decnet: fix shutdown parameter checking

The allowed value of "how" is SHUT_RD/SHUT_WR/SHUT_RDWR (0/1/2),
rather than SHUTDOWN_MASK (3).

Signed-off-by: Xi Wang <xi.wang@gmail.com>
Acked-by: Steven Whitehouse <swhiteho@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 2 insertions, 2 deletions

diff --git a/net/decnet/af_decnet.c b/net/decnet/af_decnet.c
index 2ba1a2814c24..307c322d53bb 100644
--- a/net/decnet/af_decnet.c
+++ b/net/decnet/af_decnet.c
@@ -1313,10 +1313,10 @@ static int dn_shutdown(struct socket *sock, int how)
         if (scp->state == DN_O)
                 goto out;
 
-        if (how != SHUTDOWN_MASK)
+        if (how != SHUT_RDWR)
                 goto out;
 
-        sk->sk_shutdown = how;
+        sk->sk_shutdown = SHUTDOWN_MASK;
         dn_destroy_sock(sk);
         err = 0;