netdev - [PATCH net] ibmvnic: no need to update adapter->mac

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Date:   Tue, 20 Oct 2020 18:28:12 -0500
From:   Lijun Pan <ljp@...ux.ibm.com>
To:     netdev@...r.kernel.org
Cc:     Lijun Pan <ljp@...ux.ibm.com>, Jakub Kicinski <kuba@...nel.org>
Subject: [PATCH net] ibmvnic: no need to update adapter->mac_addr before it completes

Jakub Kicinski brought up a concern in ibmvnic_set_mac().
ibmvnic_set_mac() does this:

	ether_addr_copy(adapter->mac_addr, addr->sa_data);
	if (adapter->state != VNIC_PROBED)
		rc = __ibmvnic_set_mac(netdev, addr->sa_data);

So if state == VNIC_PROBED, the user can assign an invalid address to
adapter->mac_addr, and ibmvnic_set_mac() will still return 0.

The fix is to not update adapter->mac_addr in ibmvnic_set_mac
and the error path of __ibmvnic_set_mac, and to update adpater->mac_addr
in handle_change_mac_rsp after the change mac request is completed in
VIOS.

Fixes: 62740e97881c ("net/ibmvnic: Update MAC address settings after adapter reset")
Cc: Jakub Kicinski <kuba@...nel.org>
Signed-off-by: Lijun Pan <ljp@...ux.ibm.com>
---
 drivers/net/ethernet/ibm/ibmvnic.c | 2 --
 1 file changed, 2 deletions(-)

diff --git a/drivers/net/ethernet/ibm/ibmvnic.c b/drivers/net/ethernet/ibm/ibmvnic.c
index 4dd3625a4fbc..c4c2b0e453fc 100644
--- a/drivers/net/ethernet/ibm/ibmvnic.c
+++ b/drivers/net/ethernet/ibm/ibmvnic.c
@@ -1817,7 +1817,6 @@ static int __ibmvnic_set_mac(struct net_device *netdev, u8 *dev_addr)
 	mutex_unlock(&adapter->fw_lock);
 	return 0;
 err:
-	ether_addr_copy(adapter->mac_addr, netdev->dev_addr);
 	return rc;
 }
 
@@ -1828,7 +1827,6 @@ static int ibmvnic_set_mac(struct net_device *netdev, void *p)
 	int rc;
 
 	rc = 0;
-	ether_addr_copy(adapter->mac_addr, addr->sa_data);
 	if (adapter->state != VNIC_PROBED)
 		rc = __ibmvnic_set_mac(netdev, addr->sa_data);
 
-- 
2.23.0