HID: i2c-hid: Limit reads to wMaxInputLength bytes for input events
authorSeth Forshee <seth.forshee@canonical.com>
Fri, 20 Feb 2015 17:45:11 +0000 (11:45 -0600)
committerJiri Kosina <jkosina@suse.cz>
Mon, 23 Feb 2015 14:10:04 +0000 (15:10 +0100)
commit6d00f37e49d95e640a3937a4a1ae07dbe92a10cb
tree5d180215f0d463f4967b4ac379ad2b86e4b0808a
parentb94993f6fb3452628bb4678ea86df33ffbfdde8d
HID: i2c-hid: Limit reads to wMaxInputLength bytes for input events

d1c7e29e8d27 (HID: i2c-hid: prevent buffer overflow in early IRQ)
changed hid_get_input() to read ihid->bufsize bytes, which can be
more than wMaxInputLength. This is the case with the Dell XPS 13
9343, and it is causing events to be missed. In some cases the
missed events are releases, which can cause the cursor to jump or
freeze, among other problems. Limit the number of bytes read to
min(wMaxInputLength, ihid->bufsize) to prevent such problems.

Fixes: d1c7e29e8d27 "HID: i2c-hid: prevent buffer overflow in early IRQ"
Signed-off-by: Seth Forshee <seth.forshee@canonical.com>
Reviewed-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
drivers/hid/i2c-hid/i2c-hid.c