From: Julian Wiedmann <jwi@linux.ibm.com>
Subject: s390/qeth: cancel close_dev work before removing a card
Patch-mainline: v5.0-rc6
Git-commit: c2780c1a3fb724560b1d44f7976e0de17bf153c7
References: LTC#175898, bsc#1127561
Description: qeth: cancel close_dev work before removing a card
Symptom: Undefined behaviour, primarily when a device is notified
by HW that the connected switch port no longer supports
VEPA mode.
Problem: 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.
Solution: Make sure that the work is completed before freeing the card.
Reproduction: -
Upstream-Description:
s390/qeth: cancel close_dev work before removing a card
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: Julian Wiedmann <jwi@linux.ibm.com>
Acked-by: Denis Kirjanov <dkirjanov@suse.com>
---
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(+)
--- a/drivers/s390/net/qeth_core.h
+++ b/drivers/s390/net/qeth_core.h
@@ -21,6 +21,7 @@
#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>
--- 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
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);
}
--- a/drivers/s390/net/qeth_l3_main.c
+++ b/drivers/s390/net/qeth_l3_main.c
@@ -2474,6 +2474,7 @@ static void qeth_l3_remove_device(struct
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);