On Mon, Oct 23, 2017 at 01:24:23PM +0200, Andrey Konovalov wrote:

Hi!

I've got the following report while fuzzing the kernel with syzkaller.

On commit 3e0cc09a3a2c40ec1ffb6b4e12da86e98feccb11 (4.14-rc5+).

parse_hid_report_descriptor() has a while (i < length) loop, which
only guarantees that there's at least 1 byte in the buffer, but the
loop body can read multiple bytes which causes out-of-bounds access.

Ugh, this whole driver should be moved over to HID, but I am not sure
who has hardware to test... I just sent a patch plugging this hole.

Thanks for the report.

-- 
Dmitry