The helper registration return value is passed-through by module_init callbacks which modprobe confuses with the harmless -EEXIST returned when trying to load an already loaded module.
Make sure modprobe fails so users notice their helper has not been registered and won't work. Suggested-by: Christophe Leroy <christophe.le...@csgroup.eu> Fixes: 12f7a505331e ("netfilter: add user-space connection tracking helper infrastructure") Signed-off-by: Phil Sutter <p...@nwl.cc> --- net/netfilter/nf_conntrack_helper.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/net/netfilter/nf_conntrack_helper.c b/net/netfilter/nf_conntrack_helper.c index 4ed5878cb25b..ceb48c3ca0a4 100644 --- a/net/netfilter/nf_conntrack_helper.c +++ b/net/netfilter/nf_conntrack_helper.c @@ -368,7 +368,7 @@ int nf_conntrack_helper_register(struct nf_conntrack_helper *me) (cur->tuple.src.l3num == NFPROTO_UNSPEC || cur->tuple.src.l3num == me->tuple.src.l3num) && cur->tuple.dst.protonum == me->tuple.dst.protonum) { - ret = -EEXIST; + ret = -EBUSY; goto out; } } @@ -379,7 +379,7 @@ int nf_conntrack_helper_register(struct nf_conntrack_helper *me) hlist_for_each_entry(cur, &nf_ct_helper_hash[h], hnode) { if (nf_ct_tuple_src_mask_cmp(&cur->tuple, &me->tuple, &mask)) { - ret = -EEXIST; + ret = -EBUSY; goto out; } } -- 2.49.0