Re: [PATCH] usb: u132-hcd: fix potential NULL pointer dereference

[Greg Kroah-Hartman]

On Tue, Mar 19, 2019 at 12:34:06PM -0500, Kangjie Lu wrote:
> In case create_singlethread_workqueue fails, the fix notifies
> callers the error to avoid potential NULL pointer dereferences.
> 
> Signed-off-by: Kangjie Lu <kjlu@xxxxxxx>
> ---
> removed "unlikely"
> ---
>  drivers/usb/host/u132-hcd.c | 2 ++
>  1 file changed, 2 insertions(+)
> 
> diff --git a/drivers/usb/host/u132-hcd.c b/drivers/usb/host/u132-hcd.c
> index 934584f0a20a..6d5b532b03f8 100644
> --- a/drivers/usb/host/u132-hcd.c
> +++ b/drivers/usb/host/u132-hcd.c
> @@ -3203,6 +3203,8 @@ static int __init u132_hcd_init(void)
>  		return -ENODEV;
>  	printk(KERN_INFO "driver %s\n", hcd_name);
>  	workqueue = create_singlethread_workqueue("u132");
> +	if (!workqueue)
> +		return -ENOMEM;
>  	retval = platform_driver_register(&u132_platform_driver);
>  	return retval;

if platform_driver_register() fails, shouldn't you clean up the
workqueue?  That can be a separate patch, that's not your fault here :)

thanks,

greg k-h