Patch "s390/qeth: free netdevice when removing a card" has been added to the 4.9-stable tree

Patch "s390/qeth: free netdevice when removing a card" has been added to the 4.9-stable tree

[gregkh]

This is a note to let you know that I've just added the patch titled

    s390/qeth: free netdevice when removing a card

to the 4.9-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     s390-qeth-free-netdevice-when-removing-a-card.patch
and it can be found in the queue-4.9 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@vger.kernel.org> know about it.


>From foo@baz Wed Mar 28 20:16:33 CEST 2018
From: Julian Wiedmann <jwi@linux.vnet.ibm.com>
Date: Tue, 20 Mar 2018 07:59:12 +0100
Subject: s390/qeth: free netdevice when removing a card

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;
 	}
 


Patches currently in stable-queue which might be from jwi@linux.vnet.ibm.com are

queue-4.9/s390-qeth-when-thread-completes-wake-up-all-waiters.patch
queue-4.9/s390-qeth-lock-read-device-while-queueing-next-buffer.patch
queue-4.9/net-iucv-free-memory-obtained-by-kzalloc.patch
queue-4.9/s390-qeth-on-channel-error-reject-further-cmd-requests.patch
queue-4.9/s390-qeth-free-netdevice-when-removing-a-card.patch