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* Re: [PATCH 1/2] dmi_scan: Fix missing check for _DMI_ signature in smbios_present()
@ 2013-02-17  2:35 Zhenzhong Duan
  2013-02-17  5:57 ` tmhikaru
  0 siblings, 1 reply; 3+ messages in thread
From: Zhenzhong Duan @ 2013-02-17  2:35 UTC (permalink / raw)
  To: ben; +Cc: tmhikaru, linux-kernel


----- ben@decadent.org.uk wrote：

> Commit 9f9c9cbb6057 ('drivers/firmware/dmi_scan.c: fetch dmi version
> from SMBIOS if it exists') hoisted the check for "_DMI_" into
> dmi_scan_machine(), which means that we don't bother to check for
> "_DMI_" at offset 16 in an SMBIOS entry.  smbios_present() may also
> call dmi_present() for an address where we found "_SM_", if it failed
> further validation.
> 
> Check for "_DMI_" in smbios_present() before calling dmi_present().
> 
> Reported-by: Tim McGrath <tmhikaru@gmail.com>
> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
> Cc: stable <stable@vger.kernel.org>
> ---
> This has a memcmp() that wasn't in the previous version, so I've not
> included the Acked-by or Tested-by for that.
Yes, the further "_DMI_" check is needed.
Acked-by: Zhenzhong Duan <zhenzhong.duan@oracle.com>
> 
> Ben.
> 
>  drivers/firmware/dmi_scan.c |    5 ++---
>  1 file changed, 2 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/firmware/dmi_scan.c
> b/drivers/firmware/dmi_scan.c
> index 982f1f5..a86ccff 100644
> --- a/drivers/firmware/dmi_scan.c
> +++ b/drivers/firmware/dmi_scan.c
> @@ -442,7 +442,6 @@ static int __init dmi_present(const char __iomem
> *p)
>  static int __init smbios_present(const char __iomem *p)
>  {
>  	u8 buf[32];
> -	int offset = 0;
>  
>  	memcpy_fromio(buf, p, 32);
>  	if ((buf[5] < 32) && dmi_checksum(buf, buf[5])) {
> @@ -461,9 +460,9 @@ static int __init smbios_present(const char
> __iomem *p)
>  			dmi_ver = 0x0206;
>  			break;
>  		}
> -		offset = 16;
> +		return memcmp(q + 16, "_DMI_", 5) || dmi_present(p + 16);
>  	}
> -	return dmi_present(buf + offset);
> +	return 1;
>  }
>  
>  void __init dmi_scan_machine(void)

^ permalink raw reply	[flat|nested] 3+ messages in thread
* [PATCH 1/2] dmi_scan: Fix missing check for _DMI_ signature in smbios_present()
@ 2013-02-16 18:00 Ben Hutchings
  0 siblings, 0 replies; 3+ messages in thread
From: Ben Hutchings @ 2013-02-16 18:00 UTC (permalink / raw)
  To: linux-kernel; +Cc: Tim McGrath, Zhenzhong Duan

[-- Attachment #1: Type: text/plain, Size: 1523 bytes --]

Commit 9f9c9cbb6057 ('drivers/firmware/dmi_scan.c: fetch dmi version
from SMBIOS if it exists') hoisted the check for "_DMI_" into
dmi_scan_machine(), which means that we don't bother to check for
"_DMI_" at offset 16 in an SMBIOS entry.  smbios_present() may also
call dmi_present() for an address where we found "_SM_", if it failed
further validation.

Check for "_DMI_" in smbios_present() before calling dmi_present().

Reported-by: Tim McGrath <tmhikaru@gmail.com>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Cc: stable <stable@vger.kernel.org>
---
This has a memcmp() that wasn't in the previous version, so I've not
included the Acked-by or Tested-by for that.

Ben.

 drivers/firmware/dmi_scan.c |    5 ++---
 1 file changed, 2 insertions(+), 3 deletions(-)

diff --git a/drivers/firmware/dmi_scan.c b/drivers/firmware/dmi_scan.c
index 982f1f5..a86ccff 100644
--- a/drivers/firmware/dmi_scan.c
+++ b/drivers/firmware/dmi_scan.c
@@ -442,7 +442,6 @@ static int __init dmi_present(const char __iomem *p)
 static int __init smbios_present(const char __iomem *p)
 {
 	u8 buf[32];
-	int offset = 0;
 
 	memcpy_fromio(buf, p, 32);
 	if ((buf[5] < 32) && dmi_checksum(buf, buf[5])) {
@@ -461,9 +460,9 @@ static int __init smbios_present(const char __iomem *p)
 			dmi_ver = 0x0206;
 			break;
 		}
-		offset = 16;
+		return memcmp(q + 16, "_DMI_", 5) || dmi_present(p + 16);
 	}
-	return dmi_present(buf + offset);
+	return 1;
 }
 
 void __init dmi_scan_machine(void)


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^ permalink raw reply related	[flat|nested] 3+ messages in thread
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2013-02-17  2:35 [PATCH 1/2] dmi_scan: Fix missing check for _DMI_ signature in smbios_present() Zhenzhong Duan
2013-02-17  5:57 ` tmhikaru
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2013-02-16 18:00 Ben Hutchings

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