[NETFILTER] NAT: Fix module refcount dropping too far
The unknown protocol is used as a fallback when a protocol isn't known.
Hence we cannot handle it failing, so don't set ".me". It's OK, since we
only grab a reference from within the same module (iptable_nat.ko), so we
never take the module refcount from 0 to 1.
Also, remove the "protocol is NULL" test: it's never NULL.
Signed-off-by: Rusty Rusty <rusty@rustcorp.com.au>
Signed-off-by: Harald Welte <laforge@netfilter.org>
Signed-off-by: Arnaldo Carvalho de Melo <acme@mandriva.com>
diff --git a/net/ipv4/netfilter/ip_nat_core.c b/net/ipv4/netfilter/ip_nat_core.c
index c5e3abd..762f4d9 100644
--- a/net/ipv4/netfilter/ip_nat_core.c
+++ b/net/ipv4/netfilter/ip_nat_core.c
@@ -66,10 +66,8 @@
* removed until we've grabbed the reference */
preempt_disable();
p = __ip_nat_proto_find(protonum);
- if (p) {
- if (!try_module_get(p->me))
- p = &ip_nat_unknown_protocol;
- }
+ if (!try_module_get(p->me))
+ p = &ip_nat_unknown_protocol;
preempt_enable();
return p;
diff --git a/net/ipv4/netfilter/ip_nat_proto_unknown.c b/net/ipv4/netfilter/ip_nat_proto_unknown.c
index 99bbef5..f0099a6 100644
--- a/net/ipv4/netfilter/ip_nat_proto_unknown.c
+++ b/net/ipv4/netfilter/ip_nat_proto_unknown.c
@@ -62,7 +62,7 @@
struct ip_nat_protocol ip_nat_unknown_protocol = {
.name = "unknown",
- .me = THIS_MODULE,
+ /* .me isn't set: getting a ref to this cannot fail. */
.manip_pkt = unknown_manip_pkt,
.in_range = unknown_in_range,
.unique_tuple = unknown_unique_tuple,