2021-02-12 06:36:56

by Felix Fietkau

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Subject: Re: [PATCH] rtw88: hold RCU lock when calling ieee80211_find_sta_by_ifaddr()

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 <[email protected]>
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