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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>
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parent
042e1c7916
commit
7c4f56070f
1 changed files with 8 additions and 5 deletions
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@ -738,20 +738,23 @@ static int evdev_handle_set_keycode_v2(struct input_dev *dev, void __user *p)
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*/
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static int evdev_handle_get_val(struct evdev_client *client,
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struct input_dev *dev, unsigned int type,
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unsigned long *bits, unsigned int max,
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unsigned int size, void __user *p, int compat)
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unsigned long *bits, unsigned int maxbit,
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unsigned int maxlen, void __user *p,
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int compat)
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{
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int ret;
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unsigned long *mem;
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size_t len;
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mem = kmalloc(sizeof(unsigned long) * max, GFP_KERNEL);
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len = BITS_TO_LONGS(maxbit) * sizeof(unsigned long);
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mem = kmalloc(len, GFP_KERNEL);
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if (!mem)
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return -ENOMEM;
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spin_lock_irq(&dev->event_lock);
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spin_lock(&client->buffer_lock);
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memcpy(mem, bits, sizeof(unsigned long) * max);
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memcpy(mem, bits, len);
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spin_unlock(&dev->event_lock);
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@ -759,7 +762,7 @@ static int evdev_handle_get_val(struct evdev_client *client,
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spin_unlock_irq(&client->buffer_lock);
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ret = bits_to_user(mem, max, size, p, compat);
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ret = bits_to_user(mem, maxbit, maxlen, p, compat);
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if (ret < 0)
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evdev_queue_syn_dropped(client);
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