On Sun, 25 Apr 2021, Anirudh Rayabharam wrote:
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: <redacted>
Signed-off-by: Anirudh Rayabharam <redacted>
Benjamin, could you please run this one through your regression testing
machinery before we send it upstream?
Thanks,
--
Jiri Kosina
SUSE Labs