diff --git a/include/linux/xfrm.h b/include/linux/xfrm.h
index 22e61fdf75a2..28e493b5b94c 100644
--- a/include/linux/xfrm.h
+++ b/include/linux/xfrm.h
@@ -84,6 +84,8 @@ struct xfrm_replay_state {
 	__u32	bitmap;
 };
 
+#define XFRMA_REPLAY_ESN_MAX	4096
+
 struct xfrm_replay_state_esn {
 	unsigned int	bmp_len;
 	__u32		oseq;
diff --git a/net/xfrm/xfrm_user.c b/net/xfrm/xfrm_user.c
index 8024b3dea8c2..5927065e97cf 100644
--- a/net/xfrm/xfrm_user.c
+++ b/net/xfrm/xfrm_user.c
@@ -123,9 +123,21 @@ static inline int verify_replay(struct xfrm_usersa_info *p,
 				struct nlattr **attrs)
 {
 	struct nlattr *rt = attrs[XFRMA_REPLAY_ESN_VAL];
+	struct xfrm_replay_state_esn *rs;
 
-	if ((p->flags & XFRM_STATE_ESN) && !rt)
-		return -EINVAL;
+	if (p->flags & XFRM_STATE_ESN) {
+		if (!rt)
+			return -EINVAL;
+
+		rs = nla_data(rt);
+
+		if (rs->bmp_len > XFRMA_REPLAY_ESN_MAX / sizeof(rs->bmp[0]) / 8)
+			return -EINVAL;
+
+		if (nla_len(rt) < xfrm_replay_state_esn_len(rs) &&
+		    nla_len(rt) != sizeof(*rs))
+			return -EINVAL;
+	}
 
 	if (!rt)
 		return 0;
@@ -370,14 +382,15 @@ static inline int xfrm_replay_verify_len(struct xfrm_replay_state_esn *replay_es
 					 struct nlattr *rp)
 {
 	struct xfrm_replay_state_esn *up;
+	int ulen;
 
 	if (!replay_esn || !rp)
 		return 0;
 
 	up = nla_data(rp);
+	ulen = xfrm_replay_state_esn_len(up);
 
-	if (xfrm_replay_state_esn_len(replay_esn) !=
-			xfrm_replay_state_esn_len(up))
+	if (nla_len(rp) < ulen || xfrm_replay_state_esn_len(replay_esn) != ulen)
 		return -EINVAL;
 
 	return 0;
@@ -388,22 +401,28 @@ static int xfrm_alloc_replay_state_esn(struct xfrm_replay_state_esn **replay_esn
 				       struct nlattr *rta)
 {
 	struct xfrm_replay_state_esn *p, *pp, *up;
+	int klen, ulen;
 
 	if (!rta)
 		return 0;
 
 	up = nla_data(rta);
+	klen = xfrm_replay_state_esn_len(up);
+	ulen = nla_len(rta) >= klen ? klen : sizeof(*up);
 
-	p = kmemdup(up, xfrm_replay_state_esn_len(up), GFP_KERNEL);
+	p = kzalloc(klen, GFP_KERNEL);
 	if (!p)
 		return -ENOMEM;
 
-	pp = kmemdup(up, xfrm_replay_state_esn_len(up), GFP_KERNEL);
+	pp = kzalloc(klen, GFP_KERNEL);
 	if (!pp) {
 		kfree(p);
 		return -ENOMEM;
 	}
 
+	memcpy(p, up, ulen);
+	memcpy(pp, up, ulen);
+
 	*replay_esn = p;
 	*preplay_esn = pp;