Re: [PATCH] i2c: core: Fix possible memleak in i2c_new_client_device()

Wolfram Sang
2021-10-17T15:27:23Z

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> In error path after calling i2c_dev_set_name(), the put_device()
> should be used to give up the device reference, then the name
> allocated in dev_set_name() will be freed in kobject_cleanup().

I don't see it. dev_set_name does not call device_get, so why should we
call device_put on failure? No other user of dev_set_name seems to do
this. So, if this is an imbalance, where does the unmatched get_device
really come from?

>
> Reported-by: Hulk Robot <hulkci@huawei.com>
> Signed-off-by: Yang Yingliang <yangyingliang@huawei.com>
> ---
> drivers/i2c/i2c-core-base.c | 13 +++++++------
> 1 file changed, 7 insertions(+), 6 deletions(-)
>
> diff --git a/drivers/i2c/i2c-core-base.c b/drivers/i2c/i2c-core-base.c
> index 54964fbe3f03..190d4fd5e594 100644
> --- a/drivers/i2c/i2c-core-base.c
> +++ b/drivers/i2c/i2c-core-base.c
> @@ -1047,8 +1047,6 @@ i2c_new_client_device(struct i2c_adapter *adap, struct i2c_board_info const *inf
> client->dev.of_node = of_node_get(info->of_node);
> client->dev.fwnode = info->fwnode;
>
> - i2c_dev_set_name(adap, client, info);
> -
> if (info->swnode) {
> status = device_add_software_node(&client->dev, info->swnode);
> if (status) {
> @@ -1059,17 +1057,20 @@ i2c_new_client_device(struct i2c_adapter *adap, struct i2c_board_info const *inf
> }
> }
>
> + i2c_dev_set_name(adap, client, info);
> status = device_register(&client->dev);
> - if (status)
> - goto out_remove_swnode;
> + if (status) {
> + device_remove_software_node(&client->dev);
> + of_node_put(info->of_node);
> + put_device(&client->dev);
> + return ERR_PTR(status);
> + }
>
> dev_dbg(&adap->dev, "client [%s] registered with bus id %s\n",
> client->name, dev_name(&client->dev));
>
> return client;
>
> -out_remove_swnode:
> - device_remove_software_node(&client->dev);
> out_err_put_of_node:
> of_node_put(info->of_node);
> out_err:
> --
> 2.25.1
>

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