From 6f9b3e776d171636ccafbcb39a8210b4fa37136b Mon Sep 17 00:00:00 2001 From: Bartosz Golaszewski Date: Fri, 9 Jun 2017 13:41:25 +0200 Subject: gpio: mockup: improve the debugfs input sanitization We're currently only checking the first character of the input to the debugfs event files, so a string like '0sdfdsf' is valid and indicates a falling edge event. Be more strict and only allow '0', '1', '0\n' & '1\n'. While we're at it: move the sanitization code before the irq_enabled check so that we indicate an error on invalid input even if nobody is waiting for events. Signed-off-by: Bartosz Golaszewski Reviewed-by: Andy Shevchenko Signed-off-by: Linus Walleij --- drivers/gpio/gpio-mockup.c | 19 +++++++------------ 1 file changed, 7 insertions(+), 12 deletions(-) diff --git a/drivers/gpio/gpio-mockup.c b/drivers/gpio/gpio-mockup.c index ba8d62aa801a..da76267aa85c 100644 --- a/drivers/gpio/gpio-mockup.c +++ b/drivers/gpio/gpio-mockup.c @@ -208,8 +208,7 @@ static ssize_t gpio_mockup_event_write(struct file *file, struct seq_file *sfile; struct gpio_desc *desc; struct gpio_chip *gc; - int val; - char buf; + int rv, val; sfile = file->private_data; priv = sfile->private; @@ -217,19 +216,15 @@ static ssize_t gpio_mockup_event_write(struct file *file, chip = priv->chip; gc = &chip->gc; + rv = kstrtoint_from_user(usr_buf, size, 0, &val); + if (rv) + return rv; + if (val != 0 && val != 1) + return -EINVAL; + if (!chip->lines[priv->offset].irq_enabled) return size; - if (copy_from_user(&buf, usr_buf, 1)) - return -EFAULT; - - if (buf == '0') - val = 0; - else if (buf == '1') - val = 1; - else - return -EINVAL; - gpiod_set_value_cansleep(desc, val); priv->chip->irq_ctx.irq = gc->irq_base + priv->offset; irq_work_queue(&priv->chip->irq_ctx.work); -- cgit v1.2.3