blob: 69639d2f2bae4622dd4e4d7ecf7a7e63417a9e5a [file] [log] [blame]
From cb222aed03d798fc074be55e59d9a112338ee784 Mon Sep 17 00:00:00 2001
From: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Date: Fri, 13 Dec 2019 14:56:16 -0800
Subject: Input: add safety guards to input_set_keycode()
From: Dmitry Torokhov <dmitry.torokhov@gmail.com>
commit cb222aed03d798fc074be55e59d9a112338ee784 upstream.
If we happen to have a garbage in input device's keycode table with values
too big we'll end up doing clear_bit() with offset way outside of our
bitmaps, damaging other objects within an input device or even outside of
it. Let's add sanity checks to the returned old keycodes.
Reported-by: syzbot+c769968809f9359b07aa@syzkaller.appspotmail.com
Reported-by: syzbot+76f3a30e88d256644c78@syzkaller.appspotmail.com
Link: https://lore.kernel.org/r/20191207212757.GA245964@dtor-ws
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
drivers/input/input.c | 26 ++++++++++++++++----------
1 file changed, 16 insertions(+), 10 deletions(-)
--- a/drivers/input/input.c
+++ b/drivers/input/input.c
@@ -845,16 +845,18 @@ static int input_default_setkeycode(stru
}
}
- __clear_bit(*old_keycode, dev->keybit);
- __set_bit(ke->keycode, dev->keybit);
-
- for (i = 0; i < dev->keycodemax; i++) {
- if (input_fetch_keycode(dev, i) == *old_keycode) {
- __set_bit(*old_keycode, dev->keybit);
- break; /* Setting the bit twice is useless, so break */
+ if (*old_keycode <= KEY_MAX) {
+ __clear_bit(*old_keycode, dev->keybit);
+ for (i = 0; i < dev->keycodemax; i++) {
+ if (input_fetch_keycode(dev, i) == *old_keycode) {
+ __set_bit(*old_keycode, dev->keybit);
+ /* Setting the bit twice is useless, so break */
+ break;
+ }
}
}
+ __set_bit(ke->keycode, dev->keybit);
return 0;
}
@@ -910,9 +912,13 @@ int input_set_keycode(struct input_dev *
* Simulate keyup event if keycode is not present
* in the keymap anymore
*/
- if (test_bit(EV_KEY, dev->evbit) &&
- !is_event_supported(old_keycode, dev->keybit, KEY_MAX) &&
- __test_and_clear_bit(old_keycode, dev->key)) {
+ if (old_keycode > KEY_MAX) {
+ dev_warn(dev->dev.parent ?: &dev->dev,
+ "%s: got too big old keycode %#x\n",
+ __func__, old_keycode);
+ } else if (test_bit(EV_KEY, dev->evbit) &&
+ !is_event_supported(old_keycode, dev->keybit, KEY_MAX) &&
+ __test_and_clear_bit(old_keycode, dev->key)) {
struct input_value vals[] = {
{ EV_KEY, old_keycode, 0 },
input_value_sync