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* [PATCHv2] Fix EDD3.0 data verification.
@ 2011-02-03 12:29 Gleb Natapov
  2011-02-08 14:53 ` Gleb Natapov
  0 siblings, 1 reply; 6+ messages in thread
From: Gleb Natapov @ 2011-02-03 12:29 UTC (permalink / raw)
  To: linux-kernel; +Cc: H. Peter Anvin, Thomas Gleixner, Ingo Molnar, x86

Check for nonzero path in edd_has_edd30() has no sense. First, it looks
at the wrong memory. Device path starts at offset 30 of the info->params
structure which is at offset 8 from the beginning of info structure, but
code looks at info + 4 instead. This was correct when code was introduced,
but around v2.6.4 three more fields were added to edd_info structure
(commit 66b61a5c in history.git). Second, even if it will check correct
memory it will always succeed since at offset 30 (params->key) there will
be non-zero values otherwise previous check would fail.

The patch replaces this bogus check with one that verifies checksum.

Signed-off-by: Gleb Natapov <gleb@redhat.com>
---
v1->v2
  use device path info length to calculate csum.

diff --git a/drivers/firmware/edd.c b/drivers/firmware/edd.c
index 96c25d9..f1b7f65 100644
--- a/drivers/firmware/edd.c
+++ b/drivers/firmware/edd.c
@@ -531,8 +531,8 @@ static int
 edd_has_edd30(struct edd_device *edev)
 {
 	struct edd_info *info;
-	int i, nonzero_path = 0;
-	char c;
+	int i;
+	u8 csum = 0;
 
 	if (!edev)
 		return 0;
@@ -544,16 +544,16 @@ edd_has_edd30(struct edd_device *edev)
 		return 0;
 	}
 
-	for (i = 30; i <= 73; i++) {
-		c = *(((uint8_t *) info) + i + 4);
-		if (c) {
-			nonzero_path++;
-			break;
-		}
-	}
-	if (!nonzero_path) {
+
+	/* We support only T13 spec */
+	if (info->params.device_path_info_length != 44)
+		return 0;
+
+	for (i = 30; i < info->params.device_path_info_length + 30; i++)
+		csum += *(((u8 *)&info->params) + i);
+
+	if (csum)
 		return 0;
-	}
 
 	return 1;
 }
--
			Gleb.

^ permalink raw reply	[flat|nested] 6+ messages in thread

* Re: [PATCHv2] Fix EDD3.0 data verification.
  2011-02-03 12:29 [PATCHv2] Fix EDD3.0 data verification Gleb Natapov
@ 2011-02-08 14:53 ` Gleb Natapov
  2011-02-16 15:09   ` Gleb Natapov
  0 siblings, 1 reply; 6+ messages in thread
From: Gleb Natapov @ 2011-02-08 14:53 UTC (permalink / raw)
  To: linux-kernel; +Cc: H. Peter Anvin, Thomas Gleixner, Ingo Molnar, x86

Peter, ping.

Is this version acceptable?

On Thu, Feb 03, 2011 at 02:29:48PM +0200, Gleb Natapov wrote:
> Check for nonzero path in edd_has_edd30() has no sense. First, it looks
> at the wrong memory. Device path starts at offset 30 of the info->params
> structure which is at offset 8 from the beginning of info structure, but
> code looks at info + 4 instead. This was correct when code was introduced,
> but around v2.6.4 three more fields were added to edd_info structure
> (commit 66b61a5c in history.git). Second, even if it will check correct
> memory it will always succeed since at offset 30 (params->key) there will
> be non-zero values otherwise previous check would fail.
> 
> The patch replaces this bogus check with one that verifies checksum.
> 
> Signed-off-by: Gleb Natapov <gleb@redhat.com>
> ---
> v1->v2
>   use device path info length to calculate csum.
> 
> diff --git a/drivers/firmware/edd.c b/drivers/firmware/edd.c
> index 96c25d9..f1b7f65 100644
> --- a/drivers/firmware/edd.c
> +++ b/drivers/firmware/edd.c
> @@ -531,8 +531,8 @@ static int
>  edd_has_edd30(struct edd_device *edev)
>  {
>  	struct edd_info *info;
> -	int i, nonzero_path = 0;
> -	char c;
> +	int i;
> +	u8 csum = 0;
>  
>  	if (!edev)
>  		return 0;
> @@ -544,16 +544,16 @@ edd_has_edd30(struct edd_device *edev)
>  		return 0;
>  	}
>  
> -	for (i = 30; i <= 73; i++) {
> -		c = *(((uint8_t *) info) + i + 4);
> -		if (c) {
> -			nonzero_path++;
> -			break;
> -		}
> -	}
> -	if (!nonzero_path) {
> +
> +	/* We support only T13 spec */
> +	if (info->params.device_path_info_length != 44)
> +		return 0;
> +
> +	for (i = 30; i < info->params.device_path_info_length + 30; i++)
> +		csum += *(((u8 *)&info->params) + i);
> +
> +	if (csum)
>  		return 0;
> -	}
>  
>  	return 1;
>  }
> --
> 			Gleb.
> --
> To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at  http://vger.kernel.org/majordomo-info.html
> Please read the FAQ at  http://www.tux.org/lkml/

--
			Gleb.

^ permalink raw reply	[flat|nested] 6+ messages in thread

* Re: [PATCHv2] Fix EDD3.0 data verification.
  2011-02-08 14:53 ` Gleb Natapov
@ 2011-02-16 15:09   ` Gleb Natapov
  2011-02-16 18:57     ` H. Peter Anvin
  0 siblings, 1 reply; 6+ messages in thread
From: Gleb Natapov @ 2011-02-16 15:09 UTC (permalink / raw)
  To: linux-kernel; +Cc: H. Peter Anvin, Thomas Gleixner, Ingo Molnar, x86

On Tue, Feb 08, 2011 at 04:53:01PM +0200, Gleb Natapov wrote:
> Peter, ping.
> 
> Is this version acceptable?
> 
Ping?

> On Thu, Feb 03, 2011 at 02:29:48PM +0200, Gleb Natapov wrote:
> > Check for nonzero path in edd_has_edd30() has no sense. First, it looks
> > at the wrong memory. Device path starts at offset 30 of the info->params
> > structure which is at offset 8 from the beginning of info structure, but
> > code looks at info + 4 instead. This was correct when code was introduced,
> > but around v2.6.4 three more fields were added to edd_info structure
> > (commit 66b61a5c in history.git). Second, even if it will check correct
> > memory it will always succeed since at offset 30 (params->key) there will
> > be non-zero values otherwise previous check would fail.
> > 
> > The patch replaces this bogus check with one that verifies checksum.
> > 
> > Signed-off-by: Gleb Natapov <gleb@redhat.com>
> > ---
> > v1->v2
> >   use device path info length to calculate csum.
> > 
> > diff --git a/drivers/firmware/edd.c b/drivers/firmware/edd.c
> > index 96c25d9..f1b7f65 100644
> > --- a/drivers/firmware/edd.c
> > +++ b/drivers/firmware/edd.c
> > @@ -531,8 +531,8 @@ static int
> >  edd_has_edd30(struct edd_device *edev)
> >  {
> >  	struct edd_info *info;
> > -	int i, nonzero_path = 0;
> > -	char c;
> > +	int i;
> > +	u8 csum = 0;
> >  
> >  	if (!edev)
> >  		return 0;
> > @@ -544,16 +544,16 @@ edd_has_edd30(struct edd_device *edev)
> >  		return 0;
> >  	}
> >  
> > -	for (i = 30; i <= 73; i++) {
> > -		c = *(((uint8_t *) info) + i + 4);
> > -		if (c) {
> > -			nonzero_path++;
> > -			break;
> > -		}
> > -	}
> > -	if (!nonzero_path) {
> > +
> > +	/* We support only T13 spec */
> > +	if (info->params.device_path_info_length != 44)
> > +		return 0;
> > +
> > +	for (i = 30; i < info->params.device_path_info_length + 30; i++)
> > +		csum += *(((u8 *)&info->params) + i);
> > +
> > +	if (csum)
> >  		return 0;
> > -	}
> >  
> >  	return 1;
> >  }
> > --
> > 			Gleb.
> > --
> > To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
> > the body of a message to majordomo@vger.kernel.org
> > More majordomo info at  http://vger.kernel.org/majordomo-info.html
> > Please read the FAQ at  http://www.tux.org/lkml/
> 
> --
> 			Gleb.
> --
> To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at  http://vger.kernel.org/majordomo-info.html
> Please read the FAQ at  http://www.tux.org/lkml/

--
			Gleb.

^ permalink raw reply	[flat|nested] 6+ messages in thread

* Re: [PATCHv2] Fix EDD3.0 data verification.
  2011-02-16 15:09   ` Gleb Natapov
@ 2011-02-16 18:57     ` H. Peter Anvin
  2011-03-16  8:57       ` Gleb Natapov
  0 siblings, 1 reply; 6+ messages in thread
From: H. Peter Anvin @ 2011-02-16 18:57 UTC (permalink / raw)
  To: Gleb Natapov; +Cc: linux-kernel, Thomas Gleixner, Ingo Molnar, x86

On 02/16/2011 07:09 AM, Gleb Natapov wrote:
> On Tue, Feb 08, 2011 at 04:53:01PM +0200, Gleb Natapov wrote:
>> Peter, ping.
>>
>> Is this version acceptable?
>>
> Ping?
> 

Yes, looks good... I'll try to pull it into the tree today.

	-hpa

-- 
H. Peter Anvin, Intel Open Source Technology Center
I work for Intel.  I don't speak on their behalf.


^ permalink raw reply	[flat|nested] 6+ messages in thread

* Re: [PATCHv2] Fix EDD3.0 data verification.
  2011-02-16 18:57     ` H. Peter Anvin
@ 2011-03-16  8:57       ` Gleb Natapov
  2011-04-05 15:41         ` Gleb Natapov
  0 siblings, 1 reply; 6+ messages in thread
From: Gleb Natapov @ 2011-03-16  8:57 UTC (permalink / raw)
  To: H. Peter Anvin; +Cc: linux-kernel, Thomas Gleixner, Ingo Molnar, x86

On Wed, Feb 16, 2011 at 10:57:01AM -0800, H. Peter Anvin wrote:
> On 02/16/2011 07:09 AM, Gleb Natapov wrote:
> > On Tue, Feb 08, 2011 at 04:53:01PM +0200, Gleb Natapov wrote:
> >> Peter, ping.
> >>
> >> Is this version acceptable?
> >>
> > Ping?
> > 
> 
> Yes, looks good... I'll try to pull it into the tree today.
> 
Hi Peter,

Was this applied? Will it go to 2.6.39?

--
			Gleb.

^ permalink raw reply	[flat|nested] 6+ messages in thread

* Re: [PATCHv2] Fix EDD3.0 data verification.
  2011-03-16  8:57       ` Gleb Natapov
@ 2011-04-05 15:41         ` Gleb Natapov
  0 siblings, 0 replies; 6+ messages in thread
From: Gleb Natapov @ 2011-04-05 15:41 UTC (permalink / raw)
  To: H. Peter Anvin; +Cc: linux-kernel, Thomas Gleixner, Ingo Molnar, x86

On Wed, Mar 16, 2011 at 10:57:04AM +0200, Gleb Natapov wrote:
> On Wed, Feb 16, 2011 at 10:57:01AM -0800, H. Peter Anvin wrote:
> > On 02/16/2011 07:09 AM, Gleb Natapov wrote:
> > > On Tue, Feb 08, 2011 at 04:53:01PM +0200, Gleb Natapov wrote:
> > >> Peter, ping.
> > >>
> > >> Is this version acceptable?
> > >>
> > > Ping?
> > > 
> > 
> > Yes, looks good... I'll try to pull it into the tree today.
> > 
> Hi Peter,
> 
> Was this applied? Will it go to 2.6.39?
> 
Ping. The patch is still not applied it seams.

--
			Gleb.

^ permalink raw reply	[flat|nested] 6+ messages in thread

end of thread, other threads:[~2011-04-05 15:42 UTC | newest]

Thread overview: 6+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2011-02-03 12:29 [PATCHv2] Fix EDD3.0 data verification Gleb Natapov
2011-02-08 14:53 ` Gleb Natapov
2011-02-16 15:09   ` Gleb Natapov
2011-02-16 18:57     ` H. Peter Anvin
2011-03-16  8:57       ` Gleb Natapov
2011-04-05 15:41         ` Gleb Natapov

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