From: Dmitry Torokhov Date: Mon, 6 Oct 2014 17:55:49 +0000 (-0700) Subject: Input: evdev - fix EVIOCG{type} ioctl X-Git-Tag: v3.16.35~2961 X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=88ce1fe8da5b65fc548197d2574a552b97df3348;p=thirdparty%2Fkernel%2Fstable.git Input: evdev - fix EVIOCG{type} ioctl commit 7c4f56070fde2367766fa1fb04852599b5e1ad35 upstream. 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 Reviewed-by: Pavel Machek Reviewed-by: David Herrmann Signed-off-by: Dmitry Torokhov Signed-off-by: Luis Henriques --- diff --git a/drivers/input/evdev.c b/drivers/input/evdev.c index b51970d1e9ee1..f8e1f98bc2224 100644 --- a/drivers/input/evdev.c +++ b/drivers/input/evdev.c @@ -739,20 +739,23 @@ 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); @@ -760,7 +763,7 @@ 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);