From ee201011c1e1563c114a55c86eb164b236f18e84 Mon Sep 17 00:00:00 2001
From: Stephen Suryaputra <ssuryaextr@gmail.com>
Date: Tue, 30 Nov 2021 11:26:37 -0500
Subject: vrf: Reset IPCB/IP6CB when processing outbound pkts in vrf dev xmit

IPCB/IP6CB need to be initialized when processing outbound v4 or v6 pkts
in the codepath of vrf device xmit function so that leftover garbage
doesn't cause futher code that uses the CB to incorrectly process the
pkt.

One occasion of the issue might occur when MPLS route uses the vrf
device as the outgoing device such as when the route is added using "ip
-f mpls route add <label> dev <vrf>" command.

The problems seems to exist since day one. Hence I put the day one
commits on the Fixes tags.

Fixes: 193125dbd8eb ("net: Introduce VRF device driver")
Fixes: 35402e313663 ("net: Add IPv6 support to VRF device")
Cc: stable@vger.kernel.org
Signed-off-by: Stephen Suryaputra <ssuryaextr@gmail.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Link: https://lore.kernel.org/r/20211130162637.3249-1-ssuryaextr@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
---
 drivers/net/vrf.c | 2 ++
 1 file changed, 2 insertions(+)

(limited to 'drivers/net/vrf.c')

diff --git a/drivers/net/vrf.c b/drivers/net/vrf.c
index ccf677015d5b..131c745dc701 100644
--- a/drivers/net/vrf.c
+++ b/drivers/net/vrf.c
@@ -497,6 +497,7 @@ static netdev_tx_t vrf_process_v6_outbound(struct sk_buff *skb,
 	/* strip the ethernet header added for pass through VRF device */
 	__skb_pull(skb, skb_network_offset(skb));
 
+	memset(IP6CB(skb), 0, sizeof(*IP6CB(skb)));
 	ret = vrf_ip6_local_out(net, skb->sk, skb);
 	if (unlikely(net_xmit_eval(ret)))
 		dev->stats.tx_errors++;
@@ -579,6 +580,7 @@ static netdev_tx_t vrf_process_v4_outbound(struct sk_buff *skb,
 					       RT_SCOPE_LINK);
 	}
 
+	memset(IPCB(skb), 0, sizeof(*IPCB(skb)));
 	ret = vrf_ip_local_out(dev_net(skb_dst(skb)->dev), skb->sk, skb);
 	if (unlikely(net_xmit_eval(ret)))
 		vrf_dev->stats.tx_errors++;
-- 
cgit