Bonding: force user to add HWTSTAMP_FLAG_BONDED_PHC_INDEX when get/se…

…t HWTSTAMP When there is a failover, the PHC index of bond active interface will be changed. This may break the user space program if the author didn't aware. By setting this flag, the user should aware that the PHC index get/set by syscall is not stable. And the user space is able to deal with it. Without this flag, the kernel will reject the request forwarding to bonding. Reported-by: Jakub Kicinski <[email protected]> Fixes: 94dd016 ("bond: pass get_ts_info and SIOC[SG]HWTSTAMP ioctl to active device") Signed-off-by: Hangbin Liu <[email protected]> Signed-off-by: David S. Miller <[email protected]>
juliens · Dec 14, 2021 · 085d610 · 085d610
1 parent 9c9211a
commit 085d610
Showing 1 changed file with 21 additions and 12 deletions.
diff --git a/drivers/net/bonding/bond_main.c b/drivers/net/bonding/bond_main.c
@@ -4094,6 +4094,7 @@ static int bond_eth_ioctl(struct net_device *bond_dev, struct ifreq *ifr, int cm
 	struct mii_ioctl_data *mii = NULL;
 	const struct net_device_ops *ops;
 	struct net_device *real_dev;
+	struct hwtstamp_config cfg;
 	struct ifreq ifrr;
 	int res = 0;
 
@@ -4124,21 +4125,29 @@ static int bond_eth_ioctl(struct net_device *bond_dev, struct ifreq *ifr, int cm
 		break;
 	case SIOCSHWTSTAMP:
 	case SIOCGHWTSTAMP:
-		rcu_read_lock();
-		real_dev = bond_option_active_slave_get_rcu(bond);
-		rcu_read_unlock();
-		if (real_dev) {
-			strscpy_pad(ifrr.ifr_name, real_dev->name, IFNAMSIZ);
-			ifrr.ifr_ifru = ifr->ifr_ifru;
+		if (copy_from_user(&cfg, ifr->ifr_data, sizeof(cfg)))
+			return -EFAULT;
+
+		if (cfg.flags & HWTSTAMP_FLAG_BONDED_PHC_INDEX) {
+			rcu_read_lock();
+			real_dev = bond_option_active_slave_get_rcu(bond);
+			rcu_read_unlock();
+			if (real_dev) {
+				strscpy_pad(ifrr.ifr_name, real_dev->name, IFNAMSIZ);
+				ifrr.ifr_ifru = ifr->ifr_ifru;
+
+				ops = real_dev->netdev_ops;
+				if (netif_device_present(real_dev) && ops->ndo_eth_ioctl) {
+					res = ops->ndo_eth_ioctl(real_dev, &ifrr, cmd);
 
-			ops = real_dev->netdev_ops;
-			if (netif_device_present(real_dev) && ops->ndo_eth_ioctl)
-				res = ops->ndo_eth_ioctl(real_dev, &ifrr, cmd);
+					if (!res)
+						ifr->ifr_ifru = ifrr.ifr_ifru;
 
-			if (!res)
-				ifr->ifr_ifru = ifrr.ifr_ifru;
+					return res;
+				}
+			}
 		}
-		break;
+		fallthrough;
 	default:
 		res = -EOPNOTSUPP;
 	}