Re: [PATCH] pps: add an error check in parport_attach

[Greg KH <gregkh@linuxfoundation.org>]

On Tue, Aug 13, 2024 at 11:08:00AM +0800, Ma Ke wrote:
> In parport_attach, the return value of ida_alloc is unchecked, witch leads
> to the use of an invalid index value.
> 
> To address this issue, index should be checked. When the index value is
> abnormal, the device should be freed.
> 
> Found by code review, compile tested only.
> 
> Cc: stable@vger.kernel.org
> Fixes: 55dbc5b5174d ("pps: remove usage of the deprecated ida_simple_xx() API")
> Signed-off-by: Ma Ke <make24@iscas.ac.cn>
> ---
>  drivers/pps/clients/pps_parport.c | 10 ++++++++--
>  1 file changed, 8 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/pps/clients/pps_parport.c b/drivers/pps/clients/pps_parport.c
> index 63d03a0df5cc..9ab7f6961e42 100644
> --- a/drivers/pps/clients/pps_parport.c
> +++ b/drivers/pps/clients/pps_parport.c
> @@ -149,6 +149,11 @@ static void parport_attach(struct parport *port)
>  	}
>  
>  	index = ida_alloc(&pps_client_index, GFP_KERNEL);
> +	if (index < 0) {
> +		pr_err("failed to get index\n");

No need to be noisy, right?

thanks,

greg k-h