6.1-stable review patch. If anyone has any objections, please let me know.
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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 375412ce1ea5f..51d6cf0a3fb4e 100644 --- a/drivers/net/bonding/bond_main.c +++ b/drivers/net/bonding/bond_main.c @@ -5538,9 +5538,9 @@ 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; }