diff --git a/net/netfilter/nf_conntrack_netlink.c b/net/netfilter/nf_conntrack_netlink.c index aa1a97ee514b..d6d39e241327 100644 --- a/net/netfilter/nf_conntrack_netlink.c +++ b/net/netfilter/nf_conntrack_netlink.c @@ -830,11 +830,6 @@ ctnetlink_change_helper(struct nf_conn *ct, struct nfattr *cda[]) char *helpname; int err; - if (!help) { - /* FIXME: we need to reallocate and rehash */ - return -EBUSY; - } - /* don't change helper of sibling connections */ if (ct->master) return -EINVAL; @@ -843,25 +838,34 @@ ctnetlink_change_helper(struct nf_conn *ct, struct nfattr *cda[]) if (err < 0) return err; - helper = __nf_conntrack_helper_find_byname(helpname); - if (!helper) { - if (!strcmp(helpname, "")) - helper = NULL; - else - return -EINVAL; - } - - if (help->helper) { - if (!helper) { + if (!strcmp(helpname, "")) { + if (help && help->helper) { /* we had a helper before ... */ nf_ct_remove_expectations(ct); help->helper = NULL; - } else { - /* need to zero data of old helper */ - memset(&help->help, 0, sizeof(help->help)); } + + return 0; } + if (!help) { + /* FIXME: we need to reallocate and rehash */ + return -EBUSY; + } + + helper = __nf_conntrack_helper_find_byname(helpname); + if (helper == NULL) + return -EINVAL; + + if (help->helper == helper) + return 0; + + if (help->helper) + /* we had a helper before ... */ + nf_ct_remove_expectations(ct); + + /* need to zero data of old helper */ + memset(&help->help, 0, sizeof(help->help)); help->helper = helper; return 0;