Re: [PATCH net] net/smc: fix TOCTOU race between smc_listen_out() and listener close

> @@ -1931,11 +1931,12 @@ static void smc_listen_out(struct smc_sock *new_smc)
>  		atomic_dec(&lsmc->queued_smc_hs);
>  
>  	release_sock(newsmcsk); /* lock in smc_listen_work() */
> +	lock_sock_nested(&lsmc->sk, SINGLE_DEPTH_NESTING);
>  	if (lsmc->sk.sk_state == SMC_LISTEN) {
> -		lock_sock_nested(&lsmc->sk, SINGLE_DEPTH_NESTING);
>  		smc_accept_enqueue(&lsmc->sk, newsmcsk);
>  		release_sock(&lsmc->sk);
>  	} else { /* no longer listening */
> +		release_sock(&lsmc->sk);
>  		smc_close_non_accepted(newsmcsk);
>  	}

Do you need to call smc_close_non_accepted() without the lock? otherwise
you can have the lock around the whole if/else clause.