netfilter: nfnl_cthelper: fix incorrect helper->expect_class_max
The helper->expect_class_max must be set to the total number of expect_policy minus 1, since we will use the statement "if (class > helper->expect_class_max)" to validate the CTA_EXPECT_CLASS attr in ctnetlink_alloc_expect. So for compatibility, set the helper->expect_class_max to the NFCTH_POLICY_SET_NUM attr's value minus 1. Also: it's invalid when the NFCTH_POLICY_SET_NUM attr's value is zero. 1. this will result "expect_policy = kzalloc(0, GFP_KERNEL);"; 2. we cannot set the helper->expect_class_max to a proper value. So if nla_get_be32(tb[NFCTH_POLICY_SET_NUM]) is zero, report -EINVAL to the userspace. Signed-off-by: Liping Zhang <zlpnobody@gmail.com> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
This commit is contained in:
parent
db7f00b8db
commit
ae5c682113
|
@ -161,6 +161,7 @@ nfnl_cthelper_parse_expect_policy(struct nf_conntrack_helper *helper,
|
|||
int i, ret;
|
||||
struct nf_conntrack_expect_policy *expect_policy;
|
||||
struct nlattr *tb[NFCTH_POLICY_SET_MAX+1];
|
||||
unsigned int class_max;
|
||||
|
||||
ret = nla_parse_nested(tb, NFCTH_POLICY_SET_MAX, attr,
|
||||
nfnl_cthelper_expect_policy_set);
|
||||
|
@ -170,19 +171,18 @@ nfnl_cthelper_parse_expect_policy(struct nf_conntrack_helper *helper,
|
|||
if (!tb[NFCTH_POLICY_SET_NUM])
|
||||
return -EINVAL;
|
||||
|
||||
helper->expect_class_max =
|
||||
ntohl(nla_get_be32(tb[NFCTH_POLICY_SET_NUM]));
|
||||
|
||||
if (helper->expect_class_max != 0 &&
|
||||
helper->expect_class_max > NF_CT_MAX_EXPECT_CLASSES)
|
||||
class_max = ntohl(nla_get_be32(tb[NFCTH_POLICY_SET_NUM]));
|
||||
if (class_max == 0)
|
||||
return -EINVAL;
|
||||
if (class_max > NF_CT_MAX_EXPECT_CLASSES)
|
||||
return -EOVERFLOW;
|
||||
|
||||
expect_policy = kzalloc(sizeof(struct nf_conntrack_expect_policy) *
|
||||
helper->expect_class_max, GFP_KERNEL);
|
||||
class_max, GFP_KERNEL);
|
||||
if (expect_policy == NULL)
|
||||
return -ENOMEM;
|
||||
|
||||
for (i=0; i<helper->expect_class_max; i++) {
|
||||
for (i = 0; i < class_max; i++) {
|
||||
if (!tb[NFCTH_POLICY_SET+i])
|
||||
goto err;
|
||||
|
||||
|
@ -191,6 +191,8 @@ nfnl_cthelper_parse_expect_policy(struct nf_conntrack_helper *helper,
|
|||
if (ret < 0)
|
||||
goto err;
|
||||
}
|
||||
|
||||
helper->expect_class_max = class_max - 1;
|
||||
helper->expect_policy = expect_policy;
|
||||
return 0;
|
||||
err:
|
||||
|
@ -377,10 +379,10 @@ nfnl_cthelper_dump_policy(struct sk_buff *skb,
|
|||
goto nla_put_failure;
|
||||
|
||||
if (nla_put_be32(skb, NFCTH_POLICY_SET_NUM,
|
||||
htonl(helper->expect_class_max)))
|
||||
htonl(helper->expect_class_max + 1)))
|
||||
goto nla_put_failure;
|
||||
|
||||
for (i=0; i<helper->expect_class_max; i++) {
|
||||
for (i = 0; i < helper->expect_class_max + 1; i++) {
|
||||
nest_parms2 = nla_nest_start(skb,
|
||||
(NFCTH_POLICY_SET+i) | NLA_F_NESTED);
|
||||
if (nest_parms2 == NULL)
|
||||
|
|
Loading…
Reference in New Issue