From: Raghuram Chary J <raghuramchary.jallipalli@microchip.com>
Date: Tue, 27 Mar 2018 14:51:16 +0530
Subject: lan78xx: Crash in lan78xx_writ_reg (Workqueue: events
 lan78xx_deferred_multicast_write)
Git-commit: 2d2d99ec13f62d5d2cecb6169dfdb6bbe05356d0
Patch-mainline: v4.16
References: networking-stable-18_04_10

Description:
Crash was reported with syzkaller pointing to lan78xx_write_reg routine.

Root-cause:
Proper cleanup of workqueues and init/setup routines was not happening
in failure conditions.

Fix:
Handled the error conditions by cleaning up the queues and init/setup
routines.

Fixes: 55d7de9de6c3 ("Microchip's LAN7800 family USB 2/3 to 10/100/1000 Ethernet device driver")
Reported-by: Andrey Konovalov <andreyknvl@google.com>
Signed-off-by: Raghuram Chary J <raghuramchary.jallipalli@microchip.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
---
 drivers/net/usb/lan78xx.c |   23 +++++++++++++++++++++--
 1 file changed, 21 insertions(+), 2 deletions(-)

--- a/drivers/net/usb/lan78xx.c
+++ b/drivers/net/usb/lan78xx.c
@@ -2863,8 +2863,7 @@ static int lan78xx_bind(struct lan78xx_n
 	if (ret < 0) {
 		netdev_warn(dev->net,
 			    "lan78xx_setup_irq_domain() failed : %d", ret);
-		kfree(pdata);
-		return ret;
+		goto out1;
 	}
 
 	dev->net->hard_header_len += TX_OVERHEAD;
@@ -2872,14 +2871,32 @@ static int lan78xx_bind(struct lan78xx_n
 
 	/* Init all registers */
 	ret = lan78xx_reset(dev);
+	if (ret) {
+		netdev_warn(dev->net, "Registers INIT FAILED....");
+		goto out2;
+	}
 
 	ret = lan78xx_mdio_init(dev);
+	if (ret) {
+		netdev_warn(dev->net, "MDIO INIT FAILED.....");
+		goto out2;
+	}
 
 	dev->net->flags |= IFF_MULTICAST;
 
 	pdata->wol = WAKE_MAGIC;
 
 	return ret;
+
+out2:
+	lan78xx_remove_irq_domain(dev);
+
+out1:
+	netdev_warn(dev->net, "Bind routine FAILED");
+	cancel_work_sync(&pdata->set_multicast);
+	cancel_work_sync(&pdata->set_vlan);
+	kfree(pdata);
+	return ret;
 }
 
 static void lan78xx_unbind(struct lan78xx_net *dev, struct usb_interface *intf)
@@ -2891,6 +2908,8 @@ static void lan78xx_unbind(struct lan78x
 	lan78xx_remove_mdio(dev);
 
 	if (pdata) {
+		cancel_work_sync(&pdata->set_multicast);
+		cancel_work_sync(&pdata->set_vlan);
 		netif_dbg(dev, ifdown, dev->net, "free pdata");
 		kfree(pdata);
 		pdata = NULL;