HID: usbhid: fix info leak in hid_submit_ctrl
authorAnirudh Rayabharam <mail@anirudhrb.com>
Sun, 25 Apr 2021 17:33:53 +0000 (23:03 +0530)
committerJiri Kosina <jkosina@suse.cz>
Wed, 5 May 2021 13:52:34 +0000 (15:52 +0200)
commit6be388f4a35d2ce5ef7dbf635a8964a5da7f799f
tree6e4a7f2bd3471fa91be4a74f4eeafe49d77598eb
parent48e33befe61a7d407753c53d1a06fc8d6b5dab80
HID: usbhid: fix info leak in hid_submit_ctrl

In hid_submit_ctrl(), the way of calculating the report length doesn't
take into account that report->size can be zero. When running the
syzkaller reproducer, a report of size 0 causes hid_submit_ctrl) to
calculate transfer_buffer_length as 16384. When this urb is passed to
the usb core layer, KMSAN reports an info leak of 16384 bytes.

To fix this, first modify hid_report_len() to account for the zero
report size case by using DIV_ROUND_UP for the division. Then, call it
from hid_submit_ctrl().

Reported-by: syzbot+7c2bb71996f95a82524c@syzkaller.appspotmail.com
Signed-off-by: Anirudh Rayabharam <mail@anirudhrb.com>
Acked-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
drivers/hid/usbhid/hid-core.c
include/linux/hid.h