[PATCH AUTOSEL for 4.9 082/281] xfrm: fix state migration copy replay sequence numbers

[Sasha Levin]

From: Antony Antony <antony@xxxxxxxxxxx>

[ Upstream commit a486cd23661c9387fb076c3f6ae8b2aa9d20d54a ]

During xfrm migration copy replay and preplay sequence numbers
from the previous state.

Here is a tcpdump output showing the problem.
10.0.10.46 is running vanilla kernel, is the IKE/IPsec responder.
After the migration it sent wrong sequence number, reset to 1.
The migration is from 10.0.0.52 to 10.0.0.53.

IP 10.0.0.52.4500 > 10.0.10.46.4500: UDP-encap: ESP(spi=0x43ef462d,seq=0x7cf), length 136
IP 10.0.10.46.4500 > 10.0.0.52.4500: UDP-encap: ESP(spi=0xca1c282d,seq=0x7cf), length 136
IP 10.0.0.52.4500 > 10.0.10.46.4500: UDP-encap: ESP(spi=0x43ef462d,seq=0x7d0), length 136
IP 10.0.10.46.4500 > 10.0.0.52.4500: UDP-encap: ESP(spi=0xca1c282d,seq=0x7d0), length 136

IP 10.0.0.53.4500 > 10.0.10.46.4500: NONESP-encap: isakmp: child_sa  inf2[I]
IP 10.0.10.46.4500 > 10.0.0.53.4500: NONESP-encap: isakmp: child_sa  inf2[R]
IP 10.0.0.53.4500 > 10.0.10.46.4500: NONESP-encap: isakmp: child_sa  inf2[I]
IP 10.0.10.46.4500 > 10.0.0.53.4500: NONESP-encap: isakmp: child_sa  inf2[R]

IP 10.0.0.53.4500 > 10.0.10.46.4500: UDP-encap: ESP(spi=0x43ef462d,seq=0x7d1), length 136

NOTE: next sequence is wrong 0x1

IP 10.0.10.46.4500 > 10.0.0.53.4500: UDP-encap: ESP(spi=0xca1c282d,seq=0x1), length 136
IP 10.0.0.53.4500 > 10.0.10.46.4500: UDP-encap: ESP(spi=0x43ef462d,seq=0x7d2), length 136
IP 10.0.10.46.4500 > 10.0.0.53.4500: UDP-encap: ESP(spi=0xca1c282d,seq=0x2), length 136

Signed-off-by: Antony Antony <antony@xxxxxxxxxxx>
Reviewed-by: Richard Guy Briggs <rgb@xxxxxxxxxxxx>
Signed-off-by: Steffen Klassert <steffen.klassert@xxxxxxxxxxx>
Signed-off-by: Sasha Levin <alexander.levin@xxxxxxxxxxxxx>
---
 net/xfrm/xfrm_state.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/net/xfrm/xfrm_state.c b/net/xfrm/xfrm_state.c
index 419bf5d463bd..125282916f55 100644
--- a/net/xfrm/xfrm_state.c
+++ b/net/xfrm/xfrm_state.c
@@ -1246,6 +1246,8 @@ static struct xfrm_state *xfrm_state_clone(struct xfrm_state *orig)
 	x->curlft.add_time = orig->curlft.add_time;
 	x->km.state = orig->km.state;
 	x->km.seq = orig->km.seq;
+	x->replay = orig->replay;
+	x->preplay = orig->preplay;
 
 	return x;
 
-- 
2.14.1