[PATCH] scsi: storvsc: be more picky about scmnd->sc_data_direction

[Vitaly Kuznetsov]

KY Srinivasan <kys at microsoft.com> writes:

>> -----Original Message-----
>> From: Vitaly Kuznetsov [mailto:vkuznets at redhat.com]
>> Sent: Thursday, June 25, 2015 9:12 AM
>> To: linux-scsi at vger.kernel.org
>> Cc: Long Li; KY Srinivasan; Haiyang Zhang; James E.J. Bottomley;
>> devel at linuxdriverproject.org; linux-kernel at vger.kernel.org; Radim Krčmář
>> Subject: [PATCH] scsi: storvsc: be more picky about scmnd-
>> >sc_data_direction
>> 
>> Under the 'default' case in scmnd->sc_data_direction we have 3 options:
>> - DMA_NONE which we handle correctly.
>> - DMA_BIDIRECTIONAL which is never supposed to be set by SCSI stack.
>> - Garbage value.
>> 
>> Do WARN() and return -EINVAL in the last two cases. virtio_scsi does
>> BUG_ON() here but it looks like an overkill.
>> 
>> Reported-by: Radim Krčmář <rkrcmar at redhat.com>
>> Signed-off-by: Vitaly Kuznetsov <vkuznets at redhat.com>
> Signed-off-by: K. Y. Srinivasan <kys at microsoft.com>

Sorry for the ping but it seems the fix never made it to scsi tree...

>> ---
>>  drivers/scsi/storvsc_drv.c | 10 +++++++++-
>>  1 file changed, 9 insertions(+), 1 deletion(-)
>> 
>> diff --git a/drivers/scsi/storvsc_drv.c b/drivers/scsi/storvsc_drv.c
>> index 3c6584f..61f4855 100644
>> --- a/drivers/scsi/storvsc_drv.c
>> +++ b/drivers/scsi/storvsc_drv.c
>> @@ -1598,10 +1598,18 @@ static int storvsc_queuecommand(struct
>> Scsi_Host *host, struct scsi_cmnd *scmnd)
>>  		vm_srb->data_in = READ_TYPE;
>>  		vm_srb->win8_extension.srb_flags |=
>> SRB_FLAGS_DATA_IN;
>>  		break;
>> -	default:
>> +	case DMA_NONE:
>>  		vm_srb->data_in = UNKNOWN_TYPE;
>>  		vm_srb->win8_extension.srb_flags |=
>> SRB_FLAGS_NO_DATA_TRANSFER;
>>  		break;
>> +	default:
>> +		/*
>> +		 * This is DMA_BIDIRECTIONAL or something else we are
>> never
>> +		 * supposed to see here.
>> +		 */
>> +		WARN(1, "Unexpected data direction: %d\n",
>> +		     scmnd->sc_data_direction);
>> +		return -EINVAL;
>>  	}
>> 
>> 
>> --
>> 2.4.3

-- 
  Vitaly