| Message ID | 20190726084816.8487-1-baijiaju1990@gmail.com (mailing list archive) |
|---|---|
| State | Superseded |
| Headers | show |
| Series | input: touchscreen: wm97xx-core: Fix possible null-pointer dereferences in wm97xx_ts_input_open() | expand |
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@gmail.com> > --- > 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 >
On 2019/7/26 17:06, Charles Keepax wrote: > 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@gmail.com> >> --- >> 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 for the advice. I will send a v2 patch of adding a new check in wm97xx_init_pen_irq(). Best wishes, Jia-Ju Bai
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");
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@gmail.com> --- drivers/input/touchscreen/wm97xx-core.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)