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: 0f54761 ("qeth: Support VEPA mode") Signed-off-by: Julian Wiedmann <[email protected]> Signed-off-by: David S. Miller <[email protected]> Signed-off-by: Sasha Levin <[email protected]>
akeromi · Mar 13, 2019 · 825e58b · 825e58b
1 parent 5327c55
commit 825e58b
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diff --git 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
@@ -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
@@ -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);