xfrm: Add SA to hardware at the end of xfrm_state_construct()

Current code configures the hardware with a new SA before the state has been
fully initialized. During this time interval, an incoming ESP packet can cause
a crash due to a NULL dereference. More specifically, xfrm_input() considers
the packet as valid, and yet, anti-replay mechanism is not initialized.

Move hardware configuration to the end of xfrm_state_construct(), and mark
the state as valid once the SA is fully initialized.

Fixes: d77e38e612a0 ("xfrm: Add an IPsec hardware offloading API")
Signed-off-by: Aviad Yehezkel <aviadye@mellnaox.com>
Signed-off-by: Aviv Heller <avivh@mellanox.com>
Signed-off-by: Yossi Kuperman <yossiku@mellanox.com>
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>

2 files changed, 18 insertions, 10 deletions

diff --git a/net/xfrm/xfrm_state.c b/net/xfrm/xfrm_state.c
index 429957412633..2d486492acdb 100644
--- a/net/xfrm/xfrm_state.c
+++ b/net/xfrm/xfrm_state.c
@@ -2272,8 +2272,6 @@ int __xfrm_init_state(struct xfrm_state *x, bool init_replay, bool offload)
                         goto error;
         }
 
-        x->km.state = XFRM_STATE_VALID;
-
 error:
         return err;
 }
@@ -2282,7 +2280,13 @@ EXPORT_SYMBOL(__xfrm_init_state);
 
 int xfrm_init_state(struct xfrm_state *x)
 {
-        return __xfrm_init_state(x, true, false);
+        int err;
+
+        err = __xfrm_init_state(x, true, false);
+        if (!err)
+                x->km.state = XFRM_STATE_VALID;
+
+        return err;
 }
 
 EXPORT_SYMBOL(xfrm_init_state);
diff --git a/net/xfrm/xfrm_user.c b/net/xfrm/xfrm_user.c
index bdb48e5dba04..7f52b8eb177d 100644
--- a/net/xfrm/xfrm_user.c
+++ b/net/xfrm/xfrm_user.c
@@ -598,13 +598,6 @@ static struct xfrm_state *xfrm_state_construct(struct net *net,
                         goto error;
         }
 
-        if (attrs[XFRMA_OFFLOAD_DEV]) {
-                err = xfrm_dev_state_add(net, x,
-                                         nla_data(attrs[XFRMA_OFFLOAD_DEV]));
-                if (err)
-                        goto error;
-        }
-
         if ((err = xfrm_alloc_replay_state_esn(&x->replay_esn, &x->preplay_esn,
                                                attrs[XFRMA_REPLAY_ESN_VAL])))
                 goto error;
@@ -620,6 +613,14 @@ static struct xfrm_state *xfrm_state_construct(struct net *net,
         /* override default values from above */
         xfrm_update_ae_params(x, attrs, 0);
 
+        /* configure the hardware if offload is requested */
+        if (attrs[XFRMA_OFFLOAD_DEV]) {
+                err = xfrm_dev_state_add(net, x,
+                                         nla_data(attrs[XFRMA_OFFLOAD_DEV]));
+                if (err)
+                        goto error;
+        }
+
         return x;
 
 error:
@@ -662,6 +663,9 @@ static int xfrm_add_sa(struct sk_buff *skb, struct nlmsghdr *nlh,
                 goto out;
         }
 
+        if (x->km.state == XFRM_STATE_VOID)
+                x->km.state = XFRM_STATE_VALID;
+
         c.seq = nlh->nlmsg_seq;
         c.portid = nlh->nlmsg_pid;
         c.event = nlh->nlmsg_type;