Re: [PATCH] floppy: fix reference leak on platform_device_register() failure

["Denis Efremov (Oracle)" <efremov@linux.com>]

Hello,

Thank you for the patch,

On 13/04/2026 19:31, Guangshuo Li wrote:
> When platform_device_register() fails in do_floppy_init(), the embedded
> struct device in floppy_device[drive] has already been initialized by
> device_initialize(), but the failure path jumps to out_remove_drives
> without dropping the device reference for the current drive.
> 
> Previously registered floppy devices are cleaned up in out_remove_drives,
> but the device for the drive that fails registration is not, leading to
> a reference leak.
> 
> The issue was identified by a static analysis tool I developed and
> confirmed by manual review. Fix this by calling put_device() for the
> current floppy device before jumping to the common cleanup path.
> 
> Fixes: 94fd0db7bfb4a ("[PATCH] Floppy: Add cmos attribute to floppy driver")
> Cc: stable@vger.kernel.org
> Signed-off-by: Guangshuo Li <lgs201920130244@gmail.com>
> ---
>  drivers/block/floppy.c | 4 +++-
>  1 file changed, 3 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/block/floppy.c b/drivers/block/floppy.c
> index c28786e0fe1c..d9afe495d5c2 100644
> --- a/drivers/block/floppy.c
> +++ b/drivers/block/floppy.c
> @@ -4724,8 +4724,10 @@ static int __init do_floppy_init(void)
>  		floppy_device[drive].dev.groups = floppy_dev_groups;
>  
>  		err = platform_device_register(&floppy_device[drive]);
> -		if (err)
> +		if (err) {
> +			put_device(&floppy_device[drive].dev);

1. Let's use platform_device_put()

>  			goto out_remove_drives;
> +		}
>  
>  		registered[drive] = true;
>  

                err = device_add_disk(&floppy_device[drive].dev,
                                      disks[drive][0], NULL);
                if (err)
                        goto out_remove_drives;

2. We also need to fix this case.

platform_device_unregister()
registered[drive] = false;
goto ...

Thanks,
Denis