Re: [PATCH] HID: roccat: add bounds checking in kone_sysfs_write_settings()

From: Jiri Kosina
Date: Mon Aug 17 2020 - 06:07:16 EST


On Wed, 5 Aug 2020, Dan Carpenter wrote:

> In the original code we didn't check if the new value for
> "settings->startup_profile" was within bounds that could possibly
> result in an out of bounds array acccess. What we did was we checked if
> we could write the data to the firmware and it's possibly the firmware
> checks these values but there is no way to know. It's safer and easier
> to read if we check it in the kernel as well.
>
> I also added a check to ensure that "settings->size" was correct. The
> comments say that the only valid value is 36 which is sizeof(struct
> kone_settings).
>
> Fixes: 14bf62cde794 ("HID: add driver for Roccat Kone gaming mouse")
> Signed-off-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx>

Stefan, could I please get your Reviewed-by and/or Tested-by, to make sure
this doesn't unintentionally somehow break userspace?

Thanks,

--
Jiri Kosina
SUSE Labs