[PATCH][stable] b44 WOL setup: one-bit-off stack corruption kernel panic fix

[PATCH][stable] b44 WOL setup: one-bit-off stack corruption kernel panic fix

[Stanislav Brabec]

About 50% of shutdowns of b44 Ethernet adapter ends by kernel panic with
kernels compiled with stack-protector.

Checking b44_magic_pattern() return values, one call of
b44_magic_pattern() returns 127. It means, that set_bit(128, pmask) was
called on line 1509. It means that bit 0 of 17th byte of pmask was
overwritten. But pmask has only 16 bytes. Stack corruption happens.
 
It seems that set_bit() on line 1509 always writes one bit off.

The fix does not only solve the stack corruption, but also makes Wake On
LAN working on my onboard B44 on Asus A7V-333X mainboard.

It seems that this problem affects all kernel versions since commit
725ad800 on 2006-06-20.

Signed-off-by: Stanislav Brabec <sbrabec@suse.cz>

diff --git a/drivers/net/b44.c b/drivers/net/b44.c
index 2a91323..4869adb 100644
--- a/drivers/net/b44.c
+++ b/drivers/net/b44.c
@@ -1505,8 +1505,7 @@ static int b44_magic_pattern(u8 *macaddr, u8 *ppattern, u8 *pmask, int offset)
 		for (k = 0; k< ethaddr_bytes; k++) {
 			ppattern[offset + magicsync +
 				(j * ETH_ALEN) + k] = macaddr[k];
-			len++;
-			set_bit(len, (unsigned long *) pmask);
+			set_bit(len++, (unsigned long *) pmask);
 		}
 	}
 	return len - 1;


-- 
Best Regards / S pozdravem,

Stanislav Brabec
software developer
---------------------------------------------------------------------
SUSE LINUX, s. r. o.                          e-mail: sbrabec@suse.cz
Lihovarská 1060/12           tel: +420 284 028 966, +49 911 740538747
190 00 Praha 9                                  fax: +420 284 028 951
Czech Republic                                    http://www.suse.cz/

Re: [PATCH][stable] b44 WOL setup: one-bit-off stack corruption kernel panic fix

[Stanislav Brabec]

Stanislav Brabec wrote:
> About 50% of shutdowns of b44 Ethernet adapter ends by kernel panic with
> kernels compiled with stack-protector.
> 
> Checking b44_magic_pattern() return values, one call of
> b44_magic_pattern() returns 127. It means, that set_bit(128, pmask) was
> called on line 1509. It means that bit 0 of 17th byte of pmask was
> overwritten. But pmask has only 16 bytes. Stack corruption happens.
>  
> It seems that set_bit() on line 1509 always writes one bit off.
> 
> The fix does not only solve the stack corruption, but also makes Wake On
> LAN working on my onboard B44 on Asus A7V-333X mainboard.
> 
> It seems that this problem affects all kernel versions since commit
> 725ad800 on 2006-06-20.

stable@kernel.org may be interested as well. Adding Cc:.

Signed-off-by: Stanislav Brabec <sbrabec@suse.cz>
Cc: stable@kernel.org


diff --git a/drivers/net/b44.c b/drivers/net/b44.c
index 2a91323..4869adb 100644
--- a/drivers/net/b44.c
+++ b/drivers/net/b44.c
@@ -1505,8 +1505,7 @@ static int b44_magic_pattern(u8 *macaddr, u8 *ppattern, u8 *pmask, int offset)
 		for (k = 0; k< ethaddr_bytes; k++) {
 			ppattern[offset + magicsync +
 				(j * ETH_ALEN) + k] = macaddr[k];
-			len++;
-			set_bit(len, (unsigned long *) pmask);
+			set_bit(len++, (unsigned long *) pmask);
 		}
 	}
 	return len - 1;



-- 
Best Regards / S pozdravem,

Stanislav Brabec
software developer
---------------------------------------------------------------------
SUSE LINUX, s. r. o.                          e-mail: sbrabec@suse.cz
Lihovarská 1060/12           tel: +420 284 028 966, +49 911 740538747
190 00 Praha 9                                  fax: +420 284 028 951
Czech Republic                                    http://www.suse.cz/

Re: [PATCH][stable] b44 WOL setup: one-bit-off stack corruption kernel panic fix

[David Miller]

From: Stanislav Brabec <sbrabec@suse.cz>
Date: Wed, 02 Dec 2009 15:35:20 +0100

> Stanislav Brabec wrote:
>> About 50% of shutdowns of b44 Ethernet adapter ends by kernel panic with
>> kernels compiled with stack-protector.
>> 
>> Checking b44_magic_pattern() return values, one call of
>> b44_magic_pattern() returns 127. It means, that set_bit(128, pmask) was
>> called on line 1509. It means that bit 0 of 17th byte of pmask was
>> overwritten. But pmask has only 16 bytes. Stack corruption happens.
>>  
>> It seems that set_bit() on line 1509 always writes one bit off.
>> 
>> The fix does not only solve the stack corruption, but also makes Wake On
>> LAN working on my onboard B44 on Asus A7V-333X mainboard.
>> 
>> It seems that this problem affects all kernel versions since commit
>> 725ad800 on 2006-06-20.
> 
> stable@kernel.org may be interested as well. Adding Cc:.

netdev@vger.kernel.org is even more interested.  Please post all
networking patches CC:'d there so they get properly logged
and tracked in patchwork.

Thank you.

Re: [PATCH][stable] b44 WOL setup: one-bit-off stack corruption kernel panic fix

[Stanislav Brabec]

David Miller wrote:
> From: Stanislav Brabec <sbrabec@suse.cz>
> Date: Wed, 02 Dec 2009 15:35:20 +0100
> >> 
> >> It seems that this problem affects all kernel versions since commit
> >> 725ad800 on 2006-06-20.
> > 
> > stable@kernel.org may be interested as well. Adding Cc:.
> 
> netdev@vger.kernel.org is even more interested.  Please post all
> networking patches CC:'d there so they get properly logged
> and tracked in patchwork.

OK, sending again with another Cc::

About 50% of shutdowns of b44 Ethernet adapter ends by kernel panic with
kernels compiled with stack-protector.

Checking b44_magic_pattern() return values, one call of
b44_magic_pattern() returns 127. It means, that set_bit(128, pmask) was
called on line 1509. It means that bit 0 of 17th byte of pmask was
overwritten. But pmask has only 16 bytes. Stack corruption happens.
 
It seems that set_bit() on line 1509 always writes one bit off.

The fix does not only solve the stack corruption, but also makes Wake On
LAN working on my onboard B44 on Asus A7V-333X mainboard.

It seems that this problem affects all kernel versions since commit
725ad800 on 2006-06-20.

Signed-off-by: Stanislav Brabec <sbrabec@suse.cz>
Cc: netdev@vger.kernel.org
Cc: stable@kernel.org
Cc: Gary Zambrano <zambrano@broadcom.com>

diff --git a/drivers/net/b44.c b/drivers/net/b44.c
index 2a91323..4869adb 100644
--- a/drivers/net/b44.c
+++ b/drivers/net/b44.c
@@ -1505,8 +1505,7 @@ static int b44_magic_pattern(u8 *macaddr, u8 *ppattern, u8 *pmask, int offset)
                for (k = 0; k< ethaddr_bytes; k++) {
                        ppattern[offset + magicsync +
                                (j * ETH_ALEN) + k] = macaddr[k];
-                       len++;
-                       set_bit(len, (unsigned long *) pmask);
+                       set_bit(len++, (unsigned long *) pmask);
                }
        }
        return len - 1;


-- 
Best Regards / S pozdravem,

Stanislav Brabec
software developer
---------------------------------------------------------------------
SUSE LINUX, s. r. o.                          e-mail: sbrabec@suse.cz
Lihovarská 1060/12           tel: +420 284 028 966, +49 911 740538747
190 00 Praha 9                                  fax: +420 284 028 951
Czech Republic                                    http://www.suse.cz/

Re: [PATCH][stable] b44 WOL setup: one-bit-off stack corruption kernel panic fix

[David Miller]

From: Stanislav Brabec <sbrabec@suse.cz>
Date: Thu, 03 Dec 2009 15:56:28 +0100

> About 50% of shutdowns of b44 Ethernet adapter ends by kernel panic with
> kernels compiled with stack-protector.
> 
> Checking b44_magic_pattern() return values, one call of
> b44_magic_pattern() returns 127. It means, that set_bit(128, pmask) was
> called on line 1509. It means that bit 0 of 17th byte of pmask was
> overwritten. But pmask has only 16 bytes. Stack corruption happens.
>  
> It seems that set_bit() on line 1509 always writes one bit off.
> 
> The fix does not only solve the stack corruption, but also makes Wake On
> LAN working on my onboard B44 on Asus A7V-333X mainboard.
> 
> It seems that this problem affects all kernel versions since commit
> 725ad800 on 2006-06-20.
> 
> Signed-off-by: Stanislav Brabec <sbrabec@suse.cz>

Applied, thanks.