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Date:   Tue, 20 Sep 2022 10:32:02 -0700
From:   Dan Williams <dan.j.williams@intel.com>
To:     Bo Liu <liubo03@inspur.com>, <dan.j.williams@intel.com>,
        <vishal.l.verma@intel.com>, <dave.jiang@intel.com>,
        <ira.weiny@intel.com>
CC:     <nvdimm@lists.linux.dev>, <linux-kernel@vger.kernel.org>,
        Bo Liu <liubo03@inspur.com>
Subject: RE: [PATCH] nvdimm: Call ida_simple_remove() when failed
Message-ID: <6329f91293668_2a6ded2948c@dwillia2-xfh.jf.intel.com.notmuch>
References: <20220810060737.5087-1-liubo03@inspur.com>
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Bo Liu wrote:
> In function nvdimm_bus_register(), when code execution fails, we should
> call ida_simple_remove() to free ida.
> 
> Signed-off-by: Bo Liu <liubo03@inspur.com>
> ---
>  drivers/nvdimm/bus.c | 1 +
>  1 file changed, 1 insertion(+)
> 
> diff --git a/drivers/nvdimm/bus.c b/drivers/nvdimm/bus.c
> index b38d0355b0ac..3415dc62632b 100644
> --- a/drivers/nvdimm/bus.c
> +++ b/drivers/nvdimm/bus.c
> @@ -371,6 +371,7 @@ struct nvdimm_bus *nvdimm_bus_register(struct device *parent,
>  	return nvdimm_bus;
>   err:
>  	put_device(&nvdimm_bus->dev);
> +	ida_simple_remove(&nd_ida, nvdimm_bus->id);

No, this is a double-free. The put_device() will trigger
nvdimm_bus_release().