On Fri, Jul 26, 2019 at 04:48:16PM +0800, Jia-Ju Bai wrote: > In wm97xx_ts_input_open(), there is an if statement on line 507 to check > whether wm->mach_ops is NULL: > if (wm->mach_ops && wm->mach_ops->acc_enabled) > > When wm->mach_ops is NULL, it is used on line 521: > wm97xx_init_pen_irq(wm); > BUG_ON(!wm->mach_ops->irq_enable); > BUG_ON(!wm->mach_ops->irq_gpio); > wm97xx_reg_write(..., reg & ~(wm->mach_ops->irq_gpio)) > > Thus, possible null-pointer dereferences may occur. > > To fix these bugs, wm->mach_ops is checked before calling > wm97xx_init_pen_irq(). > > These bugs found by a static analysis tool STCheck written by us. > > Signed-off-by: Jia-Ju Bai <baijiaju1990@xxxxxxxxx> > --- > drivers/input/touchscreen/wm97xx-core.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/drivers/input/touchscreen/wm97xx-core.c b/drivers/input/touchscreen/wm97xx-core.c > index 0a174bd82915..f7bd0726a577 100644 > --- a/drivers/input/touchscreen/wm97xx-core.c > +++ b/drivers/input/touchscreen/wm97xx-core.c > @@ -517,7 +517,7 @@ static int wm97xx_ts_input_open(struct input_dev *idev) > wm->ts_reader_interval = wm->ts_reader_min_interval; > > wm->pen_is_down = 0; > - if (wm->pen_irq) > + if (wm->pen_irq && wm->mach_ops) > wm97xx_init_pen_irq(wm); > else > dev_err(wm->dev, "No IRQ specified\n"); This doesn't quite feel like the right fix as it would print an error message saying "No IRQ specified", in the case the IRQ is specified but the mach_ops have not been set. I would suggest either extending the existing BUG_ON or adding a new check in wm97xx_init_pen_irq. Thanks, Charles > -- > 2.17.0 >
