| Date | Mon, 5 Apr 2021 17:34:52 +0200 | From | Pavel Machek <> | Subject | Re: [PATCH 5.10 047/126] ath10k: hold RCU lock when calling ieee80211_find_sta_by_ifaddr() |
| |
Hi!
> 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.
It does that. But is also does the unlock even if it did not take the lock:
> +++ 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); > }
The switch only takes the lock in 3 branches, but it is released unconditionally at the end.
Something like this?
Best regards, Pavel
Signed-off-by: Pavel Machek (CIP) <pavel@denx.de>
diff --git a/drivers/net/wireless/ath/ath10k/wmi-tlv.c b/drivers/net/wireless/ath/ath10k/wmi-tlv.c index e7072fc4f487..e03ff56d938b 100644 --- a/drivers/net/wireless/ath/ath10k/wmi-tlv.c +++ b/drivers/net/wireless/ath/ath10k/wmi-tlv.c @@ -582,20 +582,19 @@ static void ath10k_wmi_event_tdls_peer(struct ath10k *ar, struct sk_buff *skb) NULL); if (!station) { ath10k_warn(ar, "did not find station from tdls peer event"); - goto exit; - } - arvif = ath10k_get_arvif(ar, __le32_to_cpu(ev->vdev_id)); - ieee80211_tdls_oper_request( + } else { + arvif = ath10k_get_arvif(ar, __le32_to_cpu(ev->vdev_id)); + ieee80211_tdls_oper_request( arvif->vif, station->addr, NL80211_TDLS_TEARDOWN, WLAN_REASON_TDLS_TEARDOWN_UNREACHABLE, GFP_ATOMIC ); + } + rcu_read_unlock(); break; } -exit: - rcu_read_unlock(); kfree(tb); }
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