mfuart image version & status
 * ( MFUART_LOAD_NOTIFICATION = 0xb1 )
--- a/drivers/net/wireless/intel/iwlwifi/mvm/mac-ctxt.c
+++ b/drivers/net/wireless/intel/iwlwifi/mvm/mac-ctxt.c
@ -1289,6 +1289,7 @@ void iwl_mvm_rx_beacon_notif(struct iwl_mvm *mvm,
 			     struct iwl_rx_cmd_buffer *rxb)
 {
 	struct iwl_rx_packet *pkt = rxb_addr(rxb);
+	unsigned int pkt_len = iwl_rx_packet_payload_len(pkt);
 	struct iwl_extended_beacon_notif *beacon = (void *)pkt->data;
 	struct iwl_extended_beacon_notif_v5 *beacon_v5 = (void *)pkt->data;
 	struct ieee80211_vif *csa_vif;
@ -1304,6 +1305,9 @@ void iwl_mvm_rx_beacon_notif(struct iwl_mvm *mvm,
 		struct iwl_mvm_tx_resp *beacon_notify_hdr =
 			&beacon_v5->beacon_notify_hdr;

+		if (unlikely(pkt_len < sizeof(*beacon_v5)))
+			return;
+
 		mvm->ibss_manager = beacon_v5->ibss_mgr_status != 0;
 		agg_status = iwl_mvm_get_agg_status(mvm, beacon_notify_hdr);
 		status = le16_to_cpu(agg_status->status) & TX_STATUS_MSK;
@ -1314,6 +1318,9 @@ void iwl_mvm_rx_beacon_notif(struct iwl_mvm *mvm,
 			     mvm->ap_last_beacon_gp2,
 			     le32_to_cpu(beacon_notify_hdr->initial_rate));
 	} else {
+		if (unlikely(pkt_len < sizeof(*beacon)))
+			return;
+
 		mvm->ibss_manager = beacon->ibss_mgr_status != 0;
 		status = le32_to_cpu(beacon->status) & TX_STATUS_MSK;
 		IWL_DEBUG_RX(mvm,
@ -1419,12 +1426,13 @@ void iwl_mvm_rx_stored_beacon_notif(struct iwl_mvm *mvm,
 				    struct iwl_rx_cmd_buffer *rxb)
 {
 	struct iwl_rx_packet *pkt = rxb_addr(rxb);
+	unsigned int pkt_len = iwl_rx_packet_payload_len(pkt);
 	struct iwl_stored_beacon_notif *sb = (void *)pkt->data;
 	struct ieee80211_rx_status rx_status;
 	struct sk_buff *skb;
 	u32 size = le32_to_cpu(sb->byte_count);

-	if (size == 0)
+	if (size == 0 || pkt_len < struct_size(sb, data, size))
 		return;

 	skb = alloc_skb(size, GFP_ATOMIC);
@ -1460,14 +1468,10 @@ void iwl_mvm_probe_resp_data_notif(struct iwl_mvm *mvm,
 	struct iwl_rx_packet *pkt = rxb_addr(rxb);
 	struct iwl_probe_resp_data_notif *notif = (void *)pkt->data;
 	struct iwl_probe_resp_data *old_data, *new_data;
-	int len = iwl_rx_packet_payload_len(pkt);
 	u32 id = le32_to_cpu(notif->mac_id);
 	struct ieee80211_vif *vif;
 	struct iwl_mvm_vif *mvmvif;

-	if (WARN_ON_ONCE(len < sizeof(*notif)))
-		return;
-
 	IWL_DEBUG_INFO(mvm, "Probe response data notif: noa %d, csa %d\n",
 		       notif->noa_active, notif->csa_counter);

@ -1514,12 +1518,8 @@ void iwl_mvm_channel_switch_noa_notif(struct iwl_mvm *mvm,
 	struct iwl_channel_switch_noa_notif *notif = (void *)pkt->data;
 	struct ieee80211_vif *csa_vif, *vif;
 	struct iwl_mvm_vif *mvmvif;
-	int len = iwl_rx_packet_payload_len(pkt);
 	u32 id_n_color, csa_id, mac_id;

-	if (WARN_ON_ONCE(len < sizeof(*notif)))
-		return;
-
 	id_n_color = le32_to_cpu(notif->id_and_color);
 	mac_id = id_n_color & FW_CTXT_ID_MSK;

--- a/drivers/net/wireless/intel/iwlwifi/mvm/ops.c
+++ b/drivers/net/wireless/intel/iwlwifi/mvm/ops.c
@ -169,15 +169,21 @@ enum iwl_rx_handler_context {
 * @fn: the function is called when notification is received
 */
 struct iwl_rx_handlers {
-	u16 cmd_id;
+	u16 cmd_id, min_size;
 	enum iwl_rx_handler_context context;
 	void (*fn)(struct iwl_mvm *mvm, struct iwl_rx_cmd_buffer *rxb);
 };

-#define RX_HANDLER(_cmd_id, _fn, _context)	\
-	{ .cmd_id = _cmd_id, .fn = _fn, .context = _context }
-#define RX_HANDLER_GRP(_grp, _cmd, _fn, _context)	\
-	{ .cmd_id = WIDE_ID(_grp, _cmd), .fn = _fn, .context = _context }
+#define RX_HANDLER_NO_SIZE(_cmd_id, _fn, _context)		\
+	{ .cmd_id = _cmd_id, .fn = _fn, .context = _context, }
+#define RX_HANDLER_GRP_NO_SIZE(_grp, _cmd, _fn, _context)	\
+	{ .cmd_id = WIDE_ID(_grp, _cmd), .fn = _fn, .context = _context, }
+#define RX_HANDLER(_cmd_id, _fn, _context, _struct)		\
+	{ .cmd_id = _cmd_id, .fn = _fn,				\
+	  .context = _context, .min_size = sizeof(_struct), }
+#define RX_HANDLER_GRP(_grp, _cmd, _fn, _context, _struct)	\
+	{ .cmd_id = WIDE_ID(_grp, _cmd), .fn = _fn,		\
+	  .context = _context, .min_size = sizeof(_struct), }

 /*
 * Handlers for fw notifications
@ -187,85 +193,104 @@ struct iwl_rx_handlers {
 * The handler can be one from three contexts, see &iwl_rx_handler_context
 */
 static const struct iwl_rx_handlers iwl_mvm_rx_handlers[] = {
-	RX_HANDLER(TX_CMD, iwl_mvm_rx_tx_cmd, RX_HANDLER_SYNC),
-	RX_HANDLER(BA_NOTIF, iwl_mvm_rx_ba_notif, RX_HANDLER_SYNC),
+	RX_HANDLER(TX_CMD, iwl_mvm_rx_tx_cmd, RX_HANDLER_SYNC,
+		   struct iwl_mvm_tx_resp),
+	RX_HANDLER(BA_NOTIF, iwl_mvm_rx_ba_notif, RX_HANDLER_SYNC,
+		   struct iwl_mvm_ba_notif),

 	RX_HANDLER_GRP(DATA_PATH_GROUP, TLC_MNG_UPDATE_NOTIF,
-		       iwl_mvm_tlc_update_notif, RX_HANDLER_SYNC),
+		       iwl_mvm_tlc_update_notif, RX_HANDLER_SYNC,
+		       struct iwl_tlc_update_notif),

 	RX_HANDLER(BT_PROFILE_NOTIFICATION, iwl_mvm_rx_bt_coex_notif,
-		   RX_HANDLER_ASYNC_LOCKED),
-	RX_HANDLER(BEACON_NOTIFICATION, iwl_mvm_rx_beacon_notif,
-		   RX_HANDLER_ASYNC_LOCKED),
-	RX_HANDLER(STATISTICS_NOTIFICATION, iwl_mvm_rx_statistics,
-		   RX_HANDLER_ASYNC_LOCKED),
+		   RX_HANDLER_ASYNC_LOCKED, struct iwl_bt_coex_profile_notif),
+	RX_HANDLER_NO_SIZE(BEACON_NOTIFICATION, iwl_mvm_rx_beacon_notif,
+			   RX_HANDLER_ASYNC_LOCKED),
+	RX_HANDLER_NO_SIZE(STATISTICS_NOTIFICATION, iwl_mvm_rx_statistics,
+			   RX_HANDLER_ASYNC_LOCKED),

 	RX_HANDLER(BA_WINDOW_STATUS_NOTIFICATION_ID,
-		   iwl_mvm_window_status_notif, RX_HANDLER_SYNC),
+		   iwl_mvm_window_status_notif, RX_HANDLER_SYNC,
+		   struct iwl_ba_window_status_notif),

 	RX_HANDLER(TIME_EVENT_NOTIFICATION, iwl_mvm_rx_time_event_notif,
-		   RX_HANDLER_SYNC),
+		   RX_HANDLER_SYNC, struct iwl_time_event_notif),
 	RX_HANDLER_GRP(MAC_CONF_GROUP, SESSION_PROTECTION_NOTIF,
-		       iwl_mvm_rx_session_protect_notif, RX_HANDLER_SYNC),
+		       iwl_mvm_rx_session_protect_notif, RX_HANDLER_SYNC,
+		       struct iwl_mvm_session_prot_notif),
 	RX_HANDLER(MCC_CHUB_UPDATE_CMD, iwl_mvm_rx_chub_update_mcc,
-		   RX_HANDLER_ASYNC_LOCKED),
+		   RX_HANDLER_ASYNC_LOCKED, struct iwl_mcc_chub_notif),

-	RX_HANDLER(EOSP_NOTIFICATION, iwl_mvm_rx_eosp_notif, RX_HANDLER_SYNC),
+	RX_HANDLER(EOSP_NOTIFICATION, iwl_mvm_rx_eosp_notif, RX_HANDLER_SYNC,
+		   struct iwl_mvm_eosp_notification),

 	RX_HANDLER(SCAN_ITERATION_COMPLETE,
-		   iwl_mvm_rx_lmac_scan_iter_complete_notif, RX_HANDLER_SYNC),
+		   iwl_mvm_rx_lmac_scan_iter_complete_notif, RX_HANDLER_SYNC,
+		   struct iwl_lmac_scan_complete_notif),
 	RX_HANDLER(SCAN_OFFLOAD_COMPLETE,
 		   iwl_mvm_rx_lmac_scan_complete_notif,
-		   RX_HANDLER_ASYNC_LOCKED),
-	RX_HANDLER(MATCH_FOUND_NOTIFICATION, iwl_mvm_rx_scan_match_found,
-		   RX_HANDLER_SYNC),
+		   RX_HANDLER_ASYNC_LOCKED, struct iwl_periodic_scan_complete),
+	RX_HANDLER_NO_SIZE(MATCH_FOUND_NOTIFICATION,
+			   iwl_mvm_rx_scan_match_found,
+			   RX_HANDLER_SYNC),
 	RX_HANDLER(SCAN_COMPLETE_UMAC, iwl_mvm_rx_umac_scan_complete_notif,
-		   RX_HANDLER_ASYNC_LOCKED),
+		   RX_HANDLER_ASYNC_LOCKED, struct iwl_umac_scan_complete),
 	RX_HANDLER(SCAN_ITERATION_COMPLETE_UMAC,
-		   iwl_mvm_rx_umac_scan_iter_complete_notif, RX_HANDLER_SYNC),
+		   iwl_mvm_rx_umac_scan_iter_complete_notif, RX_HANDLER_SYNC,
+		   struct iwl_umac_scan_iter_complete_notif),

 	RX_HANDLER(CARD_STATE_NOTIFICATION, iwl_mvm_rx_card_state_notif,
-		   RX_HANDLER_SYNC),
+		   RX_HANDLER_SYNC, struct iwl_card_state_notif),

 	RX_HANDLER(MISSED_BEACONS_NOTIFICATION, iwl_mvm_rx_missed_beacons_notif,
-		   RX_HANDLER_SYNC),
+		   RX_HANDLER_SYNC, struct iwl_missed_beacons_notif),

-	RX_HANDLER(REPLY_ERROR, iwl_mvm_rx_fw_error, RX_HANDLER_SYNC),
+	RX_HANDLER(REPLY_ERROR, iwl_mvm_rx_fw_error, RX_HANDLER_SYNC,
+		   struct iwl_error_resp),
 	RX_HANDLER(PSM_UAPSD_AP_MISBEHAVING_NOTIFICATION,
-		   iwl_mvm_power_uapsd_misbehaving_ap_notif, RX_HANDLER_SYNC),
-	RX_HANDLER(DTS_MEASUREMENT_NOTIFICATION, iwl_mvm_temp_notif,
-		   RX_HANDLER_ASYNC_LOCKED),
-	RX_HANDLER_GRP(PHY_OPS_GROUP, DTS_MEASUREMENT_NOTIF_WIDE,
-		       iwl_mvm_temp_notif, RX_HANDLER_ASYNC_UNLOCKED),
+		   iwl_mvm_power_uapsd_misbehaving_ap_notif, RX_HANDLER_SYNC,
+		   struct iwl_uapsd_misbehaving_ap_notif),
+	RX_HANDLER_NO_SIZE(DTS_MEASUREMENT_NOTIFICATION, iwl_mvm_temp_notif,
+			   RX_HANDLER_ASYNC_LOCKED),
+	RX_HANDLER_GRP_NO_SIZE(PHY_OPS_GROUP, DTS_MEASUREMENT_NOTIF_WIDE,
+			       iwl_mvm_temp_notif, RX_HANDLER_ASYNC_UNLOCKED),
 	RX_HANDLER_GRP(PHY_OPS_GROUP, CT_KILL_NOTIFICATION,
-		       iwl_mvm_ct_kill_notif, RX_HANDLER_SYNC),
+		       iwl_mvm_ct_kill_notif, RX_HANDLER_SYNC,
+		       struct ct_kill_notif),

 	RX_HANDLER(TDLS_CHANNEL_SWITCH_NOTIFICATION, iwl_mvm_rx_tdls_notif,
-		   RX_HANDLER_ASYNC_LOCKED),
+		   RX_HANDLER_ASYNC_LOCKED,
+		   struct iwl_tdls_channel_switch_notif),
 	RX_HANDLER(MFUART_LOAD_NOTIFICATION, iwl_mvm_rx_mfuart_notif,
-		   RX_HANDLER_SYNC),
+		   RX_HANDLER_SYNC, struct iwl_mfuart_load_notif_v1),
 	RX_HANDLER_GRP(LOCATION_GROUP, TOF_RESPONDER_STATS,
-		       iwl_mvm_ftm_responder_stats, RX_HANDLER_ASYNC_LOCKED),
+		       iwl_mvm_ftm_responder_stats, RX_HANDLER_ASYNC_LOCKED,
+		       struct iwl_ftm_responder_stats),

-	RX_HANDLER_GRP(LOCATION_GROUP, TOF_RANGE_RESPONSE_NOTIF,
-		       iwl_mvm_ftm_range_resp, RX_HANDLER_ASYNC_LOCKED),
-	RX_HANDLER_GRP(LOCATION_GROUP, TOF_LC_NOTIF,
-		       iwl_mvm_ftm_lc_notif, RX_HANDLER_ASYNC_LOCKED),
+	RX_HANDLER_GRP_NO_SIZE(LOCATION_GROUP, TOF_RANGE_RESPONSE_NOTIF,
+			       iwl_mvm_ftm_range_resp, RX_HANDLER_ASYNC_LOCKED),
+	RX_HANDLER_GRP_NO_SIZE(LOCATION_GROUP, TOF_LC_NOTIF,
+			       iwl_mvm_ftm_lc_notif, RX_HANDLER_ASYNC_LOCKED),

 	RX_HANDLER_GRP(DEBUG_GROUP, MFU_ASSERT_DUMP_NTF,
-		       iwl_mvm_mfu_assert_dump_notif, RX_HANDLER_SYNC),
+		       iwl_mvm_mfu_assert_dump_notif, RX_HANDLER_SYNC,
+		       struct iwl_mfu_assert_dump_notif),
 	RX_HANDLER_GRP(PROT_OFFLOAD_GROUP, STORED_BEACON_NTF,
-		       iwl_mvm_rx_stored_beacon_notif, RX_HANDLER_SYNC),
+		       iwl_mvm_rx_stored_beacon_notif, RX_HANDLER_SYNC,
+		       struct iwl_stored_beacon_notif),
 	RX_HANDLER_GRP(DATA_PATH_GROUP, MU_GROUP_MGMT_NOTIF,
-		       iwl_mvm_mu_mimo_grp_notif, RX_HANDLER_SYNC),
+		       iwl_mvm_mu_mimo_grp_notif, RX_HANDLER_SYNC,
+		       struct iwl_mu_group_mgmt_notif),
 	RX_HANDLER_GRP(DATA_PATH_GROUP, STA_PM_NOTIF,
-		       iwl_mvm_sta_pm_notif, RX_HANDLER_SYNC),
+		       iwl_mvm_sta_pm_notif, RX_HANDLER_SYNC,
+		       struct iwl_mvm_pm_state_notification),
 	RX_HANDLER_GRP(MAC_CONF_GROUP, PROBE_RESPONSE_DATA_NOTIF,
 		       iwl_mvm_probe_resp_data_notif,
-		       RX_HANDLER_ASYNC_LOCKED),
+		       RX_HANDLER_ASYNC_LOCKED,
+		       struct iwl_probe_resp_data_notif),
 	RX_HANDLER_GRP(MAC_CONF_GROUP, CHANNEL_SWITCH_NOA_NOTIF,
 		       iwl_mvm_channel_switch_noa_notif,
-		       RX_HANDLER_SYNC),
+		       RX_HANDLER_SYNC, struct iwl_channel_switch_noa_notif),
 };
 #undef RX_HANDLER
 #undef RX_HANDLER_GRP
@ -960,6 +985,7 @@ static void iwl_mvm_rx_common(struct iwl_mvm *mvm,
 			      struct iwl_rx_cmd_buffer *rxb,
 			      struct iwl_rx_packet *pkt)
 {
+	unsigned int pkt_len = iwl_rx_packet_payload_len(pkt);
 	int i;
 	union iwl_dbg_tlv_tp_data tp_data = { .fw_pkt = pkt };

@ -981,6 +1007,9 @@ static void iwl_mvm_rx_common(struct iwl_mvm *mvm,
 		if (rx_h->cmd_id != WIDE_ID(pkt->hdr.group_id, pkt->hdr.cmd))
 			continue;

+		if (unlikely(pkt_len < rx_h->min_size))
+			return;
+
 		if (rx_h->context == RX_HANDLER_SYNC) {
 			rx_h->fn(mvm, rxb);
 			return;
--- a/drivers/net/wireless/intel/iwlwifi/mvm/rx.c
+++ b/drivers/net/wireless/intel/iwlwifi/mvm/rx.c
@ -874,12 +874,11 @@ void iwl_mvm_window_status_notif(struct iwl_mvm *mvm,
 	struct iwl_rx_packet *pkt = rxb_addr(rxb);
 	struct iwl_ba_window_status_notif *notif = (void *)pkt->data;
 	int i;
-	u32 pkt_len = iwl_rx_packet_payload_len(pkt);

-	if (WARN_ONCE(pkt_len != sizeof(*notif),
-		      "Received window status notification of wrong size (%u)\n",
-		      pkt_len))
-		return;
+	BUILD_BUG_ON(ARRAY_SIZE(notif->ra_tid) != BA_WINDOW_STREAMS_MAX);
+	BUILD_BUG_ON(ARRAY_SIZE(notif->mpdu_rx_count) != BA_WINDOW_STREAMS_MAX);
+	BUILD_BUG_ON(ARRAY_SIZE(notif->bitmap) != BA_WINDOW_STREAMS_MAX);
+	BUILD_BUG_ON(ARRAY_SIZE(notif->start_seq_num) != BA_WINDOW_STREAMS_MAX);

 	rcu_read_lock();
 	for (i = 0; i < BA_WINDOW_STREAMS_MAX; i++) {
--- a/drivers/net/wireless/intel/iwlwifi/mvm/tt.c
+++ b/drivers/net/wireless/intel/iwlwifi/mvm/tt.c
@ -156,12 +156,6 @@ void iwl_mvm_ct_kill_notif(struct iwl_mvm *mvm, struct iwl_rx_cmd_buffer *rxb)
 {
 	struct iwl_rx_packet *pkt = rxb_addr(rxb);
 	struct ct_kill_notif *notif;
-	int len = iwl_rx_packet_payload_len(pkt);
-
-	if (WARN_ON_ONCE(len != sizeof(*notif))) {
-		IWL_ERR(mvm, "Invalid CT_KILL_NOTIFICATION\n");
-		return;
-	}

 	notif = (struct ct_kill_notif *)pkt->data;
 	IWL_DEBUG_TEMP(mvm, "CT Kill notification temperature = %d\n",
--- a/drivers/net/wireless/intel/iwlwifi/mvm/tx.c
+++ b/drivers/net/wireless/intel/iwlwifi/mvm/tx.c
@ -1840,6 +1840,7 @@ out:
 void iwl_mvm_rx_ba_notif(struct iwl_mvm *mvm, struct iwl_rx_cmd_buffer *rxb)
 {
 	struct iwl_rx_packet *pkt = rxb_addr(rxb);
+	unsigned int pkt_len = iwl_rx_packet_payload_len(pkt);
 	int sta_id, tid, txq, index;
 	struct ieee80211_tx_info ba_info = {};
 	struct iwl_mvm_ba_notif *ba_notif;
@ -1852,8 +1853,12 @@ void iwl_mvm_rx_ba_notif(struct iwl_mvm *mvm, struct iwl_rx_cmd_buffer *rxb)
 		struct iwl_mvm_compressed_ba_notif *ba_res =
 			(void *)pkt->data;
 		u8 lq_color = TX_RES_RATE_TABLE_COL_GET(ba_res->tlc_rate_info);
+		u16 tfd_cnt;
 		int i;

+		if (unlikely(sizeof(*ba_res) > pkt_len))
+			return;
+
 		sta_id = ba_res->sta_id;
 		ba_info.status.ampdu_ack_len = (u8)le16_to_cpu(ba_res->done);
 		ba_info.status.ampdu_len = (u8)le16_to_cpu(ba_res->txed);
@ -1862,8 +1867,9 @@ void iwl_mvm_rx_ba_notif(struct iwl_mvm *mvm, struct iwl_rx_cmd_buffer *rxb)
 		ba_info.status.status_driver_data[0] =
 			(void *)(uintptr_t)ba_res->reduced_txp;

-		if (!le16_to_cpu(ba_res->tfd_cnt))
-			goto out;
+		tfd_cnt = le16_to_cpu(ba_res->tfd_cnt);
+		if (!tfd_cnt || struct_size(ba_res, tfd, tfd_cnt) > pkt_len)
+			return;

 		rcu_read_lock();

@ -1878,7 +1884,7 @@ void iwl_mvm_rx_ba_notif(struct iwl_mvm *mvm, struct iwl_rx_cmd_buffer *rxb)
 		 */

 		/* Free per TID */
-		for (i = 0; i < le16_to_cpu(ba_res->tfd_cnt); i++) {
+		for (i = 0; i < tfd_cnt; i++) {
 			struct iwl_mvm_compressed_ba_tfd *ba_tfd =
 				&ba_res->tfd[i];

@ -1900,7 +1906,7 @@ void iwl_mvm_rx_ba_notif(struct iwl_mvm *mvm, struct iwl_rx_cmd_buffer *rxb)
 			iwl_mvm_tx_airtime(mvm, mvmsta,
 					   le32_to_cpu(ba_res->wireless_time));
 		rcu_read_unlock();
-out:
+
 		IWL_DEBUG_TX_REPLY(mvm,
 				   "BA_NOTIFICATION Received from sta_id = %d, flags %x, sent:%d, acked:%d\n",
 				   sta_id, le32_to_cpu(ba_res->flags),