On Wed, Mar 20, 2019 at 10:29:16AM +0800, Lin Yi wrote: > write_parport_ref_nonblock increase mos_parport refcount without > decrease it when return -ENOMEM code, so need a decrement before function > return -ENOMEM. Good catch! Your patch looks good, but wouldn't it be better to move the kref_get() (and mos_parport assignment) to the end of the urbtrack initialisation instead? That way you wouldn't have to add any kref_puts() at all. > Signed-off-by: Lin Yi <teroincn@xxxxxxx> > --- > drivers/usb/serial/mos7720.c | 2 ++ > 1 file changed, 2 insertions(+) > > diff --git a/drivers/usb/serial/mos7720.c b/drivers/usb/serial/mos7720.c > index fc52ac7..6abb335 100644 > --- a/drivers/usb/serial/mos7720.c > +++ b/drivers/usb/serial/mos7720.c > @@ -371,12 +371,14 @@ static int write_parport_reg_nonblock(struct mos7715_parport *mos_parport, > urbtrack->urb = usb_alloc_urb(0, GFP_ATOMIC); > if (!urbtrack->urb) { > kfree(urbtrack); > + kref_put(&mos_parport->ref_count, destroy_mos_parport); > return -ENOMEM; > } > urbtrack->setup = kmalloc(sizeof(*urbtrack->setup), GFP_ATOMIC); > if (!urbtrack->setup) { > usb_free_urb(urbtrack->urb); > kfree(urbtrack); > + kref_put(&mos_parport->ref_count, destroy_mos_parport); > return -ENOMEM; > } > urbtrack->setup->bRequestType = (__u8)0x40; Thanks, Johan