uleds_read() copies the current brightness value to userspace but
ignores copy_to_user() failures. It then clears the pending update and
reports a successful full read even when no data was copied.
Return -EFAULT when the copy fails and leave the update pending so a
later read can retry.
Signed-off-by: Yousef Alhouseen <alhouseenyousef@gmail.com>
---
drivers/leds/uleds.c | 11 +++++++----
1 file changed, 7 insertions(+), 4 deletions(-)
diff --git a/drivers/leds/uleds.c b/drivers/leds/uleds.c
index ace71ffc0591..470015e3f802 100644
--- a/drivers/leds/uleds.c
+++ b/drivers/leds/uleds.c
@@ -147,10 +147,13 @@ static ssize_t uleds_read(struct file *file, char __user *buffer, size_t count,
} else if (!udev->new_data && (file->f_flags & O_NONBLOCK)) {
retval = -EAGAIN;
} else if (udev->new_data) {
- retval = copy_to_user(buffer, &udev->brightness,
- sizeof(udev->brightness));
- udev->new_data = false;
- retval = sizeof(udev->brightness);
+ if (copy_to_user(buffer, &udev->brightness,
+ sizeof(udev->brightness))) {
+ retval = -EFAULT;
+ } else {
+ udev->new_data = false;
+ retval = sizeof(udev->brightness);
+ }
}
mutex_unlock(&udev->mutex);
--
2.54.0