HID: lenovo: Check hid_get_drvdata() returns non NULL in lenovo_event()
authorHans de Goede <hdegoede@redhat.com>
Sun, 4 Apr 2021 08:04:26 +0000 (10:04 +0200)
committerJiri Kosina <jkosina@suse.cz>
Wed, 7 Apr 2021 10:48:19 +0000 (12:48 +0200)
commit34348a8661e3cd67dcf6938f08c8bb77522301f7
treef4ba81c52cda35fc90d48b4930d42be7eb28d6c2
parent658d04e6eb6be1601ae95d7bee92bbf4096cdc1e
HID: lenovo: Check hid_get_drvdata() returns non NULL in lenovo_event()

The HID lenovo probe function only attaches drvdata to one of the
USB interfaces, but lenovo_event() will get called for all USB interfaces
to which hid-lenovo is bound.

This allows a malicious device to fake being a device handled by
hid-lenovo, which generates events for which lenovo_event() has
special handling (and thus dereferences hid_get_drvdata()) on another
interface triggering a NULL pointer exception.

Add a check for hid_get_drvdata() returning NULL, avoiding this
possible NULL pointer exception.

Fixes: bc04b37ea0ec ("HID: lenovo: Add ThinkPad 10 Ultrabook Keyboard support")
Reviewed-by: Marek BehĂșn <kabel@kernel.org>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
drivers/hid/hid-lenovo.c