[PATCH 4.19 271/293] ibmvnic: check failover_pending in login response

[Greg Kroah-Hartman]

From: Sukadev Bhattiprolu <sukadev@xxxxxxxxxxxxx>

commit 273c29e944bda9a20a30c26cfc34c9a3f363280b upstream.

If a failover occurs before a login response is received, the login
response buffer maybe undefined. Check that there was no failover
before accessing the login response buffer.

Fixes: 032c5e82847a ("Driver for IBM System i/p VNIC protocol")
Signed-off-by: Sukadev Bhattiprolu <sukadev@xxxxxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
 drivers/net/ethernet/ibm/ibmvnic.c |    8 ++++++++
 1 file changed, 8 insertions(+)

--- a/drivers/net/ethernet/ibm/ibmvnic.c
+++ b/drivers/net/ethernet/ibm/ibmvnic.c
@@ -4038,6 +4038,14 @@ static int handle_login_rsp(union ibmvni
 		return 0;
 	}
 
+	if (adapter->failover_pending) {
+		adapter->init_done_rc = -EAGAIN;
+		netdev_dbg(netdev, "Failover pending, ignoring login response\n");
+		complete(&adapter->init_done);
+		/* login response buffer will be released on reset */
+		return 0;
+	}
+
 	netdev->mtu = adapter->req_mtu - ETH_HLEN;
 
 	netdev_dbg(adapter->netdev, "Login Response Buffer:\n");