Re: [Patch] hdac_sysfs: Fix a memory leaking bug in sound/hda/hdac_sysfs.c file of Linux 5.1

From: Takashi Iwai
Date: Thu May 16 2019 - 04:51:41 EST


On Thu, 16 May 2019 10:40:03 +0200,
Gen Zhang wrote:
>
> tree->root and tree->nodes are allocated by memory allocation
> functions. And tree is also an allocated memory. When allocation of
> tree->root and tree->nodes fails, not freeing tree will leak memory.
> Thus we should free tree in this situation.

No, the leftover is freed in the caller side by calling
widget_tree_free().


thanks,

Takashi

>
> Signed-off-by: Gen Zhang <blackgod016574@xxxxxxxxx>
>
> ---
> diff --git a/sound/hda/hdac_sysfs.c b/sound/hda/hdac_sysfs.c
> index fb2aa34..5d8a939 100644
> --- a/sound/hda/hdac_sysfs.c
> +++ b/sound/hda/hdac_sysfs.c
> @@ -370,12 +370,12 @@ static int widget_tree_create(struct hdac_device *codec)
>
> tree->root = kobject_create_and_add("widgets", &codec->dev.kobj);
> if (!tree->root)
> - return -ENOMEM;
> + goto free_tree;
>
> tree->nodes = kcalloc(codec->num_nodes + 1, sizeof(*tree->nodes),
> GFP_KERNEL);
> if (!tree->nodes)
> - return -ENOMEM;
> + goto free_tree;
>
> for (i = 0, nid = codec->start_nid; i < codec->num_nodes; i++, nid++) {
> err = add_widget_node(tree->root, nid, &widget_node_group,
> @@ -393,6 +393,9 @@ static int widget_tree_create(struct hdac_device *codec)
>
> kobject_uevent(tree->root, KOBJ_CHANGE);
> return 0;
> +free_tree:
> + kfree(tree);
> + return -ENOMEM;
> }
>
> int hda_widget_sysfs_init(struct hdac_device *codec)
> ---
>