Input: evdev - fix EVIOCG{type} ioctl
The 'max' size passed into the function is measured in number of bits
(KEY_MAX, LED_MAX, etc) so we need to convert it accordingly before trying
to copy the data out, otherwise we will try copying too much and end up
with up with a page fault.
Reported-by: Pavel Machek <pavel@ucw.cz>
Reviewed-by: Pavel Machek <pavel@ucw.cz>
Reviewed-by: David Herrmann <dh.herrmann@gmail.com>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
diff --git a/drivers/input/evdev.c b/drivers/input/evdev.c
index de05545..bc20348 100644
--- a/drivers/input/evdev.c
+++ b/drivers/input/evdev.c
@@ -738,20 +738,23 @@
*/
static int evdev_handle_get_val(struct evdev_client *client,
struct input_dev *dev, unsigned int type,
- unsigned long *bits, unsigned int max,
- unsigned int size, void __user *p, int compat)
+ unsigned long *bits, unsigned int maxbit,
+ unsigned int maxlen, void __user *p,
+ int compat)
{
int ret;
unsigned long *mem;
+ size_t len;
- mem = kmalloc(sizeof(unsigned long) * max, GFP_KERNEL);
+ len = BITS_TO_LONGS(maxbit) * sizeof(unsigned long);
+ mem = kmalloc(len, GFP_KERNEL);
if (!mem)
return -ENOMEM;
spin_lock_irq(&dev->event_lock);
spin_lock(&client->buffer_lock);
- memcpy(mem, bits, sizeof(unsigned long) * max);
+ memcpy(mem, bits, len);
spin_unlock(&dev->event_lock);
@@ -759,7 +762,7 @@
spin_unlock_irq(&client->buffer_lock);
- ret = bits_to_user(mem, max, size, p, compat);
+ ret = bits_to_user(mem, maxbit, maxlen, p, compat);
if (ret < 0)
evdev_queue_syn_dropped(client);