Re: [PATCH v3] net: mac80211: Add NULL checks for sta->sdata

From: Johannes Berg
Date: Tue Apr 11 2023 - 06:35:38 EST


On Tue, 2023-04-04 at 20:47 +0800, Jia-Ju Bai wrote:
> In a previous commit 69403bad97aa ("wifi: mac80211: sdata can be NULL
> during AMPDU start"), sta->sdata can be NULL, and thus it should be
> checked before being used.

Right.

> However, in the same call stack, sta->sdata is also used in the
> following functions:
>

Fun, guess we should fix that too then.

Honestly though, I don't think this patch is the right way of going
about it. It seems that instead we should expand the checks in the
previous patch - see how it's talking about a race, and we don't really
want or need to handle aggregation for a station that's being removed.

So I think the better way to fix it would be to prevent the race more
clearly, though off the top of my head I'm not sure how we'd do that.

johannes