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From:   Toke =?utf-8?Q?H=C3=B8iland-J=C3=B8rgensen?= <toke@kernel.org>
To:     Felix Fietkau <nbd@nbd.name>, linux-wireless@vger.kernel.org
Cc:     johannes@sipsolutions.net
Subject: Re: [PATCH] mac80211: do not wake queues on a vif that is being
 stopped
In-Reply-To: <20220531190824.60019-1-nbd@nbd.name>
References: <20220531190824.60019-1-nbd@nbd.name>
Date:   Sun, 05 Jun 2022 19:23:37 +0200
Message-ID: <874k0zowh2.fsf@toke.dk>
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Felix Fietkau <nbd@nbd.name> writes:

> When a vif is being removed and sdata->bss is cleared, __ieee80211_wake_t=
xqs
> can still be called on it, which crashes as soon as sdata->bss is being
> dereferenced.
> To fix this properly, check for SDATA_STATE_RUNNING before waking queues,
> and take the fq lock when setting it (to ensure that __ieee80211_wake_txqs
> observes the change when running on a different CPU
>
> Signed-off-by: Felix Fietkau <nbd@nbd.name>

I think it's a little ugly to expand usage of fq.lock across more and
more places, I don't really have a good alternative, so:

Acked-by: Toke H=C3=B8iland-J=C3=B8rgensen <toke@kernel.org>