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* re: [SCSI] sd: Ensure we correctly disable devices with unknown protection type
@ 2012-09-26  8:26 Dan Carpenter
  2012-09-27  2:39 ` Martin K. Petersen
  0 siblings, 1 reply; 4+ messages in thread
From: Dan Carpenter @ 2012-09-26  8:26 UTC (permalink / raw)
  To: martin.petersen; +Cc: linux-scsi

Hi Martin,

The patch fe542396da73: "[SCSI] sd: Ensure we correctly disable
devices with unknown protection type" from Sep 21, 2012, leads to the
following warning:
include/scsi/scsi_host.h:879 scsi_host_dif_capable()
	 warn: buffer overflow 'cap' 4 <= 4

   838  enum scsi_host_prot_capabilities {
   839          SHOST_DIF_TYPE1_PROTECTION = 1 << 0, /* T10 DIF Type 1 */
   840          SHOST_DIF_TYPE2_PROTECTION = 1 << 1, /* T10 DIF Type 2 */
   841          SHOST_DIF_TYPE3_PROTECTION = 1 << 2, /* T10 DIF Type 3 */
   842  
   843          SHOST_DIX_TYPE0_PROTECTION = 1 << 3, /* DIX between OS and HBA only */
   844          SHOST_DIX_TYPE1_PROTECTION = 1 << 4, /* DIX with DIF Type 1 */
   845          SHOST_DIX_TYPE2_PROTECTION = 1 << 5, /* DIX with DIF Type 2 */
   846          SHOST_DIX_TYPE3_PROTECTION = 1 << 6, /* DIX with DIF Type 3 */
   847  };

   869  static inline unsigned int scsi_host_dif_capable(struct Scsi_Host *shost, unsigned int target_type)
   870  {
   871          static unsigned char cap[] = { 0,
   872                                         SHOST_DIF_TYPE1_PROTECTION,
   873                                         SHOST_DIF_TYPE2_PROTECTION,
   874                                         SHOST_DIF_TYPE3_PROTECTION };
   875  
   876          if (target_type > SHOST_DIF_TYPE3_PROTECTION)
   877                  return 0;
   878  
   879          return shost->prot_capabilities & cap[target_type] ? target_type : 0;
                                                  ^^^^^^^^^^^^^^^^
It looks like we're doing cap[1 << 2] here not cap[2].

   880  }

   882  static inline unsigned int scsi_host_dix_capable(struct Scsi_Host *shost, unsigned int target_type)
   883  {
   884  #if defined(CONFIG_BLK_DEV_INTEGRITY)
   885          static unsigned char cap[] = { SHOST_DIX_TYPE0_PROTECTION,
   886                                         SHOST_DIX_TYPE1_PROTECTION,
   887                                         SHOST_DIX_TYPE2_PROTECTION,
   888                                         SHOST_DIX_TYPE3_PROTECTION };
   889  
   890          if (target_type > SHOST_DIX_TYPE3_PROTECTION)
   891                  return 0;
   892  
   893          return shost->prot_capabilities & cap[target_type];
                                                  ^^^^^^^^^^^^^^^^^
We're doing cap[1 << 6] here, not cap[6];

   894  #endif
   895          return 0;
   896  }

regards,
dan carpenter


^ permalink raw reply	[flat|nested] 4+ messages in thread

* Re: [SCSI] sd: Ensure we correctly disable devices with unknown protection type
  2012-09-26  8:26 [SCSI] sd: Ensure we correctly disable devices with unknown protection type Dan Carpenter
@ 2012-09-27  2:39 ` Martin K. Petersen
  2013-02-06 19:29   ` Dan Carpenter
  0 siblings, 1 reply; 4+ messages in thread
From: Martin K. Petersen @ 2012-09-27  2:39 UTC (permalink / raw)
  To: Dan Carpenter; +Cc: martin.petersen, linux-scsi

>>>>> "Dan" == Dan Carpenter <dan.carpenter@oracle.com> writes:

Dan,

Dan> 	 warn: buffer overflow 'cap' 4 <= 4

Argh, yes. Type 3 is 4 because it's a bitmask.

-- 
Martin K. Petersen	Oracle Linux Engineering


SCSI: Fix range check in scsi_host.h

The range checking from fe542396 was bad. We would still end up walking
beyond the array as Type 3 is defined to be 4 in the protection
bitmask. Instead use ARRAY_SIZE() for the range check.

Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

diff --git a/include/scsi/scsi_host.h b/include/scsi/scsi_host.h
index 4908480..2b6956e 100644
--- a/include/scsi/scsi_host.h
+++ b/include/scsi/scsi_host.h
@@ -873,7 +873,7 @@ static inline unsigned int scsi_host_dif_capable(struct Scsi_Host *shost, unsign
 				       SHOST_DIF_TYPE2_PROTECTION,
 				       SHOST_DIF_TYPE3_PROTECTION };
 
-	if (target_type > SHOST_DIF_TYPE3_PROTECTION)
+	if (target_type >= ARRAY_SIZE(cap))
 		return 0;
 
 	return shost->prot_capabilities & cap[target_type] ? target_type : 0;
@@ -887,7 +887,7 @@ static inline unsigned int scsi_host_dix_capable(struct Scsi_Host *shost, unsign
 				       SHOST_DIX_TYPE2_PROTECTION,
 				       SHOST_DIX_TYPE3_PROTECTION };
 
-	if (target_type > SHOST_DIX_TYPE3_PROTECTION)
+	if (target_type >= ARRAY_SIZE(cap))
 		return 0;
 
 	return shost->prot_capabilities & cap[target_type];

^ permalink raw reply related	[flat|nested] 4+ messages in thread

* Re: [SCSI] sd: Ensure we correctly disable devices with unknown protection type
  2012-09-27  2:39 ` Martin K. Petersen
@ 2013-02-06 19:29   ` Dan Carpenter
  2013-02-07 19:24     ` Martin K. Petersen
  0 siblings, 1 reply; 4+ messages in thread
From: Dan Carpenter @ 2013-02-06 19:29 UTC (permalink / raw)
  To: Martin K. Petersen; +Cc: linux-scsi

This patch wasn't applied.  Probably because it didn't have
[PATCH] in the email subject.

regards,
dan carpenter

On Wed, Sep 26, 2012 at 10:39:44PM -0400, Martin K. Petersen wrote:
> >>>>> "Dan" == Dan Carpenter <dan.carpenter@oracle.com> writes:
> 
> Dan,
> 
> Dan> 	 warn: buffer overflow 'cap' 4 <= 4
> 
> Argh, yes. Type 3 is 4 because it's a bitmask.
> 
> -- 
> Martin K. Petersen	Oracle Linux Engineering
> 
> 
> SCSI: Fix range check in scsi_host.h
> 
> The range checking from fe542396 was bad. We would still end up walking
> beyond the array as Type 3 is defined to be 4 in the protection
> bitmask. Instead use ARRAY_SIZE() for the range check.
> 
> Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
> 
> diff --git a/include/scsi/scsi_host.h b/include/scsi/scsi_host.h
> index 4908480..2b6956e 100644
> --- a/include/scsi/scsi_host.h
> +++ b/include/scsi/scsi_host.h
> @@ -873,7 +873,7 @@ static inline unsigned int scsi_host_dif_capable(struct Scsi_Host *shost, unsign
>  				       SHOST_DIF_TYPE2_PROTECTION,
>  				       SHOST_DIF_TYPE3_PROTECTION };
>  
> -	if (target_type > SHOST_DIF_TYPE3_PROTECTION)
> +	if (target_type >= ARRAY_SIZE(cap))
>  		return 0;
>  
>  	return shost->prot_capabilities & cap[target_type] ? target_type : 0;
> @@ -887,7 +887,7 @@ static inline unsigned int scsi_host_dix_capable(struct Scsi_Host *shost, unsign
>  				       SHOST_DIX_TYPE2_PROTECTION,
>  				       SHOST_DIX_TYPE3_PROTECTION };
>  
> -	if (target_type > SHOST_DIX_TYPE3_PROTECTION)
> +	if (target_type >= ARRAY_SIZE(cap))
>  		return 0;
>  
>  	return shost->prot_capabilities & cap[target_type];

^ permalink raw reply	[flat|nested] 4+ messages in thread

* Re: [SCSI] sd: Ensure we correctly disable devices with unknown protection type
  2013-02-06 19:29   ` Dan Carpenter
@ 2013-02-07 19:24     ` Martin K. Petersen
  0 siblings, 0 replies; 4+ messages in thread
From: Martin K. Petersen @ 2013-02-07 19:24 UTC (permalink / raw)
  To: Dan Carpenter; +Cc: Martin K. Petersen, linux-scsi

>>>>> "Dan" == Dan Carpenter <dan.carpenter@oracle.com> writes:

Dan> This patch wasn't applied.

Nope, but it hasn't been forgotten. I have it in my resubmit queue with
a couple of other stable fixes.

-- 
Martin K. Petersen	Oracle Linux Engineering

^ permalink raw reply	[flat|nested] 4+ messages in thread

end of thread, other threads:[~2013-02-07 19:24 UTC | newest]

Thread overview: 4+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2012-09-26  8:26 [SCSI] sd: Ensure we correctly disable devices with unknown protection type Dan Carpenter
2012-09-27  2:39 ` Martin K. Petersen
2013-02-06 19:29   ` Dan Carpenter
2013-02-07 19:24     ` Martin K. Petersen

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