[PATCH 07/11] igb: Avoid uninitialized advertised variable in eee_set_cur

From: Andi Kleen <redacted>

eee_get_cur assumes that the output data is already zeroed. It can
read-modify-write the advertised field:

              if (ipcnfg & E1000_IPCNFG_EEE_100M_AN)
2594			edata->advertised |= ADVERTISED_100baseT_Full;

This is ok for the normal ethtool eee_get call, which always
zeroes the input data before.

But eee_set_cur also calls eee_get_cur and it did not zero the input
field. Later on it then compares agsinst the field, which can contain partial
stack garbage.

Zero the input field in eee_set_cur() too.

Cc: jeffrey.t.kirsher@intel.com
Cc: netdev@vger.kernel.org
Signed-off-by: Andi Kleen <redacted>
---
 drivers/net/ethernet/intel/igb/igb_ethtool.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/net/ethernet/intel/igb/igb_ethtool.c b/drivers/net/ethernet/intel/igb/igb_ethtool.c
index 48cbc83..41e37ff 100644
--- a/drivers/net/ethernet/intel/igb/igb_ethtool.c
+++ b/drivers/net/ethernet/intel/igb/igb_ethtool.c

@@ -2652,6 +2652,8 @@ static int igb_set_eee(struct net_device *netdev,
 	    (hw->phy.media_type != e1000_media_type_copper))
 		return -EOPNOTSUPP;
 
+	memset(&eee_curr, 0, sizeof(struct ethtool_eee));
+
 	ret_val = igb_get_eee(netdev, &eee_curr);
 	if (ret_val)
 		return ret_val;

-- 
1.8.3.1

ACK

Thanks,

Carolyn 

On Mon, 2013-09-30 at 13:29 -0700, Andi Kleen wrote:

From: Andi Kleen <redacted>

eee_get_cur assumes that the output data is already zeroed. It can
read-modify-write the advertised field:

              if (ipcnfg & E1000_IPCNFG_EEE_100M_AN)
2594                    edata->advertised |= ADVERTISED_100baseT_Full;

This is ok for the normal ethtool eee_get call, which always
zeroes the input data before.

But eee_set_cur also calls eee_get_cur and it did not zero the input
field. Later on it then compares agsinst the field, which can contain
partial
stack garbage.

Zero the input field in eee_set_cur() too.

Cc: jeffrey.t.kirsher@intel.com
Cc: netdev@vger.kernel.org
Signed-off-by: Andi Kleen <redacted>
---
 drivers/net/ethernet/intel/igb/igb_ethtool.c | 2 ++
 1 file changed, 2 insertions(+)

Acked-by: Jeff Kirsher <redacted>

From: Andi Kleen <redacted>
Date: Mon, 30 Sep 2013 13:29:08 -0700

From: Andi Kleen <redacted>

eee_get_cur assumes that the output data is already zeroed. It can
read-modify-write the advertised field:

              if (ipcnfg & E1000_IPCNFG_EEE_100M_AN)
2594			edata->advertised |= ADVERTISED_100baseT_Full;

This is ok for the normal ethtool eee_get call, which always
zeroes the input data before.

But eee_set_cur also calls eee_get_cur and it did not zero the input
field. Later on it then compares agsinst the field, which can contain partial
stack garbage.

Zero the input field in eee_set_cur() too.

Cc: jeffrey.t.kirsher@intel.com
Cc: netdev@vger.kernel.org
Signed-off-by: Andi Kleen <redacted>

Applied.