| Message ID | 20190726091436.8866-1-baijiaju1990@gmail.com (mailing list archive) |
|---|---|
| State | Superseded |
| Headers | show |
| Series | [v2] input: touchscreen: wm97xx-core: Fix possible null-pointer dereferences in wm97xx_ts_input_open() | expand |
On Fri, Jul 26, 2019 at 05:14:36PM +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 at the beginning of > 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> > --- > v2: > * Add a new check of wm->mach_ops in wm97xx_init_pen_irq(). > Thank Charles for helpful advice. > > --- > drivers/input/touchscreen/wm97xx-core.c | 3 +++ > 1 file changed, 3 insertions(+) > > diff --git a/drivers/input/touchscreen/wm97xx-core.c b/drivers/input/touchscreen/wm97xx-core.c > index 0a174bd82915..50b016abf492 100644 > --- a/drivers/input/touchscreen/wm97xx-core.c > +++ b/drivers/input/touchscreen/wm97xx-core.c > @@ -374,6 +374,9 @@ static int wm97xx_init_pen_irq(struct wm97xx *wm) > { > u16 reg; > > + if (!wm->mach_ops) > + return -EINVAL; > + Probably worth adding an printk in here too, the calling function doesn't check the return value of this function so otherwise there will be no indication this failed. Thanks, Charles > /* If an interrupt is supplied an IRQ enable operation must also be > * provided. */ > BUG_ON(!wm->mach_ops->irq_enable); > -- > 2.17.0 >
diff --git a/drivers/input/touchscreen/wm97xx-core.c b/drivers/input/touchscreen/wm97xx-core.c index 0a174bd82915..50b016abf492 100644 --- a/drivers/input/touchscreen/wm97xx-core.c +++ b/drivers/input/touchscreen/wm97xx-core.c @@ -374,6 +374,9 @@ static int wm97xx_init_pen_irq(struct wm97xx *wm) { u16 reg; + if (!wm->mach_ops) + return -EINVAL; + /* If an interrupt is supplied an IRQ enable operation must also be * provided. */ BUG_ON(!wm->mach_ops->irq_enable);
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 at the beginning of 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> --- v2: * Add a new check of wm->mach_ops in wm97xx_init_pen_irq(). Thank Charles for helpful advice. --- drivers/input/touchscreen/wm97xx-core.c | 3 +++ 1 file changed, 3 insertions(+)