7 files changed, 80 insertions, 14 deletions

diff --git a/include/net/xfrm.h b/include/net/xfrm.h
index 4351444c10fc..8d1c9506bcf6 100644
--- a/include/net/xfrm.h
+++ b/include/net/xfrm.h
@@ -423,7 +423,6 @@ int xfrm_register_type_offload(const struct xfrm_type_offload *type, unsigned sh
 int xfrm_unregister_type_offload(const struct xfrm_type_offload *type, unsigned short family);
 
 struct xfrm_mode {
-        struct xfrm_state_afinfo *afinfo;
         struct module *owner;
         u8 encap;
         u8 family;
diff --git a/net/ipv4/xfrm4_output.c b/net/ipv4/xfrm4_output.c
index 6802d1aee424..7c3df14daef3 100644
--- a/net/ipv4/xfrm4_output.c
+++ b/net/ipv4/xfrm4_output.c
@@ -72,6 +72,8 @@ int xfrm4_output_finish(struct sock *sk, struct sk_buff *skb)
 static int __xfrm4_output(struct net *net, struct sock *sk, struct sk_buff *skb)
 {
         struct xfrm_state *x = skb_dst(skb)->xfrm;
+        const struct xfrm_state_afinfo *afinfo;
+        int ret = -EAFNOSUPPORT;
 
 #ifdef CONFIG_NETFILTER
         if (!x) {
@@ -80,7 +82,15 @@ static int __xfrm4_output(struct net *net, struct sock *sk, struct sk_buff *skb)
         }
 #endif
 
-        return x->outer_mode->afinfo->output_finish(sk, skb);
+        rcu_read_lock();
+        afinfo = xfrm_state_afinfo_get_rcu(x->outer_mode->family);
+        if (likely(afinfo))
+                ret = afinfo->output_finish(sk, skb);
+        else
+                kfree_skb(skb);
+        rcu_read_unlock();
+
+        return ret;
 }
 
 int xfrm4_output(struct net *net, struct sock *sk, struct sk_buff *skb)
diff --git a/net/ipv6/xfrm6_output.c b/net/ipv6/xfrm6_output.c
index 2b663d2ffdcd..455fbf3b91cf 100644
--- a/net/ipv6/xfrm6_output.c
+++ b/net/ipv6/xfrm6_output.c
@@ -122,11 +122,28 @@ int xfrm6_output_finish(struct sock *sk, struct sk_buff *skb)
         return xfrm_output(sk, skb);
 }
 
+static int __xfrm6_output_state_finish(struct xfrm_state *x, struct sock *sk,
+                                       struct sk_buff *skb)
+{
+        const struct xfrm_state_afinfo *afinfo;
+        int ret = -EAFNOSUPPORT;
+
+        rcu_read_lock();
+        afinfo = xfrm_state_afinfo_get_rcu(x->outer_mode->family);
+        if (likely(afinfo))
+                ret = afinfo->output_finish(sk, skb);
+        else
+                kfree_skb(skb);
+        rcu_read_unlock();
+
+        return ret;
+}
+
 static int __xfrm6_output_finish(struct net *net, struct sock *sk, struct sk_buff *skb)
 {
         struct xfrm_state *x = skb_dst(skb)->xfrm;
 
-        return x->outer_mode->afinfo->output_finish(sk, skb);
+        return __xfrm6_output_state_finish(x, sk, skb);
 }
 
 static int __xfrm6_output(struct net *net, struct sock *sk, struct sk_buff *skb)
@@ -168,7 +185,7 @@ static int __xfrm6_output(struct net *net, struct sock *sk, struct sk_buff *skb)
                                     __xfrm6_output_finish);
 
 skip_frag:
-        return x->outer_mode->afinfo->output_finish(sk, skb);
+        return __xfrm6_output_state_finish(x, sk, skb);
 }
 
 int xfrm6_output(struct net *net, struct sock *sk, struct sk_buff *skb)
diff --git a/net/xfrm/xfrm_input.c b/net/xfrm/xfrm_input.c
index e0fd9561ffe5..74b53c13279b 100644
--- a/net/xfrm/xfrm_input.c
+++ b/net/xfrm/xfrm_input.c
@@ -352,19 +352,35 @@ xfrm_inner_mode_encap_remove(struct xfrm_state *x,
 static int xfrm_prepare_input(struct xfrm_state *x, struct sk_buff *skb)
 {
         struct xfrm_mode *inner_mode = x->inner_mode;
-        int err;
+        const struct xfrm_state_afinfo *afinfo;
+        int err = -EAFNOSUPPORT;
 
-        err = x->outer_mode->afinfo->extract_input(x, skb);
-        if (err)
+        rcu_read_lock();
+        afinfo = xfrm_state_afinfo_get_rcu(x->outer_mode->family);
+        if (likely(afinfo))
+                err = afinfo->extract_input(x, skb);
+
+        if (err) {
+                rcu_read_unlock();
                 return err;
+        }
 
         if (x->sel.family == AF_UNSPEC) {
                 inner_mode = xfrm_ip2inner_mode(x, XFRM_MODE_SKB_CB(skb)->protocol);
-                if (inner_mode == NULL)
+                if (!inner_mode) {
+                        rcu_read_unlock();
                         return -EAFNOSUPPORT;
+                }
         }
 
-        skb->protocol = inner_mode->afinfo->eth_proto;
+        afinfo = xfrm_state_afinfo_get_rcu(inner_mode->family);
+        if (unlikely(!afinfo)) {
+                rcu_read_unlock();
+                return -EAFNOSUPPORT;
+        }
+
+        skb->protocol = afinfo->eth_proto;
+        rcu_read_unlock();
         return xfrm_inner_mode_encap_remove(x, inner_mode, skb);
 }
 
@@ -440,6 +456,7 @@ static int xfrm_inner_mode_input(struct xfrm_state *x,
 
 int xfrm_input(struct sk_buff *skb, int nexthdr, __be32 spi, int encap_type)
 {
+        const struct xfrm_state_afinfo *afinfo;
         struct net *net = dev_net(skb->dev);
         int err;
         __be32 seq;
@@ -705,7 +722,12 @@ resume:
                 if (xo)
                         xfrm_gro = xo->flags & XFRM_GRO;
 
-                err = x->inner_mode->afinfo->transport_finish(skb, xfrm_gro || async);
+                err = -EAFNOSUPPORT;
+                rcu_read_lock();
+                afinfo = xfrm_state_afinfo_get_rcu(x->inner_mode->family);
+                if (likely(afinfo))
+                        err = afinfo->transport_finish(skb, xfrm_gro || async);
+                rcu_read_unlock();
                 if (xfrm_gro) {
                         sp = skb_sec_path(skb);
                         if (sp)
diff --git a/net/xfrm/xfrm_output.c b/net/xfrm/xfrm_output.c
index 9bdf16f13606..17c4f58d28ea 100644
--- a/net/xfrm/xfrm_output.c
+++ b/net/xfrm/xfrm_output.c
@@ -623,7 +623,10 @@ EXPORT_SYMBOL_GPL(xfrm_output);
 
 static int xfrm_inner_extract_output(struct xfrm_state *x, struct sk_buff *skb)
 {
+        const struct xfrm_state_afinfo *afinfo;
         struct xfrm_mode *inner_mode;
+        int err = -EAFNOSUPPORT;
+
         if (x->sel.family == AF_UNSPEC)
                 inner_mode = xfrm_ip2inner_mode(x,
                                 xfrm_af2proto(skb_dst(skb)->ops->family));
@@ -632,7 +635,14 @@ static int xfrm_inner_extract_output(struct xfrm_state *x, struct sk_buff *skb)
 
         if (inner_mode == NULL)
                 return -EAFNOSUPPORT;
-        return inner_mode->afinfo->extract_output(x, skb);
+
+        rcu_read_lock();
+        afinfo = xfrm_state_afinfo_get_rcu(inner_mode->family);
+        if (likely(afinfo))
+                err = afinfo->extract_output(x, skb);
+        rcu_read_unlock();
+
+        return err;
 }
 
 void xfrm_local_error(struct sk_buff *skb, int mtu)
diff --git a/net/xfrm/xfrm_policy.c b/net/xfrm/xfrm_policy.c
index 8d1a898d0ba5..67122beb116c 100644
--- a/net/xfrm/xfrm_policy.c
+++ b/net/xfrm/xfrm_policy.c
@@ -2545,6 +2545,7 @@ static struct dst_entry *xfrm_bundle_create(struct xfrm_policy *policy,
                                             const struct flowi *fl,
                                             struct dst_entry *dst)
 {
+        const struct xfrm_state_afinfo *afinfo;
         struct net *net = xp_net(policy);
         unsigned long now = jiffies;
         struct net_device *dev;
@@ -2622,7 +2623,14 @@ static struct dst_entry *xfrm_bundle_create(struct xfrm_policy *policy,
                 dst1->lastuse = now;
 
                 dst1->input = dst_discard;
-                dst1->output = inner_mode->afinfo->output;
+
+                rcu_read_lock();
+                afinfo = xfrm_state_afinfo_get_rcu(inner_mode->family);
+                if (likely(afinfo))
+                        dst1->output = afinfo->output;
+                else
+                        dst1->output = dst_discard_out;
+                rcu_read_unlock();
 
                 xdst_prev = xdst;
 
diff --git a/net/xfrm/xfrm_state.c b/net/xfrm/xfrm_state.c
index c32394b59776..358b09f0d018 100644
--- a/net/xfrm/xfrm_state.c
+++ b/net/xfrm/xfrm_state.c
@@ -354,7 +354,6 @@ int xfrm_register_mode(struct xfrm_mode *mode)
         if (!try_module_get(afinfo->owner))
                 goto out;
 
-        mode->afinfo = afinfo;
         modemap[mode->encap] = mode;
         err = 0;
 
@@ -378,7 +377,7 @@ void xfrm_unregister_mode(struct xfrm_mode *mode)
         spin_lock_bh(&xfrm_mode_lock);
         if (likely(modemap[mode->encap] == mode)) {
                 modemap[mode->encap] = NULL;
-                module_put(mode->afinfo->owner);
+                module_put(afinfo->owner);
         }
 
         spin_unlock_bh(&xfrm_mode_lock);
@@ -2188,6 +2187,7 @@ struct xfrm_state_afinfo *xfrm_state_afinfo_get_rcu(unsigned int family)
 
         return rcu_dereference(xfrm_state_afinfo[family]);
 }
+EXPORT_SYMBOL_GPL(xfrm_state_afinfo_get_rcu);
 
 struct xfrm_state_afinfo *xfrm_state_get_afinfo(unsigned int family)
 {