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Commit 7c4f5607 authored by Dmitry Torokhov's avatar Dmitry Torokhov
Browse files

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: default avatarPavel Machek <pavel@ucw.cz>
Reviewed-by: default avatarPavel Machek <pavel@ucw.cz>
Reviewed-by: default avatarDavid Herrmann <dh.herrmann@gmail.com>
Signed-off-by: default avatarDmitry Torokhov <dmitry.torokhov@gmail.com>
parent 042e1c79

drivers/input/evdev.c

+8 −5
Original line number Diff line number Diff line
@@ -738,20 +738,23 @@ static int evdev_handle_set_keycode_v2(struct input_dev *dev, void __user *p) 
 */

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 @@ static int evdev_handle_get_val(struct evdev_client *client, 


	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);