From 893e093c786c4256d52809eed697e9d70a6f6643 Mon Sep 17 00:00:00 2001 From: Pablo Neira Ayuso Date: Tue, 24 May 2016 11:23:51 +0200 Subject: [PATCH] netfilter: nf_ct_helper: bail out on duplicated helpers Don't allow registration of helpers using the same tuple: { l3proto, l4proto, src-port } We lookup for the helper from the packet path using this tuple through __nf_ct_helper_find(). Therefore, we have to avoid having two helpers with the same tuple to ensure predictible behaviour. Don't compare the helper string names anymore since it is valid to register two helpers with the same name, but using different tuples. This is also implicitly fixing up duplicated helper registration via ports= modparam since the name comparison was defeating the tuple duplication validation. Reported-by: Feng Gao Reported-by: Taehee Yoo Signed-off-by: Pablo Neira Ayuso --- net/netfilter/nf_conntrack_helper.c | 9 ++++----- 1 file changed, 4 insertions(+), 5 deletions(-) diff --git a/net/netfilter/nf_conntrack_helper.c b/net/netfilter/nf_conntrack_helper.c index 3b40ec575cd5..48de9be45a9a 100644 --- a/net/netfilter/nf_conntrack_helper.c +++ b/net/netfilter/nf_conntrack_helper.c @@ -361,9 +361,10 @@ EXPORT_SYMBOL_GPL(nf_ct_helper_log); int nf_conntrack_helper_register(struct nf_conntrack_helper *me) { - int ret = 0; - struct nf_conntrack_helper *cur; + struct nf_conntrack_tuple_mask mask = { .src.u.all = htons(0xFFFF) }; unsigned int h = helper_hash(&me->tuple); + struct nf_conntrack_helper *cur; + int ret = 0; BUG_ON(me->expect_policy == NULL); BUG_ON(me->expect_class_max >= NF_CT_MAX_EXPECT_CLASSES); @@ -371,9 +372,7 @@ int nf_conntrack_helper_register(struct nf_conntrack_helper *me) mutex_lock(&nf_ct_helper_mutex); hlist_for_each_entry(cur, &nf_ct_helper_hash[h], hnode) { - if (strncmp(cur->name, me->name, NF_CT_HELPER_NAME_LEN) == 0 && - cur->tuple.src.l3num == me->tuple.src.l3num && - cur->tuple.dst.protonum == me->tuple.dst.protonum) { + if (nf_ct_tuple_src_mask_cmp(&cur->tuple, &me->tuple, &mask)) { ret = -EEXIST; goto out; } -- 2.20.1