Re: [PATCH] staging:iio:events: Make sure userspace buffer is large enough

[Jonathan Cameron <jic23@cam.ac.uk>]

On 10/24/11 12:52, Lars-Peter Clausen wrote:
> Make sure that the userspace buffer is large enough to hold a iio_event_data
> struct before writing to it.
> 
Good catch.  Shall I tack this on the end of the two fixes sets I sent earlier?
> Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Acked-by: Jonathan Cameron <jic23@cam.ac.uk>
> ---
>  drivers/staging/iio/industrialio-core.c |    6 ++++--
>  1 files changed, 4 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/staging/iio/industrialio-core.c b/drivers/staging/iio/industrialio-core.c
> index 74904f1..733e83a 100644
> --- a/drivers/staging/iio/industrialio-core.c
> +++ b/drivers/staging/iio/industrialio-core.c
> @@ -169,8 +169,11 @@ static ssize_t iio_event_chrdev_read(struct file *filep,
>  {
>  	struct iio_event_interface *ev_int = filep->private_data;
>  	struct iio_detected_event_list *el;
> +	size_t len = sizeof(el->ev);
>  	int ret;
> -	size_t len;
> +
> +	if (count < len)
> +		return -EINVAL;
>  
>  	mutex_lock(&ev_int->event_list_lock);
>  	if (list_empty(&ev_int->det_events)) {
> @@ -192,7 +195,6 @@ static ssize_t iio_event_chrdev_read(struct file *filep,
>  	el = list_first_entry(&ev_int->det_events,
>  			      struct iio_detected_event_list,
>  			      list);
> -	len = sizeof el->ev;
>  	if (copy_to_user(buf, &(el->ev), len)) {
>  		ret = -EFAULT;
>  		goto error_mutex_unlock;