Messages in this thread Patch in this message | | | From | Radim Pavlik <> | Subject | [PATCH] sc16is7xx: Prevent dereferencing invalid data when gpio_hog used | Date | Fri, 17 Dec 2021 16:06:48 +0100 |
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gpio_hog is trying to use gpio functions during probe call. At that time we dont have initialized port data which are dereferenced via assigned gpio.direction_input/output functions. This results in unable to handle kernel NULL pointer dereference followed by Kernel panic. This patch prevents that.
Signed-off-by: Radim Pavlik <radim.pavlik@tbs-biometrics.com> --- drivers/tty/serial/sc16is7xx.c | 38 +++++++++++++++++----------------- 1 file changed, 19 insertions(+), 19 deletions(-)
diff --git a/drivers/tty/serial/sc16is7xx.c b/drivers/tty/serial/sc16is7xx.c index 64e7e6c8145f..9f4c5d64fb10 100644 --- a/drivers/tty/serial/sc16is7xx.c +++ b/drivers/tty/serial/sc16is7xx.c @@ -1242,25 +1242,6 @@ static int sc16is7xx_probe(struct device *dev, } sched_set_fifo(s->kworker_task);
-#ifdef CONFIG_GPIOLIB - if (devtype->nr_gpio) { - /* Setup GPIO cotroller */ - s->gpio.owner = THIS_MODULE; - s->gpio.parent = dev; - s->gpio.label = dev_name(dev); - s->gpio.direction_input = sc16is7xx_gpio_direction_input; - s->gpio.get = sc16is7xx_gpio_get; - s->gpio.direction_output = sc16is7xx_gpio_direction_output; - s->gpio.set = sc16is7xx_gpio_set; - s->gpio.base = -1; - s->gpio.ngpio = devtype->nr_gpio; - s->gpio.can_sleep = 1; - ret = gpiochip_add_data(&s->gpio, s); - if (ret) - goto out_thread; - } -#endif - /* reset device, purging any pending irq / data */ regmap_write(s->regmap, SC16IS7XX_IOCONTROL_REG << SC16IS7XX_REG_SHIFT, SC16IS7XX_IOCONTROL_SRESET_BIT); @@ -1315,6 +1296,25 @@ static int sc16is7xx_probe(struct device *dev, sc16is7xx_power(&s->p[i].port, 0); }
+#ifdef CONFIG_GPIOLIB + if (devtype->nr_gpio) { + /* Setup GPIO cotroller */ + s->gpio.owner = THIS_MODULE; + s->gpio.parent = dev; + s->gpio.label = dev_name(dev); + s->gpio.direction_input = sc16is7xx_gpio_direction_input; + s->gpio.get = sc16is7xx_gpio_get; + s->gpio.direction_output = sc16is7xx_gpio_direction_output; + s->gpio.set = sc16is7xx_gpio_set; + s->gpio.base = -1; + s->gpio.ngpio = devtype->nr_gpio; + s->gpio.can_sleep = 1; + ret = gpiochip_add_data(&s->gpio, s); + if (ret) + goto out_thread; + } +#endif + if (dev->of_node) { struct property *prop; const __be32 *p; -- 2.32.0
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