From: nikolay@redhat.com Date: Fri, 6 Sep 2013 22:00:25 +0000 (+0200) Subject: bonding: fix store_arp_validate race with mode change X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=5c5038dc26bdc609022a897e15f9ccdd28402ad9;p=linux-beck.git bonding: fix store_arp_validate race with mode change We need to protect store_arp_validate via rtnl because it can race with mode changing and we can end up having arp_validate set in a mode different from active-backup. Signed-off-by: Nikolay Aleksandrov Acked-by: Veaceslav Falico Signed-off-by: David S. Miller --- diff --git a/drivers/net/bonding/bond_sysfs.c b/drivers/net/bonding/bond_sysfs.c index ce4677668e2c..4e386836d34f 100644 --- a/drivers/net/bonding/bond_sysfs.c +++ b/drivers/net/bonding/bond_sysfs.c @@ -419,27 +419,33 @@ static ssize_t bonding_store_arp_validate(struct device *d, struct device_attribute *attr, const char *buf, size_t count) { - int new_value; + int new_value, ret = count; struct bonding *bond = to_bond(d); + if (!rtnl_trylock()) + return restart_syscall(); new_value = bond_parse_parm(buf, arp_validate_tbl); if (new_value < 0) { pr_err("%s: Ignoring invalid arp_validate value %s\n", bond->dev->name, buf); - return -EINVAL; + ret = -EINVAL; + goto out; } if (new_value && (bond->params.mode != BOND_MODE_ACTIVEBACKUP)) { pr_err("%s: arp_validate only supported in active-backup mode.\n", bond->dev->name); - return -EINVAL; + ret = -EINVAL; + goto out; } pr_info("%s: setting arp_validate to %s (%d).\n", bond->dev->name, arp_validate_tbl[new_value].modename, new_value); bond->params.arp_validate = new_value; +out: + rtnl_unlock(); - return count; + return ret; } static DEVICE_ATTR(arp_validate, S_IRUGO | S_IWUSR, bonding_show_arp_validate,