From: Shuah Khan skhan@linuxfoundation.org
[ 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@... Signed-off-by: Shuah Khan skhan@linuxfoundation.org Signed-off-by: Kalle Valo kvalo@codeaurora.org Link: https://lore.kernel.org/r/20210210212107.40373-1-skhan@linuxfoundation.org Signed-off-by: Sasha Levin sashal@kernel.org --- 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 3ec71f52e8fe..d38276ac375e 100644 --- a/drivers/net/wireless/ath/ath10k/wmi-tlv.c +++ b/drivers/net/wireless/ath/ath10k/wmi-tlv.c @@ -445,13 +445,13 @@ 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( @@ -462,6 +462,9 @@ static void ath10k_wmi_event_tdls_peer(struct ath10k *ar, struct sk_buff *skb) ); break; } + +exit: + rcu_read_unlock(); kfree(tb); }