Re: [PATCH v4] wifi: mac80211: fix monitor mode frame capture for real chanctx drivers

[Johannes Berg]

On Tue, 2026-05-19 at 16:57 -0700, Devin Wittmayer wrote:
> 
> Cc: stable@xxxxxxxxxxxxxxx # 6.9+

No. It's known to crash drivers on some versions, so it should
explicitly opt out of stable by

Cc: <stable+noautosel@xxxxxxxxxx> # causes some older drivers to crash


> -	if (chanctx_conf)
> +	if (chanctx_conf) {
>  		chandef = &chanctx_conf->def;
> -	else if (local->emulate_chanctx)
> -		chandef = &local->hw.conf.chandef;
> -	else
> -		goto fail_rcu;
> +	} else {
> +		struct ieee80211_chanctx *ctx;
> +
> +		ctx = list_first_or_null_rcu(&local->chanctx_list,
> +					     struct ieee80211_chanctx, list);
> +		if (!ctx ||
> +		    rcu_access_pointer(ctx->list.next) != &local->chanctx_list)
> +			goto fail_rcu;

This results in a sparse warning, maybe my loop approach was better
after all.

johannes