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 <nikolay@redhat.com>
Acked-by: Veaceslav Falico <vfalico@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/bonding/bond_sysfs.c b/drivers/net/bonding/bond_sysfs.c
index ce46776..4e386836 100644
--- a/drivers/net/bonding/bond_sysfs.c
+++ b/drivers/net/bonding/bond_sysfs.c
@@ -419,27 +419,33 @@
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,