diff --git a/net/wireless/nl80211.c b/net/wireless/nl80211.c
index ba439664c2e0..4d708cea390f 100644
--- a/net/wireless/nl80211.c
+++ b/net/wireless/nl80211.c
@@ -47,22 +47,21 @@ static struct genl_family nl80211_fam = {
 };
 
 /* internal helper: get rdev and dev */
-static int get_rdev_dev_by_info_ifindex(struct genl_info *info,
-				       struct cfg80211_registered_device **rdev,
-				       struct net_device **dev)
+static int get_rdev_dev_by_ifindex(struct net *netns, struct nlattr **attrs,
+				   struct cfg80211_registered_device **rdev,
+				   struct net_device **dev)
 {
-	struct nlattr **attrs = info->attrs;
 	int ifindex;
 
 	if (!attrs[NL80211_ATTR_IFINDEX])
 		return -EINVAL;
 
 	ifindex = nla_get_u32(attrs[NL80211_ATTR_IFINDEX]);
-	*dev = dev_get_by_index(genl_info_net(info), ifindex);
+	*dev = dev_get_by_index(netns, ifindex);
 	if (!*dev)
 		return -ENODEV;
 
-	*rdev = cfg80211_get_dev_from_ifindex(genl_info_net(info), ifindex);
+	*rdev = cfg80211_get_dev_from_ifindex(netns, ifindex);
 	if (IS_ERR(*rdev)) {
 		dev_put(*dev);
 		return PTR_ERR(*rdev);
@@ -4795,7 +4794,7 @@ static int nl80211_testmode_do(struct sk_buff *skb, struct genl_info *info)
 static int nl80211_testmode_dump(struct sk_buff *skb,
 				 struct netlink_callback *cb)
 {
-	struct cfg80211_registered_device *dev;
+	struct cfg80211_registered_device *rdev;
 	int err;
 	long phy_idx;
 	void *data = NULL;
@@ -4813,9 +4812,21 @@ static int nl80211_testmode_dump(struct sk_buff *skb,
 				  nl80211_policy);
 		if (err)
 			return err;
-		if (!nl80211_fam.attrbuf[NL80211_ATTR_WIPHY])
-			return -EINVAL;
-		phy_idx = nla_get_u32(nl80211_fam.attrbuf[NL80211_ATTR_WIPHY]);
+		if (nl80211_fam.attrbuf[NL80211_ATTR_WIPHY]) {
+			phy_idx = nla_get_u32(
+				nl80211_fam.attrbuf[NL80211_ATTR_WIPHY]);
+		} else {
+			struct net_device *netdev;
+
+			err = get_rdev_dev_by_ifindex(sock_net(skb->sk),
+						      nl80211_fam.attrbuf,
+						      &rdev, &netdev);
+			if (err)
+				return err;
+			dev_put(netdev);
+			phy_idx = rdev->wiphy_idx;
+			cfg80211_unlock_rdev(rdev);
+		}
 		if (nl80211_fam.attrbuf[NL80211_ATTR_TESTDATA])
 			cb->args[1] =
 				(long)nl80211_fam.attrbuf[NL80211_ATTR_TESTDATA];
@@ -4827,15 +4838,15 @@ static int nl80211_testmode_dump(struct sk_buff *skb,
 	}
 
 	mutex_lock(&cfg80211_mutex);
-	dev = cfg80211_rdev_by_wiphy_idx(phy_idx);
-	if (!dev) {
+	rdev = cfg80211_rdev_by_wiphy_idx(phy_idx);
+	if (!rdev) {
 		mutex_unlock(&cfg80211_mutex);
 		return -ENOENT;
 	}
-	cfg80211_lock_rdev(dev);
+	cfg80211_lock_rdev(rdev);
 	mutex_unlock(&cfg80211_mutex);
 
-	if (!dev->ops->testmode_dump) {
+	if (!rdev->ops->testmode_dump) {
 		err = -EOPNOTSUPP;
 		goto out_err;
 	}
@@ -4846,7 +4857,7 @@ static int nl80211_testmode_dump(struct sk_buff *skb,
 					   NL80211_CMD_TESTMODE);
 		struct nlattr *tmdata;
 
-		if (nla_put_u32(skb, NL80211_ATTR_WIPHY, dev->wiphy_idx) < 0) {
+		if (nla_put_u32(skb, NL80211_ATTR_WIPHY, phy_idx) < 0) {
 			genlmsg_cancel(skb, hdr);
 			break;
 		}
@@ -4856,8 +4867,8 @@ static int nl80211_testmode_dump(struct sk_buff *skb,
 			genlmsg_cancel(skb, hdr);
 			break;
 		}
-		err = dev->ops->testmode_dump(&dev->wiphy, skb, cb,
-					      data, data_len);
+		err = rdev->ops->testmode_dump(&rdev->wiphy, skb, cb,
+					       data, data_len);
 		nla_nest_end(skb, tmdata);
 
 		if (err == -ENOBUFS || err == -ENOENT) {
@@ -4875,7 +4886,7 @@ static int nl80211_testmode_dump(struct sk_buff *skb,
 	/* see above */
 	cb->args[0] = phy_idx + 1;
  out_err:
-	cfg80211_unlock_rdev(dev);
+	cfg80211_unlock_rdev(rdev);
 	return err;
 }
 
@@ -6110,7 +6121,8 @@ static int nl80211_pre_doit(struct genl_ops *ops, struct sk_buff *skb,
 		}
 		info->user_ptr[0] = rdev;
 	} else if (ops->internal_flags & NL80211_FLAG_NEED_NETDEV) {
-		err = get_rdev_dev_by_info_ifindex(info, &rdev, &dev);
+		err = get_rdev_dev_by_ifindex(genl_info_net(info), info->attrs,
+					      &rdev, &dev);
 		if (err) {
 			if (rtnl)
 				rtnl_unlock();