diff --git a/include/linux/netlink.h b/include/linux/netlink.h
index 60e7137f840d..8d2a8924705c 100644
--- a/include/linux/netlink.h
+++ b/include/linux/netlink.h
@@ -62,15 +62,22 @@ netlink_kernel_create(struct net *net, int unit, struct netlink_kernel_cfg *cfg)
 	return __netlink_kernel_create(net, unit, THIS_MODULE, cfg);
 }
 
+/* this can be increased when necessary - don't expose to userland */
+#define NETLINK_MAX_COOKIE_LEN	20
+
 /**
  * struct netlink_ext_ack - netlink extended ACK report struct
  * @_msg: message string to report - don't access directly, use
  *	%NL_SET_ERR_MSG
  * @bad_attr: attribute with error
+ * @cookie: cookie data to return to userspace (for success)
+ * @cookie_len: actual cookie data length
  */
 struct netlink_ext_ack {
 	const char *_msg;
 	const struct nlattr *bad_attr;
+	u8 cookie[NETLINK_MAX_COOKIE_LEN];
+	u8 cookie_len;
 };
 
 /* Always use this macro, this allows later putting the
diff --git a/include/uapi/linux/netlink.h b/include/uapi/linux/netlink.h
index 7df88770e029..f86127a46cfc 100644
--- a/include/uapi/linux/netlink.h
+++ b/include/uapi/linux/netlink.h
@@ -122,6 +122,9 @@ struct nlmsgerr {
  * @NLMSGERR_ATTR_MSG: error message string (string)
  * @NLMSGERR_ATTR_OFFS: offset of the invalid attribute in the original
  *	 message, counting from the beginning of the header (u32)
+ * @NLMSGERR_ATTR_COOKIE: arbitrary subsystem specific cookie to
+ *	be used - in the success case - to identify a created
+ *	object or operation or similar (binary)
  * @__NLMSGERR_ATTR_MAX: number of attributes
  * @NLMSGERR_ATTR_MAX: highest attribute number
  */
@@ -129,6 +132,7 @@ enum nlmsgerr_attrs {
 	NLMSGERR_ATTR_UNUSED,
 	NLMSGERR_ATTR_MSG,
 	NLMSGERR_ATTR_OFFS,
+	NLMSGERR_ATTR_COOKIE,
 
 	__NLMSGERR_ATTR_MAX,
 	NLMSGERR_ATTR_MAX = __NLMSGERR_ATTR_MAX - 1
diff --git a/net/netlink/af_netlink.c b/net/netlink/af_netlink.c
index c1564768000e..ee841f00a6ec 100644
--- a/net/netlink/af_netlink.c
+++ b/net/netlink/af_netlink.c
@@ -2311,6 +2311,10 @@ void netlink_ack(struct sk_buff *in_skb, struct nlmsghdr *nlh, int err,
 		}
 	} else {
 		flags |= NLM_F_CAPPED;
+
+		if (nlk->flags & NETLINK_F_EXT_ACK &&
+		    extack && extack->cookie_len)
+			tlvlen += nla_total_size(extack->cookie_len);
 	}
 
 	if (tlvlen)
@@ -2337,17 +2341,24 @@ void netlink_ack(struct sk_buff *in_skb, struct nlmsghdr *nlh, int err,
 	errmsg->error = err;
 	memcpy(&errmsg->msg, nlh, payload > sizeof(*errmsg) ? nlh->nlmsg_len : sizeof(*nlh));
 
-	if (err && nlk->flags & NETLINK_F_EXT_ACK && extack) {
-		if (extack->_msg)
-			WARN_ON(nla_put_string(skb, NLMSGERR_ATTR_MSG,
-					       extack->_msg));
-		if (extack->bad_attr &&
-		    !WARN_ON((u8 *)extack->bad_attr < in_skb->data ||
-			     (u8 *)extack->bad_attr >= in_skb->data +
-						       in_skb->len))
-			WARN_ON(nla_put_u32(skb, NLMSGERR_ATTR_OFFS,
-					    (u8 *)extack->bad_attr -
-					    in_skb->data));
+	if (nlk->flags & NETLINK_F_EXT_ACK && extack) {
+		if (err) {
+			if (extack->_msg)
+				WARN_ON(nla_put_string(skb, NLMSGERR_ATTR_MSG,
+						       extack->_msg));
+			if (extack->bad_attr &&
+			    !WARN_ON((u8 *)extack->bad_attr < in_skb->data ||
+				     (u8 *)extack->bad_attr >= in_skb->data +
+							       in_skb->len))
+				WARN_ON(nla_put_u32(skb, NLMSGERR_ATTR_OFFS,
+						    (u8 *)extack->bad_attr -
+						    in_skb->data));
+		} else {
+			if (extack->cookie_len)
+				WARN_ON(nla_put(skb, NLMSGERR_ATTR_COOKIE,
+						extack->cookie_len,
+						extack->cookie));
+		}
 	}
 
 	nlmsg_end(skb, rep);