From 8fc3672a8ad3e782bac80e979bc2a2c10960cbe9 Mon Sep 17 00:00:00 2001
From: Lijun Pan <ljp@linux.ibm.com>
Date: Tue, 27 Oct 2020 17:04:56 -0500
Subject: [PATCH] ibmvnic: fix ibmvnic_set_mac

References: bsc#1066382 ltc#160943 git-fixes
Patch-mainline: v5.10 or v5.10-rc2 (next release)
Git-commit: 8fc3672a8ad3e782bac80e979bc2a2c10960cbe9

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 validate ethernet address at the beginning of
ibmvnic_set_mac(), and move the ether_addr_copy to
the case of "adapter->state != VNIC_PROBED".

Fixes: c26eba03e407 ("ibmvnic: Update reset infrastructure to support tunable parameters")
Signed-off-by: Lijun Pan <ljp@linux.ibm.com>
Link: https://lore.kernel.org/r/20201027220456.71450-1-ljp@linux.ibm.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Acked-by: Michal Suchanek <msuchanek@suse.de>
---
 drivers/net/ethernet/ibm/ibmvnic.c | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/drivers/net/ethernet/ibm/ibmvnic.c b/drivers/net/ethernet/ibm/ibmvnic.c
index 8148f796a807..af4dfbe28d56 100644
--- a/drivers/net/ethernet/ibm/ibmvnic.c
+++ b/drivers/net/ethernet/ibm/ibmvnic.c
@@ -1815,9 +1815,13 @@ 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)
+	if (!is_valid_ether_addr(addr->sa_data))
+		return -EADDRNOTAVAIL;
+
+	if (adapter->state != VNIC_PROBED) {
+		ether_addr_copy(adapter->mac_addr, addr->sa_data);
 		rc = __ibmvnic_set_mac(netdev, addr->sa_data);
+	}
 
 	return rc;
 }
-- 
2.29.1