Re: [PATCH] media: pvrusb2: fix null-ptr-deref in class_unregister()

[isely]

Acked-By: Mike Isely <isely@xxxxxxxxx>

On Wed, 5 Jun 2019, Kefeng Wang wrote:

> The class_ptr will be NULL if pvr2_sysfs_class_create() fails
> in pvr_init(), when call pvr2_sysfs_class_destroy(), it will
> lead to null-ptr-deref, fix it.
> 
> Reported-by: Hulk Robot <hulkci@xxxxxxxxxx>
> Signed-off-by: Kefeng Wang <wangkefeng.wang@xxxxxxxxxx>
> ---
>  drivers/media/usb/pvrusb2/pvrusb2-sysfs.c | 3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/media/usb/pvrusb2/pvrusb2-sysfs.c b/drivers/media/usb/pvrusb2/pvrusb2-sysfs.c
> index 7bc6d090358e..b6c6b314fadc 100644
> --- a/drivers/media/usb/pvrusb2/pvrusb2-sysfs.c
> +++ b/drivers/media/usb/pvrusb2/pvrusb2-sysfs.c
> @@ -802,7 +802,8 @@ struct pvr2_sysfs_class *pvr2_sysfs_class_create(void)
>  void pvr2_sysfs_class_destroy(struct pvr2_sysfs_class *clp)
>  {
>  	pvr2_sysfs_trace("Unregistering pvr2_sysfs_class id=%p", clp);
> -	class_unregister(&clp->class);
> +	if (clp)
> +		class_unregister(&clp->class);
>  }
>  
>  
> 

-- 

Mike Isely
isely @ isely (dot) net
PGP: 03 54 43 4D 75 E5 CC 92 71 16 01 E2 B5 F5 C1 E8