[PATCH net-next,v2] ipvs: orphan skb on LOCAL_IN path

[Alex Gartrell <agartrell@xxxxxx>]

skb->sk can be set in the early_demux path.  This can be problematic, as it
may be a time-wait socket, which will blow up in the ip6_output path when
we try to pull out the non-existant pinet6 pointer (the type-punning causes
that pointer to be garbage).

This patch orphans the skb if it's not a local socket, so we no longer have
to worry about running into the time-wait problem from early demux.  It
does this by checking for dev, which is unset in that path.

Signed-off-by: Alex Gartrell <agartrell@xxxxxx>
---
 net/netfilter/ipvs/ip_vs_xmit.c | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/net/netfilter/ipvs/ip_vs_xmit.c b/net/netfilter/ipvs/ip_vs_xmit.c
index 936fd29..9b8c3c4 100644
--- a/net/netfilter/ipvs/ip_vs_xmit.c
+++ b/net/netfilter/ipvs/ip_vs_xmit.c
@@ -484,6 +484,9 @@ static inline int ip_vs_tunnel_xmit_prepare(struct sk_buff 
*skb,
        if (unlikely(cp->flags & IP_VS_CONN_F_NFCT))
                ret = ip_vs_confirm_conntrack(skb);
        if (ret == NF_ACCEPT) {
+               /* orphan on LOCAL_IN */
+               if (skb->dev)
+                       skb_orphan(skb);
                nf_reset(skb);
                skb_forward_csum(skb);
        }
@@ -502,6 +505,9 @@ static inline int ip_vs_nat_send_or_cont(int pf, struct 
sk_buff *skb,
        else
                ip_vs_update_conntrack(skb, cp, 1);
        if (!local) {
+               /* orphan on LOCAL_IN */
+               if (skb->dev)
+                       skb_orphan(skb);
                skb_forward_csum(skb);
                NF_HOOK(pf, NF_INET_LOCAL_OUT, skb, NULL, skb_dst(skb)->dev,
                        dst_output);
@@ -520,6 +526,9 @@ static inline int ip_vs_send_or_cont(int pf, struct sk_buff 
*skb,
        if (likely(!(cp->flags & IP_VS_CONN_F_NFCT)))
                ip_vs_notrack(skb);
        if (!local) {
+               /* orphan on LOCAL_IN */
+               if (skb->dev)
+                       skb_orphan(skb);
                skb_forward_csum(skb);
                NF_HOOK(pf, NF_INET_LOCAL_OUT, skb, NULL, skb_dst(skb)->dev,
                        dst_output);
-- 
Alex Gartrell <agartrell@xxxxxx>

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