[NETFILTER]: Fix unbalanced read_unlock_bh in ctnetlink

NFA_NEST calls NFA_PUT which jumps to nfattr_failure if the skb has no
room left. We call read_unlock_bh at nfattr_failure for the NFA_PUT inside
the locked section, so move NFA_NEST inside the locked section too.

Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 2 insertions, 1 deletions

diff --git a/net/ipv4/netfilter/ip_conntrack_proto_tcp.c b/net/ipv4/netfilter/ip_conntrack_proto_tcp.c
index aeb7353d4777..e7fa29e576dc 100644
--- a/net/ipv4/netfilter/ip_conntrack_proto_tcp.c
+++ b/net/ipv4/netfilter/ip_conntrack_proto_tcp.c
@@ -341,9 +341,10 @@ static int tcp_print_conntrack(struct seq_file *s,
 static int tcp_to_nfattr(struct sk_buff *skb, struct nfattr *nfa,
                          const struct ip_conntrack *ct)
 {
-        struct nfattr *nest_parms = NFA_NEST(skb, CTA_PROTOINFO_TCP);
+        struct nfattr *nest_parms;
         
         read_lock_bh(&tcp_lock);
+        nest_parms = NFA_NEST(skb, CTA_PROTOINFO_TCP);
         NFA_PUT(skb, CTA_PROTOINFO_TCP_STATE, sizeof(u_int8_t),
                 &ct->proto.tcp.state);
         read_unlock_bh(&tcp_lock);