diff --git a/net/xfrm/xfrm_input.c b/net/xfrm/xfrm_input.c
index 526c4feb3b50d723d24b8c55288c8c941257da52..459796a78ab02e4ca42448251214d5bfdbeef5c9 100644
--- a/net/xfrm/xfrm_input.c
+++ b/net/xfrm/xfrm_input.c
@@ -29,7 +29,7 @@ int xfrm_input_register_afinfo(struct xfrm_input_afinfo *afinfo)
 		return -EAFNOSUPPORT;
 	spin_lock_bh(&xfrm_input_afinfo_lock);
 	if (unlikely(xfrm_input_afinfo[afinfo->family] != NULL))
-		err = -ENOBUFS;
+		err = -EEXIST;
 	else
 		rcu_assign_pointer(xfrm_input_afinfo[afinfo->family], afinfo);
 	spin_unlock_bh(&xfrm_input_afinfo_lock);
diff --git a/net/xfrm/xfrm_policy.c b/net/xfrm/xfrm_policy.c
index 847053ec7d91dcd8c38b49c1b25ea17a0277379e..c4c47f337a3a04b7bf6762834850b462d143fc0c 100644
--- a/net/xfrm/xfrm_policy.c
+++ b/net/xfrm/xfrm_policy.c
@@ -2808,7 +2808,7 @@ int xfrm_policy_register_afinfo(struct xfrm_policy_afinfo *afinfo)
 		return -EAFNOSUPPORT;
 	spin_lock(&xfrm_policy_afinfo_lock);
 	if (unlikely(xfrm_policy_afinfo[afinfo->family] != NULL))
-		err = -ENOBUFS;
+		err = -EEXIST;
 	else {
 		struct dst_ops *dst_ops = afinfo->dst_ops;
 		if (likely(dst_ops->kmem_cachep == NULL))
diff --git a/net/xfrm/xfrm_state.c b/net/xfrm/xfrm_state.c
index df9318301e981af5dc5742e8658fb6609ecc529c..e47e4980b35c8dee0fcf474355c3f4e2f09c389f 100644
--- a/net/xfrm/xfrm_state.c
+++ b/net/xfrm/xfrm_state.c
@@ -1908,7 +1908,7 @@ int xfrm_state_register_afinfo(struct xfrm_state_afinfo *afinfo)
 		return -EAFNOSUPPORT;
 	spin_lock_bh(&xfrm_state_afinfo_lock);
 	if (unlikely(xfrm_state_afinfo[afinfo->family] != NULL))
-		err = -ENOBUFS;
+		err = -EEXIST;
 	else
 		rcu_assign_pointer(xfrm_state_afinfo[afinfo->family], afinfo);
 	spin_unlock_bh(&xfrm_state_afinfo_lock);