[PATCH net] bondig: Add bond_xdp_check for bond_xdp_xmit in bond_main.c

Jiwon Kim posted 1 patch 2 months, 2 weeks ago
drivers/net/bonding/bond_main.c | 33 ++++++++++++++++++---------------
1 file changed, 18 insertions(+), 15 deletions(-)
[PATCH net] bondig: Add bond_xdp_check for bond_xdp_xmit in bond_main.c
Posted by Jiwon Kim 2 months, 2 weeks ago
Add bond_xdp_check to ensure the bond interface is in a valid state.

syzbot reported WARNING in bond_xdp_get_xmit_slave.
In bond_xdp_get_xmit_slave, the comment says
/* Should never happen. Mode guarded by bond_xdp_check() */.
However, it does not check the status when entering bond_xdp_xmit.

Reported-by: syzbot+c187823a52ed505b2257@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=c187823a52ed505b2257
Fixes: 9e2ee5c7e7c3 ("net, bonding: Add XDP support to the bonding driver")
Signed-off-by: Jiwon Kim <jiwonaid0@gmail.com>
---
 drivers/net/bonding/bond_main.c | 33 ++++++++++++++++++---------------
 1 file changed, 18 insertions(+), 15 deletions(-)

diff --git a/drivers/net/bonding/bond_main.c b/drivers/net/bonding/bond_main.c
index bb9c3d6ef435..078c85070b86 100644
--- a/drivers/net/bonding/bond_main.c
+++ b/drivers/net/bonding/bond_main.c
@@ -5551,27 +5551,30 @@ bond_xdp_get_xmit_slave(struct net_device *bond_dev, struct xdp_buff *xdp)
 static int bond_xdp_xmit(struct net_device *bond_dev,
 			 int n, struct xdp_frame **frames, u32 flags)
 {
-	int nxmit, err = -ENXIO;
+	struct bonding *bond = netdev_priv(bond_dev);
+	int nxmit = 0, err = -ENXIO;
 
 	rcu_read_lock();
 
-	for (nxmit = 0; nxmit < n; nxmit++) {
-		struct xdp_frame *frame = frames[nxmit];
-		struct xdp_frame *frames1[] = {frame};
-		struct net_device *slave_dev;
-		struct xdp_buff xdp;
+	if (bond_xdp_check(bond)) {
+		for (nxmit = 0; nxmit < n; nxmit++) {
+			struct xdp_frame *frame = frames[nxmit];
+			struct xdp_frame *frames1[] = {frame};
+			struct net_device *slave_dev;
+			struct xdp_buff xdp;
 
-		xdp_convert_frame_to_buff(frame, &xdp);
+			xdp_convert_frame_to_buff(frame, &xdp);
 
-		slave_dev = bond_xdp_get_xmit_slave(bond_dev, &xdp);
-		if (!slave_dev) {
-			err = -ENXIO;
-			break;
-		}
+			slave_dev = bond_xdp_get_xmit_slave(bond_dev, &xdp);
+			if (!slave_dev) {
+				err = -ENXIO;
+				break;
+			}
 
-		err = slave_dev->netdev_ops->ndo_xdp_xmit(slave_dev, 1, frames1, flags);
-		if (err < 1)
-			break;
+			err = slave_dev->netdev_ops->ndo_xdp_xmit(slave_dev, 1, frames1, flags);
+			if (err < 1)
+				break;
+		}
 	}
 
 	rcu_read_unlock();
-- 
2.43.0