--- /dev/null
+From dbb2483b2a46fbaf833cfb5deb5ed9cace9c7399 Mon Sep 17 00:00:00 2001
+From: Cong Wang <xiyou.wangcong@gmail.com>
+Date: Fri, 22 Mar 2019 16:26:19 -0700
+Subject: xfrm: clean up xfrm protocol checks
+
+From: Cong Wang <xiyou.wangcong@gmail.com>
+
+commit dbb2483b2a46fbaf833cfb5deb5ed9cace9c7399 upstream.
+
+In commit 6a53b7593233 ("xfrm: check id proto in validate_tmpl()")
+I introduced a check for xfrm protocol, but according to Herbert
+IPSEC_PROTO_ANY should only be used as a wildcard for lookup, so
+it should be removed from validate_tmpl().
+
+And, IPSEC_PROTO_ANY is expected to only match 3 IPSec-specific
+protocols, this is why xfrm_state_flush() could still miss
+IPPROTO_ROUTING, which leads that those entries are left in
+net->xfrm.state_all before exit net. Fix this by replacing
+IPSEC_PROTO_ANY with zero.
+
+This patch also extracts the check from validate_tmpl() to
+xfrm_id_proto_valid() and uses it in parse_ipsecrequest().
+With this, no other protocols should be added into xfrm.
+
+Fixes: 6a53b7593233 ("xfrm: check id proto in validate_tmpl()")
+Reported-by: syzbot+0bf0519d6e0de15914fe@syzkaller.appspotmail.com
+Cc: Steffen Klassert <steffen.klassert@secunet.com>
+Cc: Herbert Xu <herbert@gondor.apana.org.au>
+Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
+Acked-by: Herbert Xu <herbert@gondor.apana.org.au>
+Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
+Signed-off-by: Zubin Mithra <zsm@chromium.org>
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+
+---
+ include/net/xfrm.h | 17 +++++++++++++++++
+ net/key/af_key.c | 4 +++-
+ net/xfrm/xfrm_state.c | 2 +-
+ net/xfrm/xfrm_user.c | 14 +-------------
+ 4 files changed, 22 insertions(+), 15 deletions(-)
+
+--- a/include/net/xfrm.h
++++ b/include/net/xfrm.h
+@@ -1301,6 +1301,23 @@ static inline int xfrm_state_kern(const
+ return atomic_read(&x->tunnel_users);
+ }
+
++static inline bool xfrm_id_proto_valid(u8 proto)
++{
++ switch (proto) {
++ case IPPROTO_AH:
++ case IPPROTO_ESP:
++ case IPPROTO_COMP:
++#if IS_ENABLED(CONFIG_IPV6)
++ case IPPROTO_ROUTING:
++ case IPPROTO_DSTOPTS:
++#endif
++ return true;
++ default:
++ return false;
++ }
++}
++
++/* IPSEC_PROTO_ANY only matches 3 IPsec protocols, 0 could match all. */
+ static inline int xfrm_id_proto_match(u8 proto, u8 userproto)
+ {
+ return (!userproto || proto == userproto ||
+--- a/net/key/af_key.c
++++ b/net/key/af_key.c
+@@ -1969,8 +1969,10 @@ parse_ipsecrequest(struct xfrm_policy *x
+
+ if (rq->sadb_x_ipsecrequest_mode == 0)
+ return -EINVAL;
++ if (!xfrm_id_proto_valid(rq->sadb_x_ipsecrequest_proto))
++ return -EINVAL;
+
+- t->id.proto = rq->sadb_x_ipsecrequest_proto; /* XXX check proto */
++ t->id.proto = rq->sadb_x_ipsecrequest_proto;
+ if ((mode = pfkey_mode_to_xfrm(rq->sadb_x_ipsecrequest_mode)) < 0)
+ return -EINVAL;
+ t->mode = mode;
+--- a/net/xfrm/xfrm_state.c
++++ b/net/xfrm/xfrm_state.c
+@@ -2133,7 +2133,7 @@ void xfrm_state_fini(struct net *net)
+ unsigned int sz;
+
+ flush_work(&net->xfrm.state_hash_work);
+- xfrm_state_flush(net, IPSEC_PROTO_ANY, false);
++ xfrm_state_flush(net, 0, false);
+ flush_work(&net->xfrm.state_gc_work);
+
+ WARN_ON(!list_empty(&net->xfrm.state_all));
+--- a/net/xfrm/xfrm_user.c
++++ b/net/xfrm/xfrm_user.c
+@@ -1448,20 +1448,8 @@ static int validate_tmpl(int nr, struct
+ return -EINVAL;
+ }
+
+- switch (ut[i].id.proto) {
+- case IPPROTO_AH:
+- case IPPROTO_ESP:
+- case IPPROTO_COMP:
+-#if IS_ENABLED(CONFIG_IPV6)
+- case IPPROTO_ROUTING:
+- case IPPROTO_DSTOPTS:
+-#endif
+- case IPSEC_PROTO_ANY:
+- break;
+- default:
++ if (!xfrm_id_proto_valid(ut[i].id.proto))
+ return -EINVAL;
+- }
+-
+ }
+
+ return 0;