Tetsuo Handa <penguin-kernel@xxxxxxxxxxxxxxxxxxx> wrote:
> lockdep complains use of uninitialized spinlock at ieee80211_do_stop() [1],
> for commit f856373e2f31ffd3 ("wifi: mac80211: do not wake queues on a vif
> that is being stopped") guards clear_bit() using fq.lock even before
> fq_init() from ieee80211_txq_setup_flows() initializes this spinlock.
>
> According to discussion [2], Toke was not happy with expanding usage of
> fq.lock. Since __ieee80211_wake_txqs() is called under RCU read lock, we
> can instead use synchronize_rcu() for flushing ieee80211_wake_txqs().
>
> Link: https://syzkaller.appspot.com/bug?extid=eceab52db7c4b961e9d6 [1]
> Link: https://lkml.kernel.org/r/874k0zowh2.fsf@xxxxxxx [2]
> Reported-by: syzbot <syzbot+eceab52db7c4b961e9d6@xxxxxxxxxxxxxxxxxxxxxxxxx>
> Signed-off-by: Tetsuo Handa <penguin-kernel@xxxxxxxxxxxxxxxxxxx>
> Fixes: f856373e2f31ffd3 ("wifi: mac80211: do not wake queues on a vif that is being stopped")
> Tested-by: syzbot <syzbot+eceab52db7c4b961e9d6@xxxxxxxxxxxxxxxxxxxxxxxxx>
> Acked-by: Toke Høiland-Jørgensen <toke@xxxxxxxxxx>
Patch applied to wireless-next.git, thanks.
3598cb6e1862 wifi: mac80211: do not abuse fq.lock in ieee80211_do_stop()
--
https://patchwork.kernel.org/project/linux-wireless/patch/9cc9b81d-75a3-3925-b612-9d0ad3cab82b@xxxxxxxxxxxxxxxxxxx/
https://wireless.wiki.kernel.org/en/developers/documentation/submittingpatches
