From 94375f3e1d8970d7f1cf2681f9eb3204328360ca Mon Sep 17 00:00:00 2001
From: Cong Wang <xiyou.wangcong@gmail.com>
Date: Mon, 27 Nov 2017 11:15:16 -0800
Subject: [PATCH 01/19] xfrm: check id proto in validate_tmpl()
Git-commit: 6a53b7593233ab9e4f96873ebacc0f653a55c3e1
Patch-mainline: v4.15-rc6 
References: git-fixes

syzbot reported a kernel warning in xfrm_state_fini(), which
indicates that we have entries left in the list
net->xfrm.state_all whose proto is zero. And
xfrm_id_proto_match() doesn't consider them as a match with
IPSEC_PROTO_ANY in this case.

Proto with value 0 is probably not a valid value, at least
verify_newsa_info() doesn't consider it valid either.

This patch fixes it by checking the proto value in
validate_tmpl() and rejecting invalid ones, like what iproute2
does in xfrm_xfrmproto_getbyname().

Reported-by: syzbot <syzkaller@googlegroups.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>
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
Acked-by: Denis Kirjanov <dkirjanov@suse.com>
---
 net/xfrm/xfrm_user.c | 15 +++++++++++++++
 1 file changed, 15 insertions(+)

diff --git a/net/xfrm/xfrm_user.c b/net/xfrm/xfrm_user.c
index 3502b68cfa2b..37e7ca7133f8 100644
--- a/net/xfrm/xfrm_user.c
+++ b/net/xfrm/xfrm_user.c
@@ -1435,6 +1435,20 @@ static int validate_tmpl(int nr, struct
 		default:
 			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:
+			return -EINVAL;
+		}
 	}
 
 	return 0;
-- 
2.16.4