dev: Hold rtnl_net_lock() for dev_ifsioc().

Basically, dev_ifsioc() operates on the passed single netns (except
for netdev notifier chains with lower/upper devices for which we will
need more changes).

Let's hold rtnl_net_lock() for dev_ifsioc().

Now that NETDEV_CHANGENAME is always triggered under rtnl_net_lock()
of the device's netns. (do_setlink() and dev_ifsioc())

Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Link: https://patch.msgid.link/20250115095545.52709-4-kuniyu@amazon.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

diff --git a/net/core/dev.c b/net/core/dev.c
index 32fcf54b779d0bb242ee07291617df012069d983..fe5f5855593db34cb4bc31e6a637b59b9041bb73 100644 (file)
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -1348,16 +1348,13 @@ static int dev_get_valid_name(struct net *net, struct net_device *dev,
  */
 int dev_change_name(struct net_device *dev, const char *newname)
 {
+       struct net *net = dev_net(dev);
        unsigned char old_assign_type;
        char oldname[IFNAMSIZ];
        int err = 0;
        int ret;
-       struct net *net;
-
-       ASSERT_RTNL();
-       BUG_ON(!dev_net(dev));
 
-       net = dev_net(dev);
+       ASSERT_RTNL_NET(net);
 
        if (!strncmp(newname, dev->name, IFNAMSIZ))
                return 0;

diff --git a/net/core/dev_ioctl.c b/net/core/dev_ioctl.c
index 087a57b7e4fab1b1d02fa07b99c69d4c59e2ad67..4c2098ac9d7243eded892759165e0f668741f50a 100644 (file)
--- a/net/core/dev_ioctl.c
+++ b/net/core/dev_ioctl.c
@@ -543,7 +543,7 @@ static int dev_siocwandev(struct net_device *dev, struct if_settings *ifs)
 }
 
 /*
- *     Perform the SIOCxIFxxx calls, inside rtnl_lock()
+ *     Perform the SIOCxIFxxx calls, inside rtnl_net_lock()
  */
 static int dev_ifsioc(struct net *net, struct ifreq *ifr, void __user *data,
                      unsigned int cmd)
@@ -620,11 +620,14 @@ static int dev_ifsioc(struct net *net, struct ifreq *ifr, void __user *data,
                        return -ENODEV;
                if (!netif_is_bridge_master(dev))
                        return -EOPNOTSUPP;
+
                netdev_hold(dev, &dev_tracker, GFP_KERNEL);
-               rtnl_unlock();
+               rtnl_net_unlock(net);
+
                err = br_ioctl_call(net, netdev_priv(dev), cmd, ifr, NULL);
+
                netdev_put(dev, &dev_tracker);
-               rtnl_lock();
+               rtnl_net_lock(net);
                return err;
 
        case SIOCDEVPRIVATE ... SIOCDEVPRIVATE + 15:
@@ -770,9 +773,11 @@ int dev_ioctl(struct net *net, unsigned int cmd, struct ifreq *ifr,
                dev_load(net, ifr->ifr_name);
                if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
                        return -EPERM;
-               rtnl_lock();
+
+               rtnl_net_lock(net);
                ret = dev_ifsioc(net, ifr, data, cmd);
-               rtnl_unlock();
+               rtnl_net_unlock(net);
+
                if (colon)
                        *colon = ':';
                return ret;
@@ -816,9 +821,11 @@ int dev_ioctl(struct net *net, unsigned int cmd, struct ifreq *ifr,
        case SIOCBONDSLAVEINFOQUERY:
        case SIOCBONDINFOQUERY:
                dev_load(net, ifr->ifr_name);
-               rtnl_lock();
+
+               rtnl_net_lock(net);
                ret = dev_ifsioc(net, ifr, data, cmd);
-               rtnl_unlock();
+               rtnl_net_unlock(net);
+
                if (need_copyout)
                        *need_copyout = false;
                return ret;
@@ -841,9 +848,10 @@ int dev_ioctl(struct net *net, unsigned int cmd, struct ifreq *ifr,
                    (cmd >= SIOCDEVPRIVATE &&
                     cmd <= SIOCDEVPRIVATE + 15)) {
                        dev_load(net, ifr->ifr_name);
-                       rtnl_lock();
+
+                       rtnl_net_lock(net);
                        ret = dev_ifsioc(net, ifr, data, cmd);
-                       rtnl_unlock();
+                       rtnl_net_unlock(net);
                        return ret;
                }
                return -ENOTTY;

diff --git a/net/core/rtnl_net_debug.c b/net/core/rtnl_net_debug.c
index f406045cbd0e60653af480270bc45928f9e92839..7ecd28cc1c225672752e21a3bc408f492bdeb3ce 100644 (file)
--- a/net/core/rtnl_net_debug.c
+++ b/net/core/rtnl_net_debug.c
@@ -27,7 +27,6 @@ static int rtnl_net_debug_event(struct notifier_block *nb,
        case NETDEV_CHANGEADDR:
        case NETDEV_PRE_CHANGEADDR:
        case NETDEV_GOING_DOWN:
-       case NETDEV_CHANGENAME:
        case NETDEV_FEAT_CHANGE:
        case NETDEV_BONDING_FAILOVER:
        case NETDEV_PRE_UP:
@@ -60,18 +59,10 @@ static int rtnl_net_debug_event(struct notifier_block *nb,
                ASSERT_RTNL();
                break;
 
-       /* Once an event fully supports RTNL_NET, move it here
-        * and remove "if (0)" below.
-        *
-        * case NETDEV_XXX:
-        *      ASSERT_RTNL_NET(net);
-        *      break;
-        */
-       }
-
-       /* Just to avoid unused-variable error for dev and net. */
-       if (0)
+       case NETDEV_CHANGENAME:
                ASSERT_RTNL_NET(net);
+               break;
+       }
 
        return NOTIFY_DONE;
 }