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'.
Signed-off-by: Bartosz Golaszewski <b...@bgdev.pl>
---
drivers/gpio/gpio-mockup.c | 14 ++++++++++----
1 file changed, 10 insertions(+), 4 deletions(-)
diff --git a/drivers/gpio/gpio-mockup.c b/drivers/gpio/gpio-mockup.c
index ba8d62a..b197b93 100644
--- a/drivers/gpio/gpio-mockup.c
+++ b/drivers/gpio/gpio-mockup.c
@@ -208,8 +208,8 @@ static ssize_t gpio_mockup_event_write(struct file *file,
struct seq_file *sfile;
struct gpio_desc *desc;
struct gpio_chip *gc;
+ char buf[2];
int val;
- char buf;
sfile = file->private_data;
priv = sfile->private;
@@ -220,12 +220,18 @@ static ssize_t gpio_mockup_event_write(struct file *file,
if (!chip->lines[priv->offset].irq_enabled)
return size;
- if (copy_from_user(&buf, usr_buf, 1))
+ if (size > 2)
+ return -EINVAL;
+
+ if (copy_from_user(&buf, usr_buf, 2))
return -EFAULT;
- if (buf == '0')
+ if (size == 2 && buf[1] != '\n')
+ return -EINVAL;
+
+ if (buf[0] == '0')
val = 0;
- else if (buf == '1')
+ else if (buf[0] == '1')
val = 1;
else
return -EINVAL;
--
2.9.3
