[PATCH] net: Don't allow to attach xdp if bond slave device's upper already has a program

[Feng zhou <zhoufeng.zf@xxxxxxxxxxxxx>]

From: Feng Zhou <zhoufeng.zf@xxxxxxxxxxxxx>

Cannot attach when an upper device already has a program, This
restriction is only for bond's slave devices, and should not be
accidentally injured for devices like eth0 and vxlan0.

Signed-off-by: Feng Zhou <zhoufeng.zf@xxxxxxxxxxxxx>
---
 net/core/dev.c | 10 ++++++----
 1 file changed, 6 insertions(+), 4 deletions(-)

diff --git a/net/core/dev.c b/net/core/dev.c
index 6ea1d20676fb..e1f87662376a 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -9501,10 +9501,12 @@ static int dev_xdp_attach(struct net_device *dev, struct netlink_ext_ack *extack
 	}
 
 	/* don't allow if an upper device already has a program */
-	netdev_for_each_upper_dev_rcu(dev, upper, iter) {
-		if (dev_xdp_prog_count(upper) > 0) {
-			NL_SET_ERR_MSG(extack, "Cannot attach when an upper device already has a program");
-			return -EEXIST;
+	if (netif_is_bond_slave(dev)) {
+		netdev_for_each_upper_dev_rcu(dev, upper, iter) {
+			if (dev_xdp_prog_count(upper) > 0) {
+				NL_SET_ERR_MSG(extack, "Cannot attach when an upper device already has a program");
+				return -EEXIST;
+			}
 		}
 	}
 
-- 
2.30.2