bonding: fix set mode race conditions

Changing the mode without any locking can result in multiple races (e.g.
upping a bond, enslaving/releasing). Depending on which race is hit the
impact can vary from incosistent bond state to kernel crash.
Use RTNL to synchronize the mode setting with the dangerous races.

Signed-off-by: Nikolay Aleksandrov <nikolay@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
nikolay@redhat.com 2013-05-18 01:18:28 +00:00 committed by David S. Miller
parent ff0102ee10
commit ea6836dd7e

View File

@ -316,6 +316,9 @@ static ssize_t bonding_store_mode(struct device *d,
int new_value, ret = count;
struct bonding *bond = to_bond(d);
if (!rtnl_trylock())
return restart_syscall();
if (bond->dev->flags & IFF_UP) {
pr_err("unable to update mode of %s because interface is up.\n",
bond->dev->name);
@ -352,6 +355,7 @@ static ssize_t bonding_store_mode(struct device *d,
bond->dev->name, bond_mode_tbl[new_value].modename,
new_value);
out:
rtnl_unlock();
return ret;
}
static DEVICE_ATTR(mode, S_IRUGO | S_IWUSR,