diff options
| author | Dmitry Torokhov <dmitry.torokhov@gmail.com> | 2019-12-07 13:05:18 -0800 |
|---|---|---|
| committer | Jiri Kosina <jkosina@suse.cz> | 2019-12-13 13:43:15 +0100 |
| commit | 4f3882177240a1f55e45a3d241d3121341bead78 (patch) | |
| tree | 5be71989bd3da66fe7946030f96678e0e20df15f /drivers/hid/hid-input.c | |
| parent | fd0913768701612fc2b8ab9c8a5c019133e8d978 (diff) | |
HID: hid-input: clear unmapped usages
We should not be leaving half-mapped usages with potentially invalid
keycodes, as that may confuse hidinput_find_key() when the key is located
by index, which may end up feeding way too large keycode into the VT
keyboard handler and cause OOB write there:
BUG: KASAN: global-out-of-bounds in clear_bit include/asm-generic/bitops-instrumented.h:56 [inline]
BUG: KASAN: global-out-of-bounds in kbd_keycode drivers/tty/vt/keyboard.c:1411 [inline]
BUG: KASAN: global-out-of-bounds in kbd_event+0xe6b/0x3790 drivers/tty/vt/keyboard.c:1495
Write of size 8 at addr ffffffff89a1b2d8 by task syz-executor108/1722
...
kbd_keycode drivers/tty/vt/keyboard.c:1411 [inline]
kbd_event+0xe6b/0x3790 drivers/tty/vt/keyboard.c:1495
input_to_handler+0x3b6/0x4c0 drivers/input/input.c:118
input_pass_values.part.0+0x2e3/0x720 drivers/input/input.c:145
input_pass_values drivers/input/input.c:949 [inline]
input_set_keycode+0x290/0x320 drivers/input/input.c:954
evdev_handle_set_keycode_v2+0xc4/0x120 drivers/input/evdev.c:882
evdev_do_ioctl drivers/input/evdev.c:1150 [inline]
Cc: stable@vger.kernel.org
Reported-by: syzbot+19340dff067c2d3835c0@syzkaller.appspotmail.com
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Tested-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
Diffstat (limited to 'drivers/hid/hid-input.c')
| -rw-r--r-- | drivers/hid/hid-input.c | 16 |
1 files changed, 12 insertions, 4 deletions
diff --git a/drivers/hid/hid-input.c b/drivers/hid/hid-input.c index 63855f275a38..dea9cc65bf80 100644 --- a/drivers/hid/hid-input.c +++ b/drivers/hid/hid-input.c @@ -1132,9 +1132,15 @@ static void hidinput_configure_usage(struct hid_input *hidinput, struct hid_fiel } mapped: - if (device->driver->input_mapped && device->driver->input_mapped(device, - hidinput, field, usage, &bit, &max) < 0) - goto ignore; + if (device->driver->input_mapped && + device->driver->input_mapped(device, hidinput, field, usage, + &bit, &max) < 0) { + /* + * The driver indicated that no further generic handling + * of the usage is desired. + */ + return; + } set_bit(usage->type, input->evbit); @@ -1215,9 +1221,11 @@ mapped: set_bit(MSC_SCAN, input->mscbit); } -ignore: return; +ignore: + usage->type = 0; + usage->code = 0; } static void hidinput_handle_scroll(struct hid_usage *usage, |