Re: [PATCH 0/3] HID: hid-bigbenff: fixing three crash bugs in a gamepad driver

From: Benjamin Tissoires
Date: Tue Feb 18 2020 - 05:40:26 EST


Hi Hanno,

On Mon, Feb 17, 2020 at 4:24 PM Hanno Zulla <abos@xxxxxxxx> wrote:
>
> Hi there,
>
> the hid-bigbenff.c had three bugs causing possible kernel crashes.
>
> The first patch fixes a double free during device removal, which was
> caused by a wrong use of input_ff_create_memless(). The
> "driver-specific data to be passed into play_effect" parameter of
> input_ff_create_memless() would later be freed automatically when the ff
> device is removed. Since the driver also uses the managed resource API,
> it would automatically free the memory of this parameter twice, causing
> a general protection fault moments later.
>
> The second patch fixes the error path after hid_hw_start(), as a call
> to hid_hw_stop() is required in case of an error.
>
> The second patch also removes the hid_hw_close() call during device
> removal, as several other hid device drivers don't call this routine,
> either.
>
> The third patch adds a flag to avoid a race condition when there is
> still scheduled work left (or newly being scheduled) during or after
> device removal, which could cause a kernel crash.
>
> Thanks in advance for your review & kind regards,
>

I think the patches are correct (have you tested them with actual HW?).
However, checkpatch complains that the From and Signed-off-by email
differ. Can you send a v2 with a fix for that?

Cheers,
Benjamin