4.20-stable review patch. If anyone has any objections, please let me know.
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[ 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 --- drivers/s390/net/qeth_core.h | 1 + drivers/s390/net/qeth_l2_main.c | 2 ++ drivers/s390/net/qeth_l3_main.c | 1 + 3 files changed, 4 insertions(+)
diff --git a/drivers/s390/net/qeth_core.h b/drivers/s390/net/qeth_core.h index 99af1a0a3314..8999be74c545 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 8d3601891c62..49fa09c67d49 100644 --- a/drivers/s390/net/qeth_l2_main.c +++ b/drivers/s390/net/qeth_l2_main.c @@ -823,6 +823,8 @@ 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 f08b745c2007..d1bf55b5c8e1 100644 --- a/drivers/s390/net/qeth_l3_main.c +++ b/drivers/s390/net/qeth_l3_main.c @@ -2428,6 +2428,7 @@ 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);