On Tue, Feb 21, 2023 at 10:22 AM Hangyu Hua <hbh25y@xxxxxxxxx> wrote:
>
> A useless record can be insert into av_records when dccp_insert_options()
> fails after dccp_insert_option_ackvec(). Repeated triggering may cause
> av_records to have a lot of useless record with the same avr_ack_seqno.
>
> Fixes: 8b7b6c75c638 ("dccp: Integrate feature-negotiation insertion code")
> Signed-off-by: Hangyu Hua <hbh25y@xxxxxxxxx>
> ---
> net/dccp/options.c | 12 ++++++++++--
> 1 file changed, 10 insertions(+), 2 deletions(-)
>
> diff --git a/net/dccp/options.c b/net/dccp/options.c
> index d24cad05001e..8aa4abeb15ea 100644
> --- a/net/dccp/options.c
> +++ b/net/dccp/options.c
> @@ -549,6 +549,8 @@ static void dccp_insert_option_padding(struct sk_buff *skb)
> int dccp_insert_options(struct sock *sk, struct sk_buff *skb)
> {
> struct dccp_sock *dp = dccp_sk(sk);
> + struct dccp_ackvec *av = dp->dccps_hc_rx_ackvec;
> + struct dccp_ackvec_record *avr;
>
> DCCP_SKB_CB(skb)->dccpd_opt_len = 0;
>
> @@ -577,16 +579,22 @@ int dccp_insert_options(struct sock *sk, struct sk_buff *skb)
>
> if (dp->dccps_hc_rx_insert_options) {
> if (ccid_hc_rx_insert_options(dp->dccps_hc_rx_ccid, sk, skb))
> - return -1;
> + goto delete_ackvec;
> dp->dccps_hc_rx_insert_options = 0;
> }
>
> if (dp->dccps_timestamp_echo != 0 &&
> dccp_insert_option_timestamp_echo(dp, NULL, skb))
> - return -1;
> + goto delete_ackvec;
>
> dccp_insert_option_padding(skb);
> return 0;
> +
> +delete_ackvec:
> + avr = dccp_ackvec_lookup(&av->av_records, DCCP_SKB_CB(skb)->dccpd_seq);
Why avr would be not NULL ?
> + list_del(&avr->avr_node);
> + kmem_cache_free(dccp_ackvec_record_slab, avr);
> + return -1;
> }
Are you really using DCCP and/or how have you tested this patch ?
net/dccp/ackvec.c:15:static struct kmem_cache *dccp_ackvec_record_slab;
I doubt this patch has been compiled.
I would rather mark DCCP deprecated and stop trying to fix it.
