Re: [PATCH net-next] ipvs: properly dereference pe in ip_vs_add_service
Julian Anastasov <[email protected]>
| Newsgroups | org.kernel.vger.lvs-devel,org.kernel.vger.netdev,org.kernel.vger.netfilter-devel |
|---|---|
| Message-ID | <[email protected]> |
Hello,
On Wed, 26 Jun 2024, Chen Hanxiao wrote:
> Use rcu_dereference_protected to resolve sparse warning:
>
> net/netfilter/ipvs/ip_vs_ctl.c:1471:27: warning: dereference of noderef expression
>
> Fixes: 39b972231536 ("ipvs: handle connections started by real-servers")
> Signed-off-by: Chen Hanxiao <[email protected]>
> ---
> net/netfilter/ipvs/ip_vs_ctl.c | 5 +++--
> 1 file changed, 3 insertions(+), 2 deletions(-)
>
> diff --git a/net/netfilter/ipvs/ip_vs_ctl.c b/net/netfilter/ipvs/ip_vs_ctl.c
> index b6d0dcf3a5c3..925e2143ba15 100644
> --- a/net/netfilter/ipvs/ip_vs_ctl.c
> +++ b/net/netfilter/ipvs/ip_vs_ctl.c
> @@ -1369,7 +1369,7 @@ ip_vs_add_service(struct netns_ipvs *ipvs, struct ip_vs_service_user_kern *u,
> {
> int ret = 0;
> struct ip_vs_scheduler *sched = NULL;
> - struct ip_vs_pe *pe = NULL;
> + struct ip_vs_pe *pe = NULL, *tmp_pe = NULL;
NULL init is not needed
> struct ip_vs_service *svc = NULL;
> int ret_hooks = -1;
>
> @@ -1468,7 +1468,8 @@ ip_vs_add_service(struct netns_ipvs *ipvs, struct ip_vs_service_user_kern *u,
> atomic_inc(&ipvs->ftpsvc_counter);
> else if (svc->port == 0)
> atomic_inc(&ipvs->nullsvc_counter);
> - if (svc->pe && svc->pe->conn_out)
> + tmp_pe = rcu_dereference_protected(svc->pe, 1);
> + if (tmp_pe && tmp_pe->conn_out)
> atomic_inc(&ipvs->conn_out_counter);
Alternative option would be to use 'pe' above and to move
the RCU_INIT_POINTER and pe = NULL with their comment here.
It is up to you to decide which option is better...
Regards
--
Julian Anastasov <[email protected]>