Re: [PATCH] soc: mpfs: use kref cleanup on probe failure

[Felix Gu]

Hi Guangshuo,

On Thu, Sep 24, 2026 at 7:01 PM Guangshuo Li <lgs201920130244@xxxxxxxxx> wrote:
>
> After kref_init(), the device_get_match_data() failure path jumps to
> out_free_channel. That path frees the mailbox channel and then falls
> through to kfree(), bypassing mpfs_sys_controller_put() for the initial
> reference.
>
> Call mpfs_sys_controller_put() on that path and return immediately. The
> existing kref release callback then performs the matching cleanup, and
> the return prevents a second free through out_free. This is the minimal
> change needed to keep the initialized lifetime balanced.
>

I don't think this is a fix.  mpfs_sys_controller_put() does the same
mbox_free_channel() + kfree() the current path already does.

> Fixes: 75ef23397558 ("soc: microchip: mpfs-sys-controller: fix resource leak on probe error")
> ---
>  drivers/soc/microchip/mpfs-sys-controller.c | 3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/soc/microchip/mpfs-sys-controller.c b/drivers/soc/microchip/mpfs-sys-controller.c
> index 0400a01b2338..379e4f649faa 100644
> --- a/drivers/soc/microchip/mpfs-sys-controller.c
> +++ b/drivers/soc/microchip/mpfs-sys-controller.c
> @@ -174,7 +174,8 @@ static int mpfs_sys_controller_probe(struct platform_device *pdev)
>         return 0;
>
>  out_free_channel:
> -       mbox_free_channel(sys_controller->chan);
> +       mpfs_sys_controller_put(sys_controller);
> +       return ret;

If you do keep this, the out_free_channel label no longer fits.

Thanks,
Felix