[IPSEC]: Lock state when copying non-atomic fields to user-space

This patch adds locking so that when we're copying non-atomic fields such as
life-time or coaddr to user-space we don't get a partial result.

For af_key I've changed every instance of pfkey_xfrm_state2msg apart from
expiration notification to include the keys and life-times.  This is in-line
with XFRM behaviour.

The actual cases affected are:

* pfkey_getspi: No change as we don't have any keys to copy.
* key_notify_sa:
	+ ADD/UPD: This wouldn't work otherwise.
	+ DEL: It can't hurt.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 8 insertions, 6 deletions

diff --git a/net/xfrm/xfrm_user.c b/net/xfrm/xfrm_user.c
index 2cbbe5e93a7..5238f6a8dfa 100644
--- a/net/xfrm/xfrm_user.c
+++ b/net/xfrm/xfrm_user.c
@@ -507,8 +507,16 @@ static int copy_to_user_state_extra(struct xfrm_state *x,
                                     struct xfrm_usersa_info *p,
                                     struct sk_buff *skb)
 {
+        spin_lock_bh(&x->lock);
         copy_to_user_state(x, p);
 
+        if (x->coaddr)
+                NLA_PUT(skb, XFRMA_COADDR, sizeof(*x->coaddr), x->coaddr);
+
+        if (x->lastused)
+                NLA_PUT_U64(skb, XFRMA_LASTUSED, x->lastused);
+        spin_unlock_bh(&x->lock);
+
         if (x->aalg)
                 NLA_PUT(skb, XFRMA_ALG_AUTH, alg_len(x->aalg), x->aalg);
         if (x->ealg)
@@ -522,12 +530,6 @@ static int copy_to_user_state_extra(struct xfrm_state *x,
         if (x->security && copy_sec_ctx(x->security, skb) < 0)
                 goto nla_put_failure;
 
-        if (x->coaddr)
-                NLA_PUT(skb, XFRMA_COADDR, sizeof(*x->coaddr), x->coaddr);
-
-        if (x->lastused)
-                NLA_PUT_U64(skb, XFRMA_LASTUSED, x->lastused);
-
         return 0;
 
 nla_put_failure: