From 75c689dca98851d65ef5a27e5ce26b625b68751c Mon Sep 17 00:00:00 2001 From: Gao Feng Date: Sat, 25 Mar 2017 18:24:36 +0800 Subject: [PATCH] netfilter: nf_nat_snmp: Fix panic when snmp_trap_helper fails to register In the commit 93557f53e1fb ("netfilter: nf_conntrack: nf_conntrack snmp helper"), the snmp_helper is replaced by nf_nat_snmp_hook. So the snmp_helper is never registered. But it still tries to unregister the snmp_helper, it could cause the panic. Now remove the useless snmp_helper and the unregister call in the error handler. Fixes: 93557f53e1fb ("netfilter: nf_conntrack: nf_conntrack snmp helper") Signed-off-by: Gao Feng Signed-off-by: Pablo Neira Ayuso --- net/ipv4/netfilter/nf_nat_snmp_basic.c | 19 +------------------ 1 file changed, 1 insertion(+), 18 deletions(-) diff --git a/net/ipv4/netfilter/nf_nat_snmp_basic.c b/net/ipv4/netfilter/nf_nat_snmp_basic.c index 5a8f7c360887..53e49f5011d3 100644 --- a/net/ipv4/netfilter/nf_nat_snmp_basic.c +++ b/net/ipv4/netfilter/nf_nat_snmp_basic.c @@ -1260,16 +1260,6 @@ static const struct nf_conntrack_expect_policy snmp_exp_policy = { .timeout = 180, }; -static struct nf_conntrack_helper snmp_helper __read_mostly = { - .me = THIS_MODULE, - .help = help, - .expect_policy = &snmp_exp_policy, - .name = "snmp", - .tuple.src.l3num = AF_INET, - .tuple.src.u.udp.port = cpu_to_be16(SNMP_PORT), - .tuple.dst.protonum = IPPROTO_UDP, -}; - static struct nf_conntrack_helper snmp_trap_helper __read_mostly = { .me = THIS_MODULE, .help = help, @@ -1288,17 +1278,10 @@ static struct nf_conntrack_helper snmp_trap_helper __read_mostly = { static int __init nf_nat_snmp_basic_init(void) { - int ret = 0; - BUG_ON(nf_nat_snmp_hook != NULL); RCU_INIT_POINTER(nf_nat_snmp_hook, help); - ret = nf_conntrack_helper_register(&snmp_trap_helper); - if (ret < 0) { - nf_conntrack_helper_unregister(&snmp_helper); - return ret; - } - return ret; + return nf_conntrack_helper_register(&snmp_trap_helper); } static void __exit nf_nat_snmp_basic_fini(void) -- 2.20.1