Commit 09078368 authored by Shuah Khan's avatar Shuah Khan Committed by Kalle Valo
Browse files

ath10k: hold RCU lock when calling ieee80211_find_sta_by_ifaddr() 

ieee80211_find_sta_by_ifaddr() must be called under the RCU lock and
the resulting pointer is only valid under RCU lock as well.

Fix ath10k_wmi_tlv_op_pull_peer_stats_info() to hold RCU lock before it
calls ieee80211_find_sta_by_ifaddr() and release it when the resulting
pointer is no longer needed.

This problem was found while reviewing code to debug RCU warn from
ath10k_wmi_tlv_parse_peer_stats_info().

Link: https://lore.kernel.org/linux-wireless/7230c9e5-2632-b77e-c4f9-10eca557a5bb@linuxfoundation.org/


Signed-off-by: default avatarShuah Khan <skhan@linuxfoundation.org>
Signed-off-by: default avatarKalle Valo <kvalo@codeaurora.org>
Link: https://lore.kernel.org/r/20210210212107.40373-1-skhan@linuxfoundation.org
parent 83bae265

drivers/net/wireless/ath/ath10k/wmi-tlv.c

+5 −2
Original line number Diff line number Diff line
@@ -576,13 +576,13 @@ static void ath10k_wmi_event_tdls_peer(struct ath10k *ar, struct sk_buff *skb) 
	case WMI_TDLS_TEARDOWN_REASON_TX:

	case WMI_TDLS_TEARDOWN_REASON_RSSI:

	case WMI_TDLS_TEARDOWN_REASON_PTR_TIMEOUT:

		rcu_read_lock();

		station = ieee80211_find_sta_by_ifaddr(ar->hw,

						       ev->peer_macaddr.addr,

						       NULL);

		if (!station) {

			ath10k_warn(ar, "did not find station from tdls peer event");

			kfree(tb);

			return;

			goto exit;

		}

		arvif = ath10k_get_arvif(ar, __le32_to_cpu(ev->vdev_id));

		ieee80211_tdls_oper_request(
@@ -593,6 +593,9 @@ static void ath10k_wmi_event_tdls_peer(struct ath10k *ar, struct sk_buff *skb) 
					);

		break;

	}



exit:

	rcu_read_unlock();

	kfree(tb);

}