[PATCH 5.10 047/126] ath10k: hold RCU lock when calling ieee80211_find_sta_by_ifaddr()
From: Greg Kroah-Hartman
Date: Mon Apr 05 2021 - 05:10:03 EST
From: Shuah Khan <skhan@xxxxxxxxxxxxxxxxxxx>
[ Upstream commit 09078368d516918666a0122f2533dc73676d3d7e ]
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@xxxxxxxxxxxxxxxxxxx/
Signed-off-by: Shuah Khan <skhan@xxxxxxxxxxxxxxxxxxx>
Signed-off-by: Kalle Valo <kvalo@xxxxxxxxxxxxxx>
Link: https://lore.kernel.org/r/20210210212107.40373-1-skhan@xxxxxxxxxxxxxxxxxxx
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
drivers/net/wireless/ath/ath10k/wmi-tlv.c | 7 +++++--
1 file changed, 5 insertions(+), 2 deletions(-)
diff --git a/drivers/net/wireless/ath/ath10k/wmi-tlv.c b/drivers/net/wireless/ath/ath10k/wmi-tlv.c
index e6135795719a..e7072fc4f487 100644
--- a/drivers/net/wireless/ath/ath10k/wmi-tlv.c
+++ b/drivers/net/wireless/ath/ath10k/wmi-tlv.c
@@ -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);
}
--
2.30.1