Re: [PATCH] mac80211: fix RCU usage in ieee80211_tx_h_select_key()

[Johannes Berg]

> 
> ieee80211_tx_h_select_key() is performing a series of RCU dereferences, 
> but none of the callers seems to be taking RCU read-side lock; let's 
> acquire the lock in ieee80211_tx_h_select_key() itself.
> 
but but ...

>   ieee80211_tx_dequeue+0x1a7/0x1260 [mac80211 911c23e2351c0ae60b597a67b1204a5ea955e365]
>   rtw89_core_txq_work+0x1a6/0x420 [rtw89_core b39ba493f2e517ad75e0f8187ecc24edf58bbbea]

/**
 * ieee80211_tx_dequeue - dequeue a packet from a software tx queue
 *
 * @hw: pointer as obtained from ieee80211_alloc_hw()
 * @txq: pointer obtained from station or virtual interface, or from
 *      ieee80211_next_txq()
 *
 * Returns the skb if successful, %NULL if no frame was available.
 *
 * Note that this must be called in an rcu_read_lock() critical section,
 * which can only be released after the SKB was handled. Some pointers in
[...]

-> driver bug?

johannes