| Message ID | 20210212021312.40486-2-skhan@linuxfoundation.org (mailing list archive) |
|---|---|
| State | Changes Requested |
| Delegated to: | Kalle Valo |
| Headers | show |
| Series | rtw88: hold RCU lock when calling ieee80211_find_sta_by_ifaddr() | expand |
On 2021-02-12 03:13, Shuah Khan wrote: > 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 rtw_rx_addr_match_iter() to hold RCU read 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() and a subsequent manual audit > of other callers of ieee80211_find_sta_by_ifaddr() that don't hold > RCU read lock. > > Signed-off-by: Shuah Khan <skhan@linuxfoundation.org> This one also seems unnecessary. rtw_rx_addr_match_iter is called by ieee80211_iterate_active_interfaces_atomic, which acquires the RCU read lock before calling it. - Felix
diff --git a/drivers/net/wireless/realtek/rtw88/rx.c b/drivers/net/wireless/realtek/rtw88/rx.c index 7087e385a9b3..4ab3d3e2bfab 100644 --- a/drivers/net/wireless/realtek/rtw88/rx.c +++ b/drivers/net/wireless/realtek/rtw88/rx.c @@ -111,6 +111,9 @@ static void rtw_rx_addr_match_iter(void *data, u8 *mac, return; rtw_rx_phy_stat(rtwdev, pkt_stat, hdr); + + rcu_read_lock(); + sta = ieee80211_find_sta_by_ifaddr(rtwdev->hw, hdr->addr2, vif->addr); if (!sta) @@ -118,6 +121,9 @@ static void rtw_rx_addr_match_iter(void *data, u8 *mac, si = (struct rtw_sta_info *)sta->drv_priv; ewma_rssi_add(&si->avg_rssi, pkt_stat->rssi); + +exit: + rcu_read_unlock(); } static void rtw_rx_addr_match(struct rtw_dev *rtwdev,
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 rtw_rx_addr_match_iter() to hold RCU read 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() and a subsequent manual audit of other callers of ieee80211_find_sta_by_ifaddr() that don't hold RCU read lock. Signed-off-by: Shuah Khan <skhan@linuxfoundation.org> --- - Note: This patch is compile tested. I don't have access to hardware. drivers/net/wireless/realtek/rtw88/rx.c | 6 ++++++ 1 file changed, 6 insertions(+)