[PATCH] ses: fix additional element traversal bug

[PATCH] ses: fix additional element traversal bug

[James Bottomley]

KASAN found that our additional element processing scripts drop off
the end of the VPD page into unallocated space.  The reason is that
not every element has additional information but our traversal
routines think they do, leading to them expecting far more additional
information than is present.  Fix this by adding a gate to the
traversal routine so that it only processes elements that are expected
to have additional information (list is in SES-2 section 6.1.13.1:
Additional Element Status diagnostic page overview)

Reported-by: Pavel Tikhomirov <ptikhomirov@virtuozzo.com>
Tested-by: Pavel Tikhomirov <ptikhomirov@virtuozzo.com>
Cc: stable@vger.kernel.org
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>

---

diff --git a/drivers/scsi/ses.c b/drivers/scsi/ses.c
index 1736935..53ef1cb 100644
--- a/drivers/scsi/ses.c
+++ b/drivers/scsi/ses.c
@@ -561,7 +561,15 @@ static void ses_enclosure_data_process(struct enclosure_device *edev,
 			if (desc_ptr)
 				desc_ptr += len;
 
-			if (addl_desc_ptr)
+			if (addl_desc_ptr &&
+			    /* only find additional descriptions for specific devices */
+			    (type_ptr[0] == ENCLOSURE_COMPONENT_DEVICE ||
+			     type_ptr[0] == ENCLOSURE_COMPONENT_ARRAY_DEVICE ||
+			     type_ptr[0] == ENCLOSURE_COMPONENT_SAS_EXPANDER ||
+			     /* these elements are optional */
+			     type_ptr[0] == ENCLOSURE_COMPONENT_SCSI_TARGET_PORT ||
+			     type_ptr[0] == ENCLOSURE_COMPONENT_SCSI_INITIATOR_PORT ||
+			     type_ptr[0] == ENCLOSURE_COMPONENT_CONTROLLER_ELECTRONICS))
 				addl_desc_ptr += addl_desc_ptr[1] + 2;
 
 		}
diff --git a/include/linux/enclosure.h b/include/linux/enclosure.h
index 7be22da..a4cf57c 100644
--- a/include/linux/enclosure.h
+++ b/include/linux/enclosure.h
@@ -29,7 +29,11 @@
 /* A few generic types ... taken from ses-2 */
 enum enclosure_component_type {
 	ENCLOSURE_COMPONENT_DEVICE = 0x01,
+	ENCLOSURE_COMPONENT_CONTROLLER_ELECTRONICS = 0x07,
+	ENCLOSURE_COMPONENT_SCSI_TARGET_PORT = 0x14,
+	ENCLOSURE_COMPONENT_SCSI_INITIATOR_PORT = 0x15,
 	ENCLOSURE_COMPONENT_ARRAY_DEVICE = 0x17,
+	ENCLOSURE_COMPONENT_SAS_EXPANDER = 0x18,
 };
 
 /* ses-2 common element status */

Re: [PATCH] ses: fix additional element traversal bug

[Hannes Reinecke]

On 12/11/2015 06:16 PM, James Bottomley wrote:
> KASAN found that our additional element processing scripts drop off
> the end of the VPD page into unallocated space.  The reason is that
> not every element has additional information but our traversal
> routines think they do, leading to them expecting far more additional
> information than is present.  Fix this by adding a gate to the
> traversal routine so that it only processes elements that are expected
> to have additional information (list is in SES-2 section 6.1.13.1:
> Additional Element Status diagnostic page overview)
>
> Reported-by: Pavel Tikhomirov <ptikhomirov@virtuozzo.com>
> Tested-by: Pavel Tikhomirov <ptikhomirov@virtuozzo.com>
> Cc: stable@vger.kernel.org
> Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
>
> ---
>
> diff --git a/drivers/scsi/ses.c b/drivers/scsi/ses.c
> index 1736935..53ef1cb 100644
> --- a/drivers/scsi/ses.c
> +++ b/drivers/scsi/ses.c
> @@ -561,7 +561,15 @@ static void ses_enclosure_data_process(struct enclosure_device *edev,
>   			if (desc_ptr)
>   				desc_ptr += len;
>
> -			if (addl_desc_ptr)
> +			if (addl_desc_ptr &&
> +			    /* only find additional descriptions for specific devices */
> +			    (type_ptr[0] == ENCLOSURE_COMPONENT_DEVICE ||
> +			     type_ptr[0] == ENCLOSURE_COMPONENT_ARRAY_DEVICE ||
> +			     type_ptr[0] == ENCLOSURE_COMPONENT_SAS_EXPANDER ||
> +			     /* these elements are optional */
> +			     type_ptr[0] == ENCLOSURE_COMPONENT_SCSI_TARGET_PORT ||
> +			     type_ptr[0] == ENCLOSURE_COMPONENT_SCSI_INITIATOR_PORT ||
> +			     type_ptr[0] == ENCLOSURE_COMPONENT_CONTROLLER_ELECTRONICS))
>   				addl_desc_ptr += addl_desc_ptr[1] + 2;
>
>   		}
> diff --git a/include/linux/enclosure.h b/include/linux/enclosure.h
> index 7be22da..a4cf57c 100644
> --- a/include/linux/enclosure.h
> +++ b/include/linux/enclosure.h
> @@ -29,7 +29,11 @@
>   /* A few generic types ... taken from ses-2 */
>   enum enclosure_component_type {
>   	ENCLOSURE_COMPONENT_DEVICE = 0x01,
> +	ENCLOSURE_COMPONENT_CONTROLLER_ELECTRONICS = 0x07,
> +	ENCLOSURE_COMPONENT_SCSI_TARGET_PORT = 0x14,
> +	ENCLOSURE_COMPONENT_SCSI_INITIATOR_PORT = 0x15,
>   	ENCLOSURE_COMPONENT_ARRAY_DEVICE = 0x17,
> +	ENCLOSURE_COMPONENT_SAS_EXPANDER = 0x18,
>   };
>
>   /* ses-2 common element status */
>
Reviewed-by: Hannes Reinecke <hare@suse.com>

Cheers,

Hannes
-- 
Dr. Hannes Reinecke		               zSeries & Storage
hare@suse.de			               +49 911 74053 688
SUSE LINUX GmbH, Maxfeldstr. 5, 90409 Nürnberg
GF: F. Imendörffer, J. Smithard, J. Guild, D. Upmanyu, G. Norton
HRB 21284 (AG Nürnberg)
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