@@ -2675,7 +2675,7 @@ static int do_setvfinfo(struct net_device *dev, struct nlattr **tb)
return err;
}
-static int do_set_master(struct net_device *dev, int ifindex,
+static int do_set_master(struct net_device *dev, struct net_device *master,
struct netlink_ext_ack *extack)
{
struct net_device *upper_dev = netdev_master_upper_dev_get(dev);
@@ -2683,7 +2683,7 @@ static int do_set_master(struct net_device *dev, int ifindex,
int err;
if (upper_dev) {
- if (upper_dev->ifindex == ifindex)
+ if (upper_dev == master)
return 0;
ops = upper_dev->netdev_ops;
if (ops->ndo_del_slave) {
@@ -2695,10 +2695,8 @@ static int do_set_master(struct net_device *dev, int ifindex,
}
}
- if (ifindex) {
- upper_dev = __dev_get_by_index(dev_net(dev), ifindex);
- if (!upper_dev)
- return -EINVAL;
+ if (master) {
+ upper_dev = master;
ops = upper_dev->netdev_ops;
if (ops->ndo_add_slave) {
err = ops->ndo_add_slave(upper_dev, dev, extack);
@@ -2775,7 +2773,8 @@ static int do_set_proto_down(struct net_device *dev,
/* notify flag means notify + modified. */
#define DO_SETLINK_NOTIFY 0x03
static int do_setlink(struct net *net, const struct sk_buff *skb,
- struct net_device *dev, struct ifinfomsg *ifm,
+ struct net_device *dev, struct net_device *master,
+ struct ifinfomsg *ifm,
struct netlink_ext_ack *extack,
struct nlattr **tb, int status)
{
@@ -2897,8 +2896,8 @@ static int do_setlink(struct net *net, const struct sk_buff *skb,
goto errout;
}
- if (tb[IFLA_MASTER]) {
- err = do_set_master(dev, nla_get_u32(tb[IFLA_MASTER]), extack);
+ if (master) {
+ err = do_set_master(dev, master, extack);
if (err)
goto errout;
status |= DO_SETLINK_MODIFIED;
@@ -3156,12 +3155,24 @@ static struct net_device *rtnl_dev_get(struct net *net,
return __dev_get_by_name(net, ifname);
}
+static struct net_device *rtnl_master_get(struct net *net, struct nlattr *tb[])
+{
+ struct net_device *master;
+
+ if (!tb[IFLA_MASTER])
+ return NULL;
+ master = __dev_get_by_index(net, nla_get_u32(tb[IFLA_MASTER]));
+ if (!master)
+ return ERR_PTR(-EINVAL);
+ return master;
+}
+
static int rtnl_setlink(struct sk_buff *skb, struct nlmsghdr *nlh,
struct netlink_ext_ack *extack)
{
struct net *net = sock_net(skb->sk);
struct ifinfomsg *ifm;
- struct net_device *dev;
+ struct net_device *dev, *master = NULL;
struct net *target_net = NULL;
int err;
struct nlattr *tb[IFLA_MAX+1];
@@ -3196,11 +3207,17 @@ static int rtnl_setlink(struct sk_buff *skb, struct nlmsghdr *nlh,
goto errout;
}
+ master = rtnl_master_get(target_net ? : net, tb);
+ if (IS_ERR(master)) {
+ err = -EINVAL;
+ goto errout;
+ }
+
err = validate_linkmsg(dev, tb, extack);
if (err < 0)
goto errout;
- err = do_setlink(target_net, skb, dev, ifm, extack, tb, 0);
+ err = do_setlink(target_net, skb, dev, master, ifm, extack, tb, 0);
errout:
if (target_net)
put_net(target_net);
@@ -3440,7 +3457,7 @@ static int rtnl_group_changelink(const struct sk_buff *skb,
struct netlink_ext_ack *extack,
struct nlattr **tb)
{
- struct net_device *dev, *aux;
+ struct net_device *dev, *aux, *master = NULL;
struct net *target_net;
int err;
@@ -3451,12 +3468,18 @@ static int rtnl_group_changelink(const struct sk_buff *skb,
goto out;
}
+ master = rtnl_master_get(target_net ? : net, tb);
+ if (IS_ERR(master)) {
+ err = -EINVAL;
+ goto out;
+ }
+
for_each_netdev_safe(net, dev, aux) {
if (dev->group == group) {
err = validate_linkmsg(dev, tb, extack);
if (err < 0)
break;
- err = do_setlink(target_net, skb, dev, ifm, extack, tb, 0);
+ err = do_setlink(target_net, skb, dev, master, ifm, extack, tb, 0);
if (err < 0)
break;
}
@@ -3478,7 +3501,7 @@ static int rtnl_newlink_create(struct sk_buff *skb, struct ifinfomsg *ifm,
struct net *net = sock_net(skb->sk);
u32 portid = NETLINK_CB(skb).portid;
struct net *link_net;
- struct net_device *dev;
+ struct net_device *dev, *master = NULL;
char ifname[IFNAMSIZ];
int err;
@@ -3519,6 +3542,12 @@ static int rtnl_newlink_create(struct sk_buff *skb, struct ifinfomsg *ifm,
dev->ifindex = ifm->ifi_index;
+ master = rtnl_master_get(link_net ? : dest_net, tb);
+ if (IS_ERR(master)) {
+ err = -EINVAL;
+ goto out;
+ }
+
if (ops->newlink)
err = ops->newlink(link_net ? : net, dev, tb, data, extack);
else
@@ -3536,8 +3565,8 @@ static int rtnl_newlink_create(struct sk_buff *skb, struct ifinfomsg *ifm,
if (err < 0)
goto out_unregister;
}
- if (tb[IFLA_MASTER]) {
- err = do_set_master(dev, nla_get_u32(tb[IFLA_MASTER]), extack);
+ if (master) {
+ err = do_set_master(dev, master, extack);
if (err)
goto out_unregister;
}
@@ -3567,6 +3596,7 @@ static int __rtnl_newlink_setlink(struct sk_buff *skb, struct nlmsghdr *nlh,
struct rtnl_newlink_tbs *tbs,
struct netlink_ext_ack *extack,
struct net *target_net, struct net_device *dev,
+ struct net_device *new_master,
const struct rtnl_link_ops *ops,
struct nlattr **linkinfo, struct nlattr **data)
{
@@ -3632,7 +3662,7 @@ static int __rtnl_newlink_setlink(struct sk_buff *skb, struct nlmsghdr *nlh,
status |= DO_SETLINK_NOTIFY;
}
- err = do_setlink(target_net, skb, dev, ifm, extack, tb, status);
+ err = do_setlink(target_net, skb, dev, new_master, ifm, extack, tb, status);
out:
return err;
}
@@ -3647,7 +3677,7 @@ static int __rtnl_newlink(struct sk_buff *skb, struct nlmsghdr *nlh,
struct net *net = sock_net(skb->sk);
const struct rtnl_link_ops *ops;
char kind[MODULE_NAME_LEN];
- struct net_device *dev;
+ struct net_device *dev, *new_master = NULL;
struct ifinfomsg *ifm;
struct nlattr **data;
bool link_specified;
@@ -3709,8 +3739,12 @@ static int __rtnl_newlink(struct sk_buff *skb, struct nlmsghdr *nlh,
}
if (dev) {
+ new_master = rtnl_master_get(target_net ? : net, tb);
+ if (IS_ERR(new_master))
+ return -EINVAL;
+
err = __rtnl_newlink_setlink(skb, nlh, tbs, extack,
- target_net, dev,
+ target_net, dev, new_master,
ops, linkinfo, data);
return err;
}
...to where main dev is dereferenced by ifi_index. The patch is preparation in rtnetlink code for using nd_lock. Having dereference of dev and master in same places allow to double lock them the same time. Signed-off-by: Kirill Tkhai <tkhai@ya.ru> --- net/core/rtnetlink.c | 72 +++++++++++++++++++++++++++++++++++++------------- 1 file changed, 53 insertions(+), 19 deletions(-)