net: Fix ns_capable check in sock_diag_put_filterinfo

[ Upstream commit 78541c1dc60b65ecfce5a6a096fc260219d6784e ]

The caller needs capabilities on the namespace being queried, not on
their own namespace.  This is a security bug, although it likely has
only a minor impact.

Cc: stable@vger.kernel.org
Signed-off-by: Andy Lutomirski <luto@amacapital.net>
Acked-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff --git a/include/linux/sock_diag.h b/include/linux/sock_diag.h
index 54f91d3..302ab80 100644
--- a/include/linux/sock_diag.h
+++ b/include/linux/sock_diag.h
@@ -23,7 +23,7 @@
 void sock_diag_save_cookie(void *sk, __u32 *cookie);
 
 int sock_diag_put_meminfo(struct sock *sk, struct sk_buff *skb, int attr);
-int sock_diag_put_filterinfo(struct user_namespace *user_ns, struct sock *sk,
+int sock_diag_put_filterinfo(struct sock *sk,
 			     struct sk_buff *skb, int attrtype);
 
 #endif