[PATCH 4.9 22/28] s390/qeth: free netdevice when removing a card

Greg Kroah-Hartman
2018-03-29T18:00:41Z

From: Julian Wiedmann <jwi@linux.vnet.ibm.com>

[ Upstream commit 6be687395b3124f002a653c1a50b3260222b3cd7 ]

On removal, a qeth card's netdevice is currently not properly freed
because the call chain looks as follows:

qeth_core_remove_device(card)
lx_remove_device(card)
unregister_netdev(card->dev)
card->dev = NULL !!!
qeth_core_free_card(card)
if (card->dev) !!!
free_netdev(card->dev)

Fix it by free'ing the netdev straight after unregistering. This also
fixes the sysfs-driven layer switch case (qeth_dev_layer2_store()),
where the need to free the current netdevice was not considered at all.

Note that free_netdev() takes care of the netif_napi_del() for us too.

Fixes: 4a71df50047f ("qeth: new qeth device driver")
Signed-off-by: Julian Wiedmann <jwi@linux.vnet.ibm.com>
Reviewed-by: Ursula Braun <ubraun@linux.vnet.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
drivers/s390/net/qeth_core_main.c | 2 --
drivers/s390/net/qeth_l2_main.c | 2 +-
drivers/s390/net/qeth_l3_main.c | 2 +-
3 files changed, 2 insertions(+), 4 deletions(-)

--- a/drivers/s390/net/qeth_core_main.c
+++ b/drivers/s390/net/qeth_core_main.c
@@ -4989,8 +4989,6 @@ static void qeth_core_free_card(struct q
QETH_DBF_HEX(SETUP, 2, &card, sizeof(void *));
qeth_clean_channel(&card->read);
qeth_clean_channel(&card->write);
- if (card->dev)
- free_netdev(card->dev);
qeth_free_qdio_buffers(card);
unregister_service_level(&card->qeth_service_level);
kfree(card);
--- a/drivers/s390/net/qeth_l2_main.c
+++ b/drivers/s390/net/qeth_l2_main.c
@@ -1057,8 +1057,8 @@ static void qeth_l2_remove_device(struct
qeth_l2_set_offline(cgdev);

if (card->dev) {
- netif_napi_del(&card->napi);
unregister_netdev(card->dev);
+ free_netdev(card->dev);
card->dev = NULL;
}
return;
--- a/drivers/s390/net/qeth_l3_main.c
+++ b/drivers/s390/net/qeth_l3_main.c
@@ -3192,8 +3192,8 @@ static void qeth_l3_remove_device(struct
qeth_l3_set_offline(cgdev);

if (card->dev) {
- netif_napi_del(&card->napi);
unregister_netdev(card->dev);
+ free_netdev(card->dev);
card->dev = NULL;
}