Dan Carpenter points out that deref occurs after NULL check, we should re-fetch the pointer and check that instead. Fixes: 2c205dd3981f7 ("netfilter: add struct nf_nat_hook and use it") Reported-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx> Signed-off-by: Florian Westphal <fw@xxxxxxxxx> --- Not even compile tested, patch is vs. nf-next as nf.git doesn't contain the problematic change yet. diff --git a/net/netfilter/nf_conntrack_netlink.c b/net/netfilter/nf_conntrack_netlink.c index 39327a42879f..20a2e37c76d1 100644 --- a/net/netfilter/nf_conntrack_netlink.c +++ b/net/netfilter/nf_conntrack_netlink.c @@ -1446,7 +1446,8 @@ ctnetlink_parse_nat_setup(struct nf_conn *ct, } nfnl_lock(NFNL_SUBSYS_CTNETLINK); rcu_read_lock(); - if (nat_hook->parse_nat_setup) + nat_hook = rcu_dereference(nf_nat_hook); + if (nat_hook) return -EAGAIN; #endif return -EOPNOTSUPP; -- 2.17.1 -- To unsubscribe from this list: send the line "unsubscribe netfilter-devel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html