[PATCH 3.16 092/178] netfilter: nf_nat_snmp: Fix panic when snmp_trap_helper fails to register
From: Ben Hutchings <hidden>
Date: 2017-07-16 14:03:11
Also in:
lkml
3.16.46-rc1 review patch. If anyone has any objections, please let me know.
------------------
From: Gao Feng <redacted>
commit 75c689dca98851d65ef5a27e5ce26b625b68751c upstream.
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 <redacted>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Ben Hutchings <redacted>
---
net/ipv4/netfilter/nf_nat_snmp_basic.c | 19 +------------------
1 file changed, 1 insertion(+), 18 deletions(-)
--- 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_ .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_t 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)