diff --git a/net/xfrm/xfrm_user.c b/net/xfrm/xfrm_user.c
index d41e5642625e..3d0fdeebaf3c 100644
--- a/net/xfrm/xfrm_user.c
+++ b/net/xfrm/xfrm_user.c
@@ -893,8 +893,11 @@ static struct xfrm_state *xfrm_state_construct(struct net *net,
 
 	if (attrs[XFRMA_SA_PCPU]) {
 		x->pcpu_num = nla_get_u32(attrs[XFRMA_SA_PCPU]);
-		if (x->pcpu_num >= num_possible_cpus())
+		if (x->pcpu_num >= num_possible_cpus()) {
+			err = -ERANGE;
+			NL_SET_ERR_MSG(extack, "pCPU number too big");
 			goto error;
+		}
 	}
 
 	err = __xfrm_init_state(x, false, attrs[XFRMA_OFFLOAD_DEV], extack);