[PATCH 4.4 090/131] dccp: do not use ipv6 header for ipv4 flow

From: Greg Kroah-Hartman
Date: Mon Apr 01 2019 - 13:34:09 EST


4.4-stable review patch. If anyone has any objections, please let me know.

------------------

From: Eric Dumazet <edumazet@xxxxxxxxxx>

[ Upstream commit e0aa67709f89d08c8d8e5bdd9e0b649df61d0090 ]

When a dual stack dccp listener accepts an ipv4 flow,
it should not attempt to use an ipv6 header or
inet6_iif() helper.

Fixes: 3df80d9320bc ("[DCCP]: Introduce DCCPv6")
Signed-off-by: Eric Dumazet <edumazet@xxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
net/dccp/ipv6.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

--- a/net/dccp/ipv6.c
+++ b/net/dccp/ipv6.c
@@ -427,8 +427,8 @@ static struct sock *dccp_v6_request_recv
newnp->ipv6_mc_list = NULL;
newnp->ipv6_ac_list = NULL;
newnp->ipv6_fl_list = NULL;
- newnp->mcast_oif = inet6_iif(skb);
- newnp->mcast_hops = ipv6_hdr(skb)->hop_limit;
+ newnp->mcast_oif = inet_iif(skb);
+ newnp->mcast_hops = ip_hdr(skb)->ttl;

/*
* No need to charge this sock to the relevant IPv6 refcnt debug socks count