Re: [PATCH net-next v2 3/3] af_unix: Clean up error handling in unix_listen()

[Kuniyuki Iwashima]

On Fri, Jul 3, 2026 at 1:15 AM John Ericson
<John.Ericson@obsidian.systems> wrote:
>
> From: John Ericson <mail@xxxxxxxxxxxxxx>
>
> To avoid the sort of bug that was just fixed going forward, switch to a
> style where `err = -E...;` instead happens right before the `goto`.
> (`err = other_function(...);` is not changed.) Then there is no
> spooky-action-at-a-distance between the `err` initialization and the
> `goto`, something which is easier to slip by code review.

Sorry, I meant posting this separately to net-next.git after the
patch 1 is merged to net.git and lands net-next.git.

Also could you remove markdown `` ?


>
> Assisted-by: Claude:claude-fable-5
> Signed-off-by: John Ericson <mail@xxxxxxxxxxxxxx>
> ---
>  net/unix/af_unix.c | 15 +++++++++------
>  1 file changed, 9 insertions(+), 6 deletions(-)
>
> diff --git a/net/unix/af_unix.c b/net/unix/af_unix.c
> index 10ed9421e43a..7878b27bbaf8 100644
> --- a/net/unix/af_unix.c
> +++ b/net/unix/af_unix.c
> @@ -813,19 +813,22 @@ static int unix_listen(struct socket *sock, int backlog)
>         struct unix_sock *u = unix_sk(sk);
>         struct unix_peercred peercred = {};
>
> -       err = -EOPNOTSUPP;
> -       if (sock->type != SOCK_STREAM && sock->type != SOCK_SEQPACKET)
> +       if (sock->type != SOCK_STREAM && sock->type != SOCK_SEQPACKET) {
> +               err = -EOPNOTSUPP;
>                 goto out;       /* Only stream/seqpacket sockets accept */
> -       err = -EINVAL;
> -       if (!READ_ONCE(u->addr))
> +       }
> +       if (!READ_ONCE(u->addr)) {
> +               err = -EINVAL;
>                 goto out;       /* No listens on an unbound socket */
> +       }
>         err = prepare_peercred(&peercred);
>         if (err)
>                 goto out;
>         unix_state_lock(sk);
> -       err = -EINVAL;
> -       if (sk->sk_state != TCP_CLOSE && sk->sk_state != TCP_LISTEN)
> +       if (sk->sk_state != TCP_CLOSE && sk->sk_state != TCP_LISTEN) {
> +               err = -EINVAL;
>                 goto out_unlock;
> +       }
>         if (backlog > sk->sk_max_ack_backlog)
>                 wake_up_interruptible_all(&u->peer_wait);
>         sk->sk_max_ack_backlog  = backlog;
> --
> 2.54.0
>