virtio_net: Allocate rss_hdr with devres

virtnet_probe() lacks the code to free rss_hdr in its error path.
Allocate rss_hdr with devres so that it will be automatically freed.

Fixes: 86a48a0 ("virtio_net: Support dynamic rss indirection table size")
Signed-off-by: Akihiko Odaki <akihiko.odaki@daynix.com>
Acked-by: Jason Wang <jasowang@redhat.com>
Reviewed-by: Xuan Zhuo <xuanzhuo@linux.alibaba.com>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
Tested-by: Lei Yang <leiyang@redhat.com>
Link: https://patch.msgid.link/20250321-virtio-v2-4-33afb8f4640b@daynix.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

drivers/net/virtio_net.c

@@ -3642,7 +3642,7 @@ static int virtnet_set_queues(struct virtnet_info *vi, u16 queue_pairs)
 	if (vi->has_rss && !netif_is_rxfh_configured(dev)) {
 		old_rss_hdr = vi->rss_hdr;
 		old_rss_trailer = vi->rss_trailer;
-		vi->rss_hdr = kzalloc(virtnet_rss_hdr_size(vi), GFP_KERNEL);
+		vi->rss_hdr = devm_kzalloc(&dev->dev, virtnet_rss_hdr_size(vi), GFP_KERNEL);
 		if (!vi->rss_hdr) {
 			vi->rss_hdr = old_rss_hdr;
 			return -ENOMEM;
@@ -3653,15 +3653,15 @@ static int virtnet_set_queues(struct virtnet_info *vi, u16 queue_pairs)
 
 		if (!virtnet_commit_rss_command(vi)) {
 			/* restore ctrl_rss if commit_rss_command failed */
-			kfree(vi->rss_hdr);
+			devm_kfree(&dev->dev, vi->rss_hdr);
 			vi->rss_hdr = old_rss_hdr;
 			vi->rss_trailer = old_rss_trailer;
 
 			dev_warn(&dev->dev, "Fail to set num of queue pairs to %d, because committing RSS failed\n",
 				 queue_pairs);
 			return -EINVAL;
 		}
-		kfree(old_rss_hdr);
+		devm_kfree(&dev->dev, old_rss_hdr);
 		goto succ;
 	}
 
@@ -6768,7 +6768,7 @@ static int virtnet_probe(struct virtio_device *vdev)
 			virtio_cread16(vdev, offsetof(struct virtio_net_config,
 				rss_max_indirection_table_length));
 	}
-	vi->rss_hdr = kzalloc(virtnet_rss_hdr_size(vi), GFP_KERNEL);
+	vi->rss_hdr = devm_kzalloc(&vdev->dev, virtnet_rss_hdr_size(vi), GFP_KERNEL);
 	if (!vi->rss_hdr) {
 		err = -ENOMEM;
 		goto free;
@@ -7051,8 +7051,6 @@ static void virtnet_remove(struct virtio_device *vdev)
 
 	remove_vq_common(vi);
 
-	kfree(vi->rss_hdr);
-
 	free_netdev(vi->dev);
 }