Re: [PATCH] HID: rmi: Check that the RMI_STARTED bit is set before unregistering the RMI transport device

[Andrew Duggan]

Hi Jiri,

On 11/15/19 7:26 AM, Jiri Kosina wrote:
> On Wed, 23 Oct 2019, Andrew Duggan wrote:
>
>> In the event that the RMI device is unreachable, the calls to
>> rmi_set_mode() or rmi_set_page() will fail before registering the RMI
>> transport device. When the device is removed, rmi_remove() will call
>> rmi_unregister_transport_device() which will attempt to access the
>> rmi_dev pointer which was not set. This patch adds a check of the
>> RMI_STARTED bit before calling rmi_unregister_transport_device().
>> The RMI_STARTED bit is only set after rmi_register_transport_device()
>> completes successfully. A subsequent patch in the RMI core will add
>> checks to validate the pointers before accessing them.
> Andrew,
>
> my mailbox doesn't seem to have that 'subsequent patch' ... was it ever
> sent and I missed it? If so, could you please resend it?

The subsequent patch which I was referring to is:

https://lore.kernel.org/linux-input/20191023012344.20998-2-aduggan@xxxxxxxxxxxxx/

Since this second patch was for the input subsystem I decided to just 
make them separate patches instead of creating a series. However, based 
on Dmitry's feedback it was determined that the second patch wasn't a 
good idea and it won't be applied. This first patch is enough to fix the 
issue by preventing the call to rmi_unregister_transport_device() if the 
subsequent call to register failed. The only change I would make to this 
patch would be to remove the last sentence of the comment. If you choose 
to apply that patch then would this be a change you would make? Or would 
you prefer I submit a v2 with this update?

Thanks,

Andrew


> Thanks,
>
> --
> Jiri Kosina
> SUSE Labs
>