ipvs: Always clear ipvs_property flag in skb_scrub_packet()

We found an issue when using bpf_redirect with ipvs NAT mode after
commit ff70202 ("dev_forward_skb: do not scrub skb mark within
the same name space"). Particularly, we use bpf_redirect to return
the skb directly back to the netif it comes from, i.e., xnet is
false in skb_scrub_packet(), and then ipvs_property is preserved
and SNAT is skipped in the rx path.

ipvs_property has been already cleared when netns is changed in
commit 2b5ec1a ("netfilter/ipvs: clear ipvs_property flag when
SKB net namespace changed"). This patch just clears it in spite of
netns.

Fixes: 2b5ec1a ("netfilter/ipvs: clear ipvs_property flag when SKB net namespace changed")
Signed-off-by: Philo Lu <[email protected]>
Acked-by: Julian Anastasov <[email protected]>
Link: https://patch.msgid.link/[email protected]
Signed-off-by: Paolo Abeni <[email protected]>

Author: LPhgh

net/core/skbuff.c

@@ -6033,11 +6033,11 @@ void skb_scrub_packet(struct sk_buff *skb, bool xnet)
 	skb->offload_fwd_mark = 0;
 	skb->offload_l3_fwd_mark = 0;
 #endif
+	ipvs_reset(skb);
 
 	if (!xnet)
 		return;
 
-	ipvs_reset(skb);
 	skb->mark = 0;
 	skb_clear_tstamp(skb);
 }