Re: [nf-next:master 2/3] net/netfilter/ipvs/ip_vs_conn.c:1394:6: sparse: sparse: context imbalance in 'ip_vs_expire_nodest_conn_flush' - wrong count at exit

[Julian Anastasov <ja@xxxxxx>]

	Hello,

On Thu, 16 Jul 2020, Pablo Neira Ayuso wrote:

> On Thu, Jul 16, 2020 at 10:42:53PM +0800, kernel test robot wrote:
> > 
> > # https://git.kernel.org/pub/scm/linux/kernel/git/pablo/nf-next.git/commit/?id=04231e52d3557475231abe8a8fa1be0330826ed6
> > git remote add nf-next https://git.kernel.org/pub/scm/linux/kernel/git/pablo/nf-next.git
> > git remote update nf-next
> > git checkout 04231e52d3557475231abe8a8fa1be0330826ed6
> > vim +/ip_vs_expire_nodest_conn_flush +1394 net/netfilter/ipvs/ip_vs_conn.c
> > 
> > 04231e52d355747 Andrew Sy Kim 2020-07-08  1392  
> > 04231e52d355747 Andrew Sy Kim 2020-07-08  1393  #ifdef CONFIG_SYSCTL
> > 04231e52d355747 Andrew Sy Kim 2020-07-08 @1394  void ip_vs_expire_nodest_conn_flush(struct netns_ipvs *ipvs)
> > 04231e52d355747 Andrew Sy Kim 2020-07-08  1395  {
> > 04231e52d355747 Andrew Sy Kim 2020-07-08  1396  	int idx;
> > 04231e52d355747 Andrew Sy Kim 2020-07-08  1397  	struct ip_vs_conn *cp, *cp_c;
> > 04231e52d355747 Andrew Sy Kim 2020-07-08  1398  	struct ip_vs_dest *dest;
> > 04231e52d355747 Andrew Sy Kim 2020-07-08  1399  
> > 04231e52d355747 Andrew Sy Kim 2020-07-08  1400  	rcu_read_lock();
> > 04231e52d355747 Andrew Sy Kim 2020-07-08  1401  	for (idx = 0; idx < ip_vs_conn_tab_size; idx++) {
> > 04231e52d355747 Andrew Sy Kim 2020-07-08  1402  		hlist_for_each_entry_rcu(cp, &ip_vs_conn_tab[idx], c_list) {
> > 04231e52d355747 Andrew Sy Kim 2020-07-08  1403  			if (cp->ipvs != ipvs)
> > 04231e52d355747 Andrew Sy Kim 2020-07-08  1404  				continue;
> > 04231e52d355747 Andrew Sy Kim 2020-07-08  1405  
> > 04231e52d355747 Andrew Sy Kim 2020-07-08  1406  			dest = cp->dest;
> > 04231e52d355747 Andrew Sy Kim 2020-07-08  1407  			if (!dest || (dest->flags & IP_VS_DEST_F_AVAILABLE))
> > 04231e52d355747 Andrew Sy Kim 2020-07-08  1408  				continue;
> > 04231e52d355747 Andrew Sy Kim 2020-07-08  1409  
> > 04231e52d355747 Andrew Sy Kim 2020-07-08  1410  			if (atomic_read(&cp->n_control))
> > 04231e52d355747 Andrew Sy Kim 2020-07-08  1411  				continue;
> > 04231e52d355747 Andrew Sy Kim 2020-07-08  1412  
> > 04231e52d355747 Andrew Sy Kim 2020-07-08  1413  			cp_c = cp->control;
> > 04231e52d355747 Andrew Sy Kim 2020-07-08  1414  			IP_VS_DBG(4, "del connection\n");
> > 04231e52d355747 Andrew Sy Kim 2020-07-08  1415  			ip_vs_conn_del(cp);
> > 04231e52d355747 Andrew Sy Kim 2020-07-08  1416  			if (cp_c && !atomic_read(&cp_c->n_control)) {
> > 04231e52d355747 Andrew Sy Kim 2020-07-08  1417  				IP_VS_DBG(4, "del controlling connection\n");
> > 04231e52d355747 Andrew Sy Kim 2020-07-08  1418  				ip_vs_conn_del(cp_c);
> > 04231e52d355747 Andrew Sy Kim 2020-07-08  1419  			}
> > 04231e52d355747 Andrew Sy Kim 2020-07-08  1420  		}
> > 04231e52d355747 Andrew Sy Kim 2020-07-08  1421  		cond_resched_rcu();
> > 04231e52d355747 Andrew Sy Kim 2020-07-08  1422  
> > 04231e52d355747 Andrew Sy Kim 2020-07-08  1423  		/* netns clean up started, abort delayed work */
> > 04231e52d355747 Andrew Sy Kim 2020-07-08  1424  		if (!ipvs->enable)
> > 04231e52d355747 Andrew Sy Kim 2020-07-08  1425  			return;
> 
>                                         Missing rcu_read_unlock() here ?

	I suggested this code with a 'break' but later didn't
notice it is a 'return'... May be Andrew will provide a fix?

Regards

--
Julian Anastasov <ja@xxxxxx>