| From 3033ddb70d07e77f3cd3f0950866182b22788113 Mon Sep 17 00:00:00 2001 |
| From: Sasha Levin <sashal@kernel.org> |
| Date: Wed, 18 Sep 2024 14:06:02 +0000 |
| Subject: bonding: Fix unnecessary warnings and logs from |
| bond_xdp_get_xmit_slave() |
| |
| From: Jiwon Kim <jiwonaid0@gmail.com> |
| |
| [ Upstream commit 0cbfd45fbcf0cb26d85c981b91c62fe73cdee01c ] |
| |
| syzbot reported a WARNING in bond_xdp_get_xmit_slave. To reproduce |
| this[1], one bond device (bond1) has xdpdrv, which increases |
| bpf_master_redirect_enabled_key. Another bond device (bond0) which is |
| unsupported by XDP but its slave (veth3) has xdpgeneric that returns |
| XDP_TX. This triggers WARN_ON_ONCE() from the xdp_master_redirect(). |
| To reduce unnecessary warnings and improve log management, we need to |
| delete the WARN_ON_ONCE() and add ratelimit to the netdev_err(). |
| |
| [1] Steps to reproduce: |
| # Needs tx_xdp with return XDP_TX; |
| ip l add veth0 type veth peer veth1 |
| ip l add veth3 type veth peer veth4 |
| ip l add bond0 type bond mode 6 # BOND_MODE_ALB, unsupported by XDP |
| ip l add bond1 type bond # BOND_MODE_ROUNDROBIN by default |
| ip l set veth0 master bond1 |
| ip l set bond1 up |
| # Increases bpf_master_redirect_enabled_key |
| ip l set dev bond1 xdpdrv object tx_xdp.o section xdp_tx |
| ip l set veth3 master bond0 |
| ip l set bond0 up |
| ip l set veth4 up |
| # Triggers WARN_ON_ONCE() from the xdp_master_redirect() |
| ip l set veth3 xdpgeneric object tx_xdp.o section xdp_tx |
| |
| 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> |
| Signed-off-by: Nikolay Aleksandrov <razor@blackwall.org> |
| Link: https://patch.msgid.link/20240918140602.18644-1-jiwonaid0@gmail.com |
| Signed-off-by: Paolo Abeni <pabeni@redhat.com> |
| Signed-off-by: Sasha Levin <sashal@kernel.org> |
| --- |
| drivers/net/bonding/bond_main.c | 6 +++--- |
| 1 file changed, 3 insertions(+), 3 deletions(-) |
| |
| diff --git a/drivers/net/bonding/bond_main.c b/drivers/net/bonding/bond_main.c |
| index 60db34095a255..3c61f5fbe6b7f 100644 |
| --- a/drivers/net/bonding/bond_main.c |
| +++ b/drivers/net/bonding/bond_main.c |
| @@ -5536,9 +5536,9 @@ bond_xdp_get_xmit_slave(struct net_device *bond_dev, struct xdp_buff *xdp) |
| break; |
| |
| default: |
| - /* Should never happen. Mode guarded by bond_xdp_check() */ |
| - netdev_err(bond_dev, "Unknown bonding mode %d for xdp xmit\n", BOND_MODE(bond)); |
| - WARN_ON_ONCE(1); |
| + if (net_ratelimit()) |
| + netdev_err(bond_dev, "Unknown bonding mode %d for xdp xmit\n", |
| + BOND_MODE(bond)); |
| return NULL; |
| } |
| |
| -- |
| 2.43.0 |
| |
