This is a note to let you know that I've just added the patch titled
ipv4: reset rt_iif for recirculated mcast/bcast out pkts
to the 4.14-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
ipv4-reset-rt_iif-for-recirculated-mcast-bcast-out-pkts.patch
and it can be found in the queue-4.14 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From 5b18f1289808fee5d04a7e6ecf200189f41a4db6 Mon Sep 17 00:00:00 2001
From: Stephen Suryaputra <ssuryaextr@xxxxxxxxx>
Date: Wed, 26 Jun 2019 02:21:16 -0400
Subject: ipv4: reset rt_iif for recirculated mcast/bcast out pkts
From: Stephen Suryaputra <ssuryaextr@xxxxxxxxx>
commit 5b18f1289808fee5d04a7e6ecf200189f41a4db6 upstream.
Multicast or broadcast egress packets have rt_iif set to the oif. These
packets might be recirculated back as input and lookup to the raw
sockets may fail because they are bound to the incoming interface
(skb_iif). If rt_iif is not zero, during the lookup, inet_iif() function
returns rt_iif instead of skb_iif. Hence, the lookup fails.
v2: Make it non vrf specific (David Ahern). Reword the changelog to
reflect it.
Signed-off-by: Stephen Suryaputra <ssuryaextr@xxxxxxxxx>
Reviewed-by: David Ahern <dsahern@xxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
include/net/route.h | 1 +
net/ipv4/ip_output.c | 12 ++++++++++++
net/ipv4/route.c | 33 +++++++++++++++++++++++++++++++++
3 files changed, 46 insertions(+)
--- a/include/net/route.h
+++ b/include/net/route.h
@@ -223,6 +223,7 @@ void ip_rt_get_source(u8 *src, struct sk
struct rtable *rt_dst_alloc(struct net_device *dev,
unsigned int flags, u16 type,
bool nopolicy, bool noxfrm, bool will_cache);
+struct rtable *rt_dst_clone(struct net_device *dev, struct rtable *rt);
struct in_ifaddr;
void fib_add_ifaddr(struct in_ifaddr *);
--- a/net/ipv4/ip_output.c
+++ b/net/ipv4/ip_output.c
@@ -320,6 +320,7 @@ static int ip_finish_output(struct net *
static int ip_mc_finish_output(struct net *net, struct sock *sk,
struct sk_buff *skb)
{
+ struct rtable *new_rt;
int ret;
ret = BPF_CGROUP_RUN_PROG_INET_EGRESS(sk, skb);
@@ -328,6 +329,17 @@ static int ip_mc_finish_output(struct ne
return ret;
}
+ /* Reset rt_iif so that inet_iif() will return skb->skb_iif. Setting
+ * this to non-zero causes ipi_ifindex in in_pktinfo to be overwritten,
+ * see ipv4_pktinfo_prepare().
+ */
+ new_rt = rt_dst_clone(net->loopback_dev, skb_rtable(skb));
+ if (new_rt) {
+ new_rt->rt_iif = 0;
+ skb_dst_drop(skb);
+ skb_dst_set(skb, &new_rt->dst);
+ }
+
return dev_loopback_xmit(net, sk, skb);
}
--- a/net/ipv4/route.c
+++ b/net/ipv4/route.c
@@ -1607,6 +1607,39 @@ struct rtable *rt_dst_alloc(struct net_d
}
EXPORT_SYMBOL(rt_dst_alloc);
+struct rtable *rt_dst_clone(struct net_device *dev, struct rtable *rt)
+{
+ struct rtable *new_rt;
+
+ new_rt = dst_alloc(&ipv4_dst_ops, dev, 1, DST_OBSOLETE_FORCE_CHK,
+ rt->dst.flags);
+
+ if (new_rt) {
+ new_rt->rt_genid = rt_genid_ipv4(dev_net(dev));
+ new_rt->rt_flags = rt->rt_flags;
+ new_rt->rt_type = rt->rt_type;
+ new_rt->rt_is_input = rt->rt_is_input;
+ new_rt->rt_iif = rt->rt_iif;
+ new_rt->rt_pmtu = rt->rt_pmtu;
+ new_rt->rt_mtu_locked = rt->rt_mtu_locked;
+ new_rt->rt_gw_family = rt->rt_gw_family;
+ if (rt->rt_gw_family == AF_INET)
+ new_rt->rt_gw4 = rt->rt_gw4;
+ else if (rt->rt_gw_family == AF_INET6)
+ new_rt->rt_gw6 = rt->rt_gw6;
+ INIT_LIST_HEAD(&new_rt->rt_uncached);
+
+ new_rt->dst.flags |= DST_HOST;
+ new_rt->dst.input = rt->dst.input;
+ new_rt->dst.output = rt->dst.output;
+ new_rt->dst.error = rt->dst.error;
+ new_rt->dst.lastuse = jiffies;
+ new_rt->dst.lwtstate = lwtstate_get(rt->dst.lwtstate);
+ }
+ return new_rt;
+}
+EXPORT_SYMBOL(rt_dst_clone);
+
/* called in rcu_read_lock() section */
int ip_mc_validate_source(struct sk_buff *skb, __be32 daddr, __be32 saddr,
u8 tos, struct net_device *dev,
Patches currently in stable-queue which might be from ssuryaextr@xxxxxxxxx are
queue-4.14/ipv4-reset-rt_iif-for-recirculated-mcast-bcast-out-pkts.patch
