From: Julian Wiedmann <jwi@linux.ibm.com>
Date: Mon, 4 Feb 2019 16:40:08 +0000 (+0100)
Subject: s390/qeth: cancel close_dev work before removing a card
X-Git-Tag: rel_imx_4.19.35_1.1.0~5994
X-Git-Url: https://git.somdevices.com/?a=commitdiff_plain;h=825e58bc9800897edd21920d4fef6aee714039d4;p=linux.git

s390/qeth: cancel close_dev work before removing a card

[ Upstream commit c2780c1a3fb724560b1d44f7976e0de17bf153c7 ]

A card's close_dev work is scheduled on a driver-wide workqueue. If the
card is removed and freed while the work is still active, this causes a
use-after-free.
So make sure that the work is completed before freeing the card.

Fixes: 0f54761d167f ("qeth: Support VEPA mode")
Signed-off-by: Julian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---

diff --git a/drivers/s390/net/qeth_core.h b/drivers/s390/net/qeth_core.h
index 970654fcc48d..2d1f6a583641 100644
--- a/drivers/s390/net/qeth_core.h
+++ b/drivers/s390/net/qeth_core.h
@@ -22,6 +22,7 @@
 #include <linux/hashtable.h>
 #include <linux/ip.h>
 #include <linux/refcount.h>
+#include <linux/workqueue.h>
 
 #include <net/ipv6.h>
 #include <net/if_inet6.h>
diff --git a/drivers/s390/net/qeth_l2_main.c b/drivers/s390/net/qeth_l2_main.c
index 76b2fba5fba2..b7513c5848cf 100644
--- a/drivers/s390/net/qeth_l2_main.c
+++ b/drivers/s390/net/qeth_l2_main.c
@@ -854,6 +854,8 @@ static void qeth_l2_remove_device(struct ccwgroup_device *cgdev)
 
 	if (cgdev->state == CCWGROUP_ONLINE)
 		qeth_l2_set_offline(cgdev);
+
+	cancel_work_sync(&card->close_dev_work);
 	if (qeth_netdev_is_registered(card->dev))
 		unregister_netdev(card->dev);
 }
diff --git a/drivers/s390/net/qeth_l3_main.c b/drivers/s390/net/qeth_l3_main.c
index b7f6a8384543..7f71ca0d08e7 100644
--- a/drivers/s390/net/qeth_l3_main.c
+++ b/drivers/s390/net/qeth_l3_main.c
@@ -2611,6 +2611,7 @@ static void qeth_l3_remove_device(struct ccwgroup_device *cgdev)
 	if (cgdev->state == CCWGROUP_ONLINE)
 		qeth_l3_set_offline(cgdev);
 
+	cancel_work_sync(&card->close_dev_work);
 	if (qeth_netdev_is_registered(card->dev))
 		unregister_netdev(card->dev);
 	qeth_l3_clear_ip_htable(card, 0);