netfilter: xt_CT: fix refcnt leak on error path

There are two cases which causes refcnt leak.

1. When nf_ct_timeout_ext_add failed in xt_ct_set_timeout, it should
free the timeout refcnt.
Now goto the err_put_timeout error handler instead of going ahead.

2. When the time policy is not found, we should call module_put.
Otherwise, the related cthelper module cannot be removed anymore.
It is easy to reproduce by typing the following command:
  # iptables -t raw -A OUTPUT -p tcp -j CT --helper ftp --timeout xxx

Signed-off-by: Gao Feng <fgao@ikuai8.com>
Signed-off-by: Liping Zhang <zlpnobody@gmail.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
This commit is contained in:
Gao Feng 2017-04-14 10:00:08 +08:00 committed by Pablo Neira Ayuso
parent 94836ecf1e
commit 470acf55a0
1 changed files with 9 additions and 2 deletions

View File

@ -167,8 +167,10 @@ xt_ct_set_timeout(struct nf_conn *ct, const struct xt_tgchk_param *par,
goto err_put_timeout;
}
timeout_ext = nf_ct_timeout_ext_add(ct, timeout, GFP_ATOMIC);
if (timeout_ext == NULL)
if (!timeout_ext) {
ret = -ENOMEM;
goto err_put_timeout;
}
rcu_read_unlock();
return ret;
@ -200,6 +202,7 @@ static int xt_ct_tg_check(const struct xt_tgchk_param *par,
struct xt_ct_target_info_v1 *info)
{
struct nf_conntrack_zone zone;
struct nf_conn_help *help;
struct nf_conn *ct;
int ret = -EOPNOTSUPP;
@ -248,7 +251,7 @@ static int xt_ct_tg_check(const struct xt_tgchk_param *par,
if (info->timeout[0]) {
ret = xt_ct_set_timeout(ct, par, info->timeout);
if (ret < 0)
goto err3;
goto err4;
}
__set_bit(IPS_CONFIRMED_BIT, &ct->status);
nf_conntrack_get(&ct->ct_general);
@ -256,6 +259,10 @@ static int xt_ct_tg_check(const struct xt_tgchk_param *par,
info->ct = ct;
return 0;
err4:
help = nfct_help(ct);
if (help)
module_put(help->helper->me);
err3:
nf_ct_tmpl_free(ct);
err2: