From: Lijun Pan <ljp@linux.ibm.com>
Date: Tue, 27 Oct 2020 22:04:56 +0000 (-0500)
Subject: ibmvnic: fix ibmvnic_set_mac
X-Git-Tag: v5.8.18~33
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=d6f6e3f978853a180631b541072051509665694d;p=thirdparty%2Fkernel%2Fstable.git

ibmvnic: fix ibmvnic_set_mac

[ Upstream 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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---

diff --git a/drivers/net/ethernet/ibm/ibmvnic.c b/drivers/net/ethernet/ibm/ibmvnic.c
index 3e0aab04d86fb..f96bb3dab5a8b 100644
--- a/drivers/net/ethernet/ibm/ibmvnic.c
+++ b/drivers/net/ethernet/ibm/ibmvnic.c
@@ -1828,9 +1828,13 @@ 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;
 }