* [PATCH v2] ath10k: hold RCU lock when calling ieee80211_find_sta_by_ifaddr()
@ 2021-02-10 21:21 Shuah Khan
2021-02-11 18:26 ` Kalle Valo
0 siblings, 1 reply; 2+ messages in thread
From: Shuah Khan @ 2021-02-10 21:21 UTC (permalink / raw)
To: kvalo, davem, kuba
Cc: netdev, linux-wireless, linux-kernel, ath10k, Shuah Khan
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: Shuah Khan <skhan@linuxfoundation.org>
---
Changes since v1:
- v1 also included fix to ath10k_wmi_tlv_parse_peer_stats_info()
RCU wrn which was already fixed. v2 drops that and fixes just
ath10k_wmi_event_tdls_peer()
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 bfdd017f1405..d97b33f789e4 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);
}
--
2.27.0
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2021-02-10 21:21 [PATCH v2] ath10k: hold RCU lock when calling ieee80211_find_sta_by_ifaddr() Shuah Khan
2021-02-11 18:26 ` Kalle Valo
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