Re: [PATCH 1/2] s390/vfio-ap: unpin pages on gisc registration failure

[Tony Krowiak <akrowiak@linux.ibm.com>]

On 9/13/23 14:10, Matthew Rosato wrote:
> On 9/13/23 9:06 AM, Tony Krowiak wrote:
>> From: Anthony Krowiak <akrowiak@linux.ibm.com>
>>
>> In the vfio_ap_irq_enable function, after the page containing the
>> notification indicator byte (NIB) is pinned, the function attempts
>> to register the guest ISC. If registration fails, the function sets the
>> status response code and returns without unpinning the page containing
>> the NIB. In order to avoid a memory leak, the NIB should be unpinned before
>> returning from the vfio_ap_irq_enable function.
>>
>> Fixes: 783f0a3ccd79 ("s390/vfio-ap: add s390dbf logging to the vfio_ap_irq_enable function")
>>
>> Signed-off-by: Janosch Frank <frankja@linux.ibm.com>
>> Signed-off-by: Anthony Krowiak <akrowiak@linux.ibm.com>
>> Cc: <stable@vger.kernel.org>
> 
> Oops, good find.

Yes, thanks to Janosch/

> 
> Reviewed-by: Matthew Rosato <mjrosato@linux.ibm.com>
> 
>> ---
>>   drivers/s390/crypto/vfio_ap_ops.c | 1 +
>>   1 file changed, 1 insertion(+)
>>
>> diff --git a/drivers/s390/crypto/vfio_ap_ops.c b/drivers/s390/crypto/vfio_ap_ops.c
>> index 4db538a55192..9cb28978c186 100644
>> --- a/drivers/s390/crypto/vfio_ap_ops.c
>> +++ b/drivers/s390/crypto/vfio_ap_ops.c
>> @@ -457,6 +457,7 @@ static struct ap_queue_status vfio_ap_irq_enable(struct vfio_ap_queue *q,
>>   		VFIO_AP_DBF_WARN("%s: gisc registration failed: nisc=%d, isc=%d, apqn=%#04x\n",
>>   				 __func__, nisc, isc, q->apqn);
>>   
>> +		vfio_unpin_pages(&q->matrix_mdev->vdev, nib, 1);
>>   		status.response_code = AP_RESPONSE_INVALID_GISA;
>>   		return status;
>>   	}
>