Re: [PATCH v3 net-next 3/8] sctp: Don't call sk->sk_prot->init() in sctp_v[46]_create_accept_sk().

On Thu, Oct 23, 2025 at 7:17 PM Kuniyuki Iwashima <[email protected]> wrote:
>
> sctp_accept() calls sctp_v[46]_create_accept_sk() to allocate a new
> socket and calls sctp_sock_migrate() to copy fields from the parent
> socket to the new socket.
>
> sctp_v[46]_create_accept_sk() calls sctp_init_sock() to initialise
> sctp_sock, but most fields are overwritten by sctp_copy_descendant()
> called from sctp_sock_migrate().
>
> Things done in sctp_init_sock() but not in sctp_sock_migrate() are
> the following:
>
>   1. Copy sk->sk_gso
>   2. Copy sk->sk_destruct (sctp_v6_init_sock())
>   3. Allocate sctp_sock.ep
>   4. Initialise sctp_sock.pd_lobby
>   5. Count sk_sockets_allocated_inc(), sock_prot_inuse_add(),
>      and SCTP_DBG_OBJCNT_INC()
>
> Let's do these in sctp_copy_sock() and sctp_sock_migrate() and avoid
> calling sk->sk_prot->init() in sctp_v[46]_create_accept_sk().
>
> Note that sk->sk_destruct is already copied in sctp_copy_sock().
>
> Signed-off-by: Kuniyuki Iwashima <[email protected]>
Acked-by: Xin Long <[email protected]>