selinux: add a skb_owned_by() hook
Commit 90ba9b1986b5ac (tcp: tcp_make_synack() can use alloc_skb())
broke certain SELinux/NetLabel configurations by no longer correctly
assigning the sock to the outgoing SYNACK packet.
Cost of atomic operations on the LISTEN socket is quite big,
and we would like it to happen only if really needed.
This patch introduces a new security_ops->skb_owned_by() method,
that is a void operation unless selinux is active.
Reported-by: Miroslav Vadkerti <mvadkert@redhat.com>
Diagnosed-by: Paul Moore <pmoore@redhat.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: linux-security-module@vger.kernel.org
Acked-by: James Morris <james.l.morris@oracle.com>
Tested-by: Paul Moore <pmoore@redhat.com>
Acked-by: Paul Moore <pmoore@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/security/capability.c b/security/capability.c
index 5797750..6783c3e 100644
--- a/security/capability.c
+++ b/security/capability.c
@@ -737,6 +737,11 @@
{
return 0;
}
+
+static void cap_skb_owned_by(struct sk_buff *skb, struct sock *sk)
+{
+}
+
#endif /* CONFIG_SECURITY_NETWORK */
#ifdef CONFIG_SECURITY_NETWORK_XFRM
@@ -1071,6 +1076,7 @@
set_to_cap_if_null(ops, tun_dev_open);
set_to_cap_if_null(ops, tun_dev_attach_queue);
set_to_cap_if_null(ops, tun_dev_attach);
+ set_to_cap_if_null(ops, skb_owned_by);
#endif /* CONFIG_SECURITY_NETWORK */
#ifdef CONFIG_SECURITY_NETWORK_XFRM
set_to_cap_if_null(ops, xfrm_policy_alloc_security);