[PATCH 4.14 075/146] s390/qeth: lock IP table while applying takeover changes

[Greg Kroah-Hartman]

4.14-stable review patch.  If anyone has any objections, please let me know.

------------------

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


[ Upstream commit 8a03a3692b100d84785ee7a834e9215e304c9e00 ]

Modifying the flags of an IP addr object needs to be protected against
eg. concurrent removal of the same object from the IP table.

Fixes: 5f78e29ceebf ("qeth: optimize IP handling in rx_mode callback")
Signed-off-by: Julian Wiedmann <j...@linux.vnet.ibm.com>
Signed-off-by: David S. Miller <da...@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gre...@linuxfoundation.org>
---
 drivers/s390/net/qeth_l3_sys.c |    2 ++
 1 file changed, 2 insertions(+)

--- a/drivers/s390/net/qeth_l3_sys.c
+++ b/drivers/s390/net/qeth_l3_sys.c
@@ -395,6 +395,7 @@ static ssize_t qeth_l3_dev_ipato_enable_
                goto out;
        card->ipato.enabled = enable;
 
+       spin_lock_bh(&card->ip_lock);
        hash_for_each(card->ip_htable, i, addr, hnode) {
                if (addr->type != QETH_IP_TYPE_NORMAL)
                        continue;
@@ -403,6 +404,7 @@ static ssize_t qeth_l3_dev_ipato_enable_
                else if (qeth_l3_is_addr_covered_by_ipato(card, addr))
                        addr->set_flags |= QETH_IPA_SETIP_TAKEOVER_FLAG;
        }
+       spin_unlock_bh(&card->ip_lock);
 out:
        mutex_unlock(&card->conf_mutex);
        return rc ? rc : count;