Subject: Re: [PATCH net] sctp: only drop the reference on the datamsg after sending a msg

From: Marcelo Ricardo Leitner <[email-masked]>
Date: Sat, 5 Dec 2015 08:31:11 -0200

Em 05-12-2015 05:19, Xin Long escreveu:
> If the chunks are enqueued successfully but sctp_cmd_interpreter()
> return err to sctp_sendmsg() (mainly because of no mem), the chunks will
> get re-queued, but we are dropping the reference and freeing them.
>
> The fix is to just drop the reference on the datamsg just as it had
> succeeded, as:
>   - if the chunks weren't queued, this is enough to get them freed.
>   - if they were queued, they will get freed when they finally get out or
>   discarded.
>
> Signed-off-by: Xin Long <[email-masked]>
> Marcelo Ricardo Leitner <[email-masked]>

Signed-off-by: Marcelo Ricardo Leitner <[email-masked]>

Thanks Xin

> ---
>   net/sctp/socket.c | 6 ++----
>   1 file changed, 2 insertions(+), 4 deletions(-)
>
> diff --git a/net/sctp/socket.c b/net/sctp/socket.c
> index 03c8256..d8460be 100644
> --- a/net/sctp/socket.c
> +++ b/net/sctp/socket.c
> @@ -1966,15 +1966,13 @@ static int sctp_sendmsg(struct sock *sk, struct msghdr *msg, size_t msg_len)
>   	 * breaks.
>   	 */
>   	err = sctp_primitive_SEND(net, asoc, datamsg);
> +	sctp_datamsg_put(datamsg);
>   	/* Did the lower layer accept the chunk? */
> -	if (err) {
> -		sctp_datamsg_free(datamsg);
> +	if (err)
>   		goto out_free;
> -	}
>
>   	pr_debug("%s: we sent primitively\n", __func__);
>
> -	sctp_datamsg_put(datamsg);
>   	err = msg_len;
>
>   	if (unlikely(wait_connect)) {
>