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authorBartosz Golaszewski <brgl@bgdev.pl>2017-06-09 14:41:25 +0300
committerLinus Walleij <linus.walleij@linaro.org>2017-06-20 10:18:33 +0300
commit6f9b3e776d171636ccafbcb39a8210b4fa37136b (patch)
tree7a600dde36983da45a92aa5c1bfe573652e9647d /drivers/gpio/gpio-mockup.c
parentb6730b20837e7402292d35d3cb910fff4dac7099 (diff)
downloadlinux-6f9b3e776d171636ccafbcb39a8210b4fa37136b.tar.xz
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 <brgl@bgdev.pl> Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Diffstat (limited to 'drivers/gpio/gpio-mockup.c')
-rw-r--r--drivers/gpio/gpio-mockup.c19
1 files 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);