From 92f73221f9e9e143d242e3eca9c512dac969765e Mon Sep 17 00:00:00 2001 From: Gao Feng Date: Fri, 24 Mar 2017 21:32:19 +0800 Subject: [PATCH] netfilter: expect: Make sure the max_expected limit is effective Because the type of expecting, the member of nf_conn_help, is u8, it would overflow after reach U8_MAX(255). So it doesn't work when we configure the max_expected exceeds 255 with expect policy. Now add the check for max_expected. Return the -EINVAL when it exceeds the limit. Signed-off-by: Gao Feng Signed-off-by: Pablo Neira Ayuso --- include/net/netfilter/nf_conntrack_expect.h | 1 + net/netfilter/nf_conntrack_helper.c | 3 +++ net/netfilter/nf_conntrack_irc.c | 6 ++++++ net/netfilter/nfnetlink_cthelper.c | 6 ++++++ 4 files changed, 16 insertions(+) diff --git a/include/net/netfilter/nf_conntrack_expect.h b/include/net/netfilter/nf_conntrack_expect.h index 65cc2cb005d9..e84df8d3bf37 100644 --- a/include/net/netfilter/nf_conntrack_expect.h +++ b/include/net/netfilter/nf_conntrack_expect.h @@ -73,6 +73,7 @@ struct nf_conntrack_expect_policy { }; #define NF_CT_EXPECT_CLASS_DEFAULT 0 +#define NF_CT_EXPECT_MAX_CNT 255 int nf_conntrack_expect_pernet_init(struct net *net); void nf_conntrack_expect_pernet_fini(struct net *net); diff --git a/net/netfilter/nf_conntrack_helper.c b/net/netfilter/nf_conntrack_helper.c index 6dc44d9b4190..752a977e9eef 100644 --- a/net/netfilter/nf_conntrack_helper.c +++ b/net/netfilter/nf_conntrack_helper.c @@ -385,6 +385,9 @@ int nf_conntrack_helper_register(struct nf_conntrack_helper *me) BUG_ON(me->expect_class_max >= NF_CT_MAX_EXPECT_CLASSES); BUG_ON(strlen(me->name) > NF_CT_HELPER_NAME_LEN - 1); + if (me->expect_policy->max_expected > NF_CT_EXPECT_MAX_CNT) + return -EINVAL; + mutex_lock(&nf_ct_helper_mutex); hlist_for_each_entry(cur, &nf_ct_helper_hash[h], hnode) { if (nf_ct_tuple_src_mask_cmp(&cur->tuple, &me->tuple, &mask)) { diff --git a/net/netfilter/nf_conntrack_irc.c b/net/netfilter/nf_conntrack_irc.c index 1972a149f958..1a5af4d4af2d 100644 --- a/net/netfilter/nf_conntrack_irc.c +++ b/net/netfilter/nf_conntrack_irc.c @@ -243,6 +243,12 @@ static int __init nf_conntrack_irc_init(void) return -EINVAL; } + if (max_dcc_channels > NF_CT_EXPECT_MAX_CNT) { + pr_err("max_dcc_channels must not be more than %u\n", + NF_CT_EXPECT_MAX_CNT); + return -EINVAL; + } + irc_exp_policy.max_expected = max_dcc_channels; irc_exp_policy.timeout = dcc_timeout; diff --git a/net/netfilter/nfnetlink_cthelper.c b/net/netfilter/nfnetlink_cthelper.c index d45558178da5..d5025cc25df3 100644 --- a/net/netfilter/nfnetlink_cthelper.c +++ b/net/netfilter/nfnetlink_cthelper.c @@ -150,6 +150,9 @@ nfnl_cthelper_expect_policy(struct nf_conntrack_expect_policy *expect_policy, nla_data(tb[NFCTH_POLICY_NAME]), NF_CT_HELPER_NAME_LEN); expect_policy->max_expected = ntohl(nla_get_be32(tb[NFCTH_POLICY_EXPECT_MAX])); + if (expect_policy->max_expected > NF_CT_EXPECT_MAX_CNT) + return -EINVAL; + expect_policy->timeout = ntohl(nla_get_be32(tb[NFCTH_POLICY_EXPECT_TIMEOUT])); @@ -290,6 +293,9 @@ nfnl_cthelper_update_policy_one(const struct nf_conntrack_expect_policy *policy, new_policy->max_expected = ntohl(nla_get_be32(tb[NFCTH_POLICY_EXPECT_MAX])); + if (new_policy->max_expected > NF_CT_EXPECT_MAX_CNT) + return -EINVAL; + new_policy->timeout = ntohl(nla_get_be32(tb[NFCTH_POLICY_EXPECT_TIMEOUT])); -- 2.20.1