xfrm: add rcu protection to sk->sk_policy[]

[linux-drm-fsl-dcu.git] / net / xfrm / xfrm_policy.c

diff --git a/net/xfrm/xfrm_policy.c b/net/xfrm/xfrm_policy.c
index f57a5712cedd1db8c4f53fca06fa4ae274e5892a..948fa5560de500a8634835c24fa666b37a1ea33b 100644 (file)
--- a/net/xfrm/xfrm_policy.c
+++ b/net/xfrm/xfrm_policy.c
@@ -1221,8 +1221,10 @@ static struct xfrm_policy *xfrm_sk_policy_lookup(const struct sock *sk, int dir,
        struct xfrm_policy *pol;
        struct net *net = sock_net(sk);
 
+       rcu_read_lock();
        read_lock_bh(&net->xfrm.xfrm_policy_lock);
-       if ((pol = sk->sk_policy[dir]) != NULL) {
+       pol = rcu_dereference(sk->sk_policy[dir]);
+       if (pol != NULL) {
                bool match = xfrm_selector_match(&pol->selector, fl,
                                                 sk->sk_family);
                int err = 0;
@@ -1246,6 +1248,7 @@ static struct xfrm_policy *xfrm_sk_policy_lookup(const struct sock *sk, int dir,
        }
 out:
        read_unlock_bh(&net->xfrm.xfrm_policy_lock);
+       rcu_read_unlock();
        return pol;
 }
 
@@ -1314,13 +1317,14 @@ int xfrm_sk_policy_insert(struct sock *sk, int dir, struct xfrm_policy *pol)
 #endif
 
        write_lock_bh(&net->xfrm.xfrm_policy_lock);
-       old_pol = sk->sk_policy[dir];
-       sk->sk_policy[dir] = pol;
+       old_pol = rcu_dereference_protected(sk->sk_policy[dir],
+                               lockdep_is_held(&net->xfrm.xfrm_policy_lock));
        if (pol) {
                pol->curlft.add_time = get_seconds();
                pol->index = xfrm_gen_index(net, XFRM_POLICY_MAX+dir, 0);
                xfrm_sk_policy_link(pol, dir);
        }
+       rcu_assign_pointer(sk->sk_policy[dir], pol);
        if (old_pol) {
                if (pol)
                        xfrm_policy_requeue(old_pol, pol);
@@ -1368,17 +1372,26 @@ static struct xfrm_policy *clone_policy(const struct xfrm_policy *old, int dir)
        return newp;
 }
 
-int __xfrm_sk_clone_policy(struct sock *sk)
+int __xfrm_sk_clone_policy(struct sock *sk, const struct sock *osk)
 {
-       struct xfrm_policy *p0 = sk->sk_policy[0],
-                          *p1 = sk->sk_policy[1];
+       const struct xfrm_policy *p;
+       struct xfrm_policy *np;
+       int i, ret = 0;
 
-       sk->sk_policy[0] = sk->sk_policy[1] = NULL;
-       if (p0 && (sk->sk_policy[0] = clone_policy(p0, 0)) == NULL)
-               return -ENOMEM;
-       if (p1 && (sk->sk_policy[1] = clone_policy(p1, 1)) == NULL)
-               return -ENOMEM;
-       return 0;
+       rcu_read_lock();
+       for (i = 0; i < 2; i++) {
+               p = rcu_dereference(osk->sk_policy[i]);
+               if (p) {
+                       np = clone_policy(p, i);
+                       if (unlikely(!np)) {
+                               ret = -ENOMEM;
+                               break;
+                       }
+                       rcu_assign_pointer(sk->sk_policy[i], np);
+               }
+       }
+       rcu_read_unlock();
+       return ret;
 }
 
 static int