On Fri, May 29, 2020 at 02:09:41PM +0200, Christoph Hellwig wrote:
> Split out a sctp_setsockopt_bindx_kernel that takes a kernel pointer
> to the sockaddr and make sctp_setsockopt_bindx a small wrapper around
> it. This prepares for adding a new bind_add proto op.
>
> Signed-off-by: Christoph Hellwig <hch@xxxxxx>
Acked-by: Marcelo Ricardo Leitner <marcelo.leitner@xxxxxxxxx>
> ---
> net/sctp/socket.c | 61 ++++++++++++++++++++++-------------------------
> 1 file changed, 28 insertions(+), 33 deletions(-)
>
> diff --git a/net/sctp/socket.c b/net/sctp/socket.c
> index 827a9903ee288..6e745ac3c4a59 100644
> --- a/net/sctp/socket.c
> +++ b/net/sctp/socket.c
> @@ -972,23 +972,22 @@ int sctp_asconf_mgmt(struct sctp_sock *sp, struct sctp_sockaddr_entry *addrw)
> * it.
> *
> * sk The sk of the socket
> - * addrs The pointer to the addresses in user land
> + * addrs The pointer to the addresses
> * addrssize Size of the addrs buffer
> * op Operation to perform (add or remove, see the flags of
> * sctp_bindx)
> *
> * Returns 0 if ok, <0 errno code on error.
> */
> -static int sctp_setsockopt_bindx(struct sock *sk,
> - struct sockaddr __user *addrs,
> - int addrs_size, int op)
> +static int sctp_setsockopt_bindx_kernel(struct sock *sk,
> + struct sockaddr *addrs, int addrs_size,
> + int op)
> {
> - struct sockaddr *kaddrs;
> int err;
> int addrcnt = 0;
> int walk_size = 0;
> struct sockaddr *sa_addr;
> - void *addr_buf;
> + void *addr_buf = addrs;
> struct sctp_af *af;
>
> pr_debug("%s: sk:%p addrs:%p addrs_size:%d opt:%d\n",
> @@ -997,17 +996,10 @@ static int sctp_setsockopt_bindx(struct sock *sk,
> if (unlikely(addrs_size <= 0))
> return -EINVAL;
>
> - kaddrs = memdup_user(addrs, addrs_size);
> - if (IS_ERR(kaddrs))
> - return PTR_ERR(kaddrs);
> -
> /* Walk through the addrs buffer and count the number of addresses. */
> - addr_buf = kaddrs;
> while (walk_size < addrs_size) {
> - if (walk_size + sizeof(sa_family_t) > addrs_size) {
> - kfree(kaddrs);
> + if (walk_size + sizeof(sa_family_t) > addrs_size)
> return -EINVAL;
> - }
>
> sa_addr = addr_buf;
> af = sctp_get_af_specific(sa_addr->sa_family);
> @@ -1015,10 +1007,8 @@ static int sctp_setsockopt_bindx(struct sock *sk,
> /* If the address family is not supported or if this address
> * causes the address buffer to overflow return EINVAL.
> */
> - if (!af || (walk_size + af->sockaddr_len) > addrs_size) {
> - kfree(kaddrs);
> + if (!af || (walk_size + af->sockaddr_len) > addrs_size)
> return -EINVAL;
> - }
> addrcnt++;
> addr_buf += af->sockaddr_len;
> walk_size += af->sockaddr_len;
> @@ -1029,31 +1019,36 @@ static int sctp_setsockopt_bindx(struct sock *sk,
> case SCTP_BINDX_ADD_ADDR:
> /* Allow security module to validate bindx addresses. */
> err = security_sctp_bind_connect(sk, SCTP_SOCKOPT_BINDX_ADD,
> - (struct sockaddr *)kaddrs,
> - addrs_size);
> + addrs, addrs_size);
> if (err)
> - goto out;
> - err = sctp_bindx_add(sk, kaddrs, addrcnt);
> + return err;
> + err = sctp_bindx_add(sk, addrs, addrcnt);
> if (err)
> - goto out;
> - err = sctp_send_asconf_add_ip(sk, kaddrs, addrcnt);
> - break;
> -
> + return err;
> + return sctp_send_asconf_add_ip(sk, addrs, addrcnt);
> case SCTP_BINDX_REM_ADDR:
> - err = sctp_bindx_rem(sk, kaddrs, addrcnt);
> + err = sctp_bindx_rem(sk, addrs, addrcnt);
> if (err)
> - goto out;
> - err = sctp_send_asconf_del_ip(sk, kaddrs, addrcnt);
> - break;
> + return err;
> + return sctp_send_asconf_del_ip(sk, addrs, addrcnt);
>
> default:
> - err = -EINVAL;
> - break;
> + return -EINVAL;
> }
> +}
>
> -out:
> - kfree(kaddrs);
> +static int sctp_setsockopt_bindx(struct sock *sk,
> + struct sockaddr __user *addrs,
> + int addrs_size, int op)
> +{
> + struct sockaddr *kaddrs;
> + int err;
>
> + kaddrs = memdup_user(addrs, addrs_size);
> + if (IS_ERR(kaddrs))
> + return PTR_ERR(kaddrs);
> + err = sctp_setsockopt_bindx_kernel(sk, kaddrs, addrs_size, op);
> + kfree(kaddrs);
> return err;
> }
>
> --
> 2.26.2
>
