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

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

[Vitaly Kuznetsov]

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@redhat.com>
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
---
 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

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

[KY Srinivasan]

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> -----Original Message-----
> From: Vitaly Kuznetsov [mailto:vkuznets@redhat.com]
> Sent: Thursday, June 25, 2015 9:12 AM
> To: linux-scsi@vger.kernel.org
> Cc: Long Li; KY Srinivasan; Haiyang Zhang; James E.J. Bottomley;
> devel@linuxdriverproject.org; linux-kernel@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@redhat.com>
> Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
> ---
>  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

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

[Vitaly Kuznetsov]

KY Srinivasan <kys@microsoft.com> writes:

>> -----Original Message-----
>> From: Vitaly Kuznetsov [mailto:vkuznets@redhat.com]
>> Sent: Thursday, June 25, 2015 9:12 AM
>> To: linux-scsi@vger.kernel.org
>> Cc: Long Li; KY Srinivasan; Haiyang Zhang; James E.J. Bottomley;
>> devel@linuxdriverproject.org; linux-kernel@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@redhat.com>
>> Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
> Signed-off-by: K. Y. Srinivasan <kys@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