diff --git a/net/netfilter/nf_conntrack_netlink.c b/net/netfilter/nf_conntrack_netlink.c index 06d28ac663df4f4061fa380fde47a89efaea6529..f9c643bc1a8e2ff1de2c2775a2ef0bc2147c6cb3 100644 --- a/net/netfilter/nf_conntrack_netlink.c +++ b/net/netfilter/nf_conntrack_netlink.c @@ -1488,11 +1488,16 @@ static int ctnetlink_change_helper(struct nf_conn *ct, * treat the second attempt as a no-op instead of returning * an error. */ - if (help && help->helper && - !strcmp(help->helper->name, helpname)) - return 0; - else - return -EBUSY; + err = -EBUSY; + if (help) { + rcu_read_lock(); + helper = rcu_dereference(help->helper); + if (helper && !strcmp(helper->name, helpname)) + err = 0; + rcu_read_unlock(); + } + + return err; } if (!strcmp(helpname, "")) {