Re: [PATCH] firmware: tegra: switch over to memdup_user()

[Michał Mirosław <mirq-linux@xxxxxxxxxxxx>]

On Mon, Oct 18, 2021 at 12:59:40AM -0700, Qing Wang wrote:
[...]
> --- a/drivers/firmware/tegra/bpmp-debugfs.c
> +++ b/drivers/firmware/tegra/bpmp-debugfs.c
> @@ -376,18 +376,11 @@ static ssize_t bpmp_debug_store(struct file *file, const char __user *buf,
>  	if (!filename)
>  		return -ENOENT;
>  
> -	databuf = kmalloc(count, GFP_KERNEL);
> -	if (!databuf)
> -		return -ENOMEM;
> -
> -	if (copy_from_user(databuf, buf, count)) {
> -		err = -EFAULT;
> -		goto free_ret;
> -	}
> +	databuf = memdup_user(buf, count);
> +	if (IS_ERR(databuf))
> +		return ERR_PTR(PTR_ERR(databuf));

ERR_PTR() is too much here.

Best Regards
Michał Mirosław