net: hold netdev instance lock during ioctl operations

Convert all ndo_eth_ioctl invocations to dev_eth_ioctl which does the
locking. Reflow some of the dev_siocxxx to drop else clause.

Cc: Saeed Mahameed <saeed@kernel.org>
Signed-off-by: Stanislav Fomichev <sdf@fomichev.me>
Link: https://patch.msgid.link/20250305163732.2766420-8-sdf@fomichev.me
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

drivers/net/bonding/bond_main.c

@@ -855,7 +855,6 @@ static int bond_check_dev_link(struct bonding *bond,
 			       struct net_device *slave_dev, int reporting)
 {
 	const struct net_device_ops *slave_ops = slave_dev->netdev_ops;
-	int (*ioctl)(struct net_device *, struct ifreq *, int);
 	struct ifreq ifr;
 	struct mii_ioctl_data *mii;
 
@@ -871,8 +870,7 @@ static int bond_check_dev_link(struct bonding *bond,
 			BMSR_LSTATUS : 0;
 
 	/* Ethtool can't be used, fallback to MII ioctls. */
-	ioctl = slave_ops->ndo_eth_ioctl;
+	if (slave_ops->ndo_eth_ioctl) {
-	if (ioctl) {
 		/* TODO: set pointer to correct ioctl on a per team member
 		 *       bases to make this more efficient. that is, once
 		 *       we determine the correct ioctl, we will always
@@ -888,9 +886,10 @@ static int bond_check_dev_link(struct bonding *bond,
 		/* Yes, the mii is overlaid on the ifreq.ifr_ifru */
 		strscpy_pad(ifr.ifr_name, slave_dev->name, IFNAMSIZ);
 		mii = if_mii(&ifr);
-		if (ioctl(slave_dev, &ifr, SIOCGMIIPHY) == 0) {
+
+		if (dev_eth_ioctl(slave_dev, &ifr, SIOCGMIIPHY) == 0) {
 			mii->reg_num = MII_BMSR;
-			if (ioctl(slave_dev, &ifr, SIOCGMIIREG) == 0)
+			if (dev_eth_ioctl(slave_dev, &ifr, SIOCGMIIREG) == 0)
 				return mii->val_out & BMSR_LSTATUS;
 		}
 	}

include/linux/netdevice.h

@@ -4229,6 +4229,8 @@ int put_user_ifreq(struct ifreq *ifr, void __user *arg);
 int dev_ioctl(struct net *net, unsigned int cmd, struct ifreq *ifr,
 		void __user *data, bool *need_copyout);
 int dev_ifconf(struct net *net, struct ifconf __user *ifc);
+int dev_eth_ioctl(struct net_device *dev,
+		  struct ifreq *ifr, unsigned int cmd);
 int generic_hwtstamp_get_lower(struct net_device *dev,
 			       struct kernel_hwtstamp_config *kernel_cfg);
 int generic_hwtstamp_set_lower(struct net_device *dev,
@@ -4251,6 +4253,7 @@ int netif_change_net_namespace(struct net_device *dev, struct net *net,
 int dev_change_net_namespace(struct net_device *dev, struct net *net,
 			     const char *pat);
 int __dev_set_mtu(struct net_device *, int);
+int netif_set_mtu(struct net_device *dev, int new_mtu);
 int dev_set_mtu(struct net_device *, int);
 int dev_pre_changeaddr_notify(struct net_device *dev, const char *addr,
 			      struct netlink_ext_ack *extack);

net/8021q/vlan_dev.c

@@ -377,7 +377,6 @@ static int vlan_hwtstamp_set(struct net_device *dev,
 static int vlan_dev_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd)
 {
 	struct net_device *real_dev = vlan_dev_priv(dev)->real_dev;
-	const struct net_device_ops *ops = real_dev->netdev_ops;
 	struct ifreq ifrr;
 	int err = -EOPNOTSUPP;
 
@@ -388,8 +387,7 @@ static int vlan_dev_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd)
 	case SIOCGMIIPHY:
 	case SIOCGMIIREG:
 	case SIOCSMIIREG:
-		if (netif_device_present(real_dev) && ops->ndo_eth_ioctl)
+		err = dev_eth_ioctl(real_dev, &ifrr, cmd);
-			err = ops->ndo_eth_ioctl(real_dev, &ifrr, cmd);
 		break;
 	}
 

net/core/dev.c

@@ -9522,7 +9522,7 @@ int netif_set_mtu_ext(struct net_device *dev, int new_mtu,
 	return err;
 }
 
-int dev_set_mtu(struct net_device *dev, int new_mtu)
+int netif_set_mtu(struct net_device *dev, int new_mtu)
 {
 	struct netlink_ext_ack extack;
 	int err;
@@ -9533,7 +9533,7 @@ int dev_set_mtu(struct net_device *dev, int new_mtu)
 		net_err_ratelimited("%s: %s\n", dev->name, extack._msg);
 	return err;
 }
-EXPORT_SYMBOL(dev_set_mtu);
+EXPORT_SYMBOL(netif_set_mtu);
 
 int netif_change_tx_queue_len(struct net_device *dev, unsigned long new_len)
 {

net/core/dev_api.c

@@ -222,3 +222,33 @@ void dev_close(struct net_device *dev)
 	netdev_unlock_ops(dev);
 }
 EXPORT_SYMBOL(dev_close);
+
+int dev_eth_ioctl(struct net_device *dev,
+		  struct ifreq *ifr, unsigned int cmd)
+{
+	const struct net_device_ops *ops = dev->netdev_ops;
+	int ret = -ENODEV;
+
+	if (!ops->ndo_eth_ioctl)
+		return -EOPNOTSUPP;
+
+	netdev_lock_ops(dev);
+	if (netif_device_present(dev))
+		ret = ops->ndo_eth_ioctl(dev, ifr, cmd);
+	netdev_unlock_ops(dev);
+
+	return ret;
+}
+EXPORT_SYMBOL(dev_eth_ioctl);
+
+int dev_set_mtu(struct net_device *dev, int new_mtu)
+{
+	int ret;
+
+	netdev_lock_ops(dev);
+	ret = netif_set_mtu(dev, new_mtu);
+	netdev_unlock_ops(dev);
+
+	return ret;
+}
+EXPORT_SYMBOL(dev_set_mtu);

net/core/dev_ioctl.c

@@ -110,7 +110,7 @@ static int dev_getifmap(struct net_device *dev, struct ifreq *ifr)
 	return 0;
 }
 
-static int dev_setifmap(struct net_device *dev, struct ifreq *ifr)
+static int netif_setifmap(struct net_device *dev, struct ifreq *ifr)
 {
 	struct compat_ifmap *cifmap = (struct compat_ifmap *)&ifr->ifr_map;
 
@@ -240,20 +240,6 @@ int net_hwtstamp_validate(const struct kernel_hwtstamp_config *cfg)
 	return 0;
 }
 
-static int dev_eth_ioctl(struct net_device *dev,
-			 struct ifreq *ifr, unsigned int cmd)
-{
-	const struct net_device_ops *ops = dev->netdev_ops;
-
-	if (!ops->ndo_eth_ioctl)
-		return -EOPNOTSUPP;
-
-	if (!netif_device_present(dev))
-		return -ENODEV;
-
-	return ops->ndo_eth_ioctl(dev, ifr, cmd);
-}
-
 /**
  * dev_get_hwtstamp_phylib() - Get hardware timestamping settings of NIC
  *	or of attached phylib PHY
@@ -305,7 +291,9 @@ static int dev_get_hwtstamp(struct net_device *dev, struct ifreq *ifr)
 		return -ENODEV;
 
 	kernel_cfg.ifr = ifr;
+	netdev_lock_ops(dev);
 	err = dev_get_hwtstamp_phylib(dev, &kernel_cfg);
+	netdev_unlock_ops(dev);
 	if (err)
 		return err;
 
@@ -429,7 +417,9 @@ static int dev_set_hwtstamp(struct net_device *dev, struct ifreq *ifr)
 	if (!netif_device_present(dev))
 		return -ENODEV;
 
+	netdev_lock_ops(dev);
 	err = dev_set_hwtstamp_phylib(dev, &kernel_cfg, &extack);
+	netdev_unlock_ops(dev);
 	if (err)
 		return err;
 
@@ -504,10 +494,14 @@ static int dev_siocbond(struct net_device *dev,
 	const struct net_device_ops *ops = dev->netdev_ops;
 
 	if (ops->ndo_siocbond) {
+		int ret = -ENODEV;
+
+		netdev_lock_ops(dev);
 		if (netif_device_present(dev))
-			return ops->ndo_siocbond(dev, ifr, cmd);
+			ret = ops->ndo_siocbond(dev, ifr, cmd);
-		else
+		netdev_unlock_ops(dev);
-			return -ENODEV;
+
+		return ret;
 	}
 
 	return -EOPNOTSUPP;
@@ -519,10 +513,14 @@ static int dev_siocdevprivate(struct net_device *dev, struct ifreq *ifr,
 	const struct net_device_ops *ops = dev->netdev_ops;
 
 	if (ops->ndo_siocdevprivate) {
+		int ret = -ENODEV;
+
+		netdev_lock_ops(dev);
 		if (netif_device_present(dev))
-			return ops->ndo_siocdevprivate(dev, ifr, data, cmd);
+			ret = ops->ndo_siocdevprivate(dev, ifr, data, cmd);
-		else
+		netdev_unlock_ops(dev);
-			return -ENODEV;
+
+		return ret;
 	}
 
 	return -EOPNOTSUPP;
@@ -533,10 +531,14 @@ static int dev_siocwandev(struct net_device *dev, struct if_settings *ifs)
 	const struct net_device_ops *ops = dev->netdev_ops;
 
 	if (ops->ndo_siocwandev) {
+		int ret = -ENODEV;
+
+		netdev_lock_ops(dev);
 		if (netif_device_present(dev))
-			return ops->ndo_siocwandev(dev, ifs);
+			ret = ops->ndo_siocwandev(dev, ifs);
-		else
+		netdev_unlock_ops(dev);
-			return -ENODEV;
+
+		return ret;
 	}
 
 	return -EOPNOTSUPP;
@@ -580,11 +582,16 @@ static int dev_ifsioc(struct net *net, struct ifreq *ifr, void __user *data,
 		memcpy(dev->broadcast, ifr->ifr_hwaddr.sa_data,
 		       min(sizeof(ifr->ifr_hwaddr.sa_data_min),
 			   (size_t)dev->addr_len));
+		netdev_lock_ops(dev);
 		call_netdevice_notifiers(NETDEV_CHANGEADDR, dev);
+		netdev_unlock_ops(dev);
 		return 0;
 
 	case SIOCSIFMAP:
-		return dev_setifmap(dev, ifr);
+		netdev_lock_ops(dev);
+		err = netif_setifmap(dev, ifr);
+		netdev_unlock_ops(dev);
+		return err;
 
 	case SIOCADDMULTI:
 		if (!ops->ndo_set_rx_mode ||
@@ -592,7 +599,10 @@ static int dev_ifsioc(struct net *net, struct ifreq *ifr, void __user *data,
 			return -EINVAL;
 		if (!netif_device_present(dev))
 			return -ENODEV;
-		return dev_mc_add_global(dev, ifr->ifr_hwaddr.sa_data);
+		netdev_lock_ops(dev);
+		err = dev_mc_add_global(dev, ifr->ifr_hwaddr.sa_data);
+		netdev_unlock_ops(dev);
+		return err;
 
 	case SIOCDELMULTI:
 		if (!ops->ndo_set_rx_mode ||
@@ -600,7 +610,10 @@ static int dev_ifsioc(struct net *net, struct ifreq *ifr, void __user *data,
 			return -EINVAL;
 		if (!netif_device_present(dev))
 			return -ENODEV;
-		return dev_mc_del_global(dev, ifr->ifr_hwaddr.sa_data);
+		netdev_lock_ops(dev);
+		err = dev_mc_del_global(dev, ifr->ifr_hwaddr.sa_data);
+		netdev_unlock_ops(dev);
+		return err;
 
 	case SIOCSIFTXQLEN:
 		if (ifr->ifr_qlen < 0)