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 970654f..2d1f6a5 100644 (file)
--- 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 76b2fba..b7513c5 100644 (file)
--- 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 b7f6a83..7f71ca0 100644 (file)
--- 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);