xfrm: check id proto in validate_tmpl()

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>

diff --git a/net/xfrm/xfrm_user.c b/net/xfrm/xfrm_user.c
index 983b023..c2cfcc6 100644 (file)
--- a/net/xfrm/xfrm_user.c
+++ b/net/xfrm/xfrm_user.c
@@ -1445,6 +1445,21 @@ static int validate_tmpl(int nr, struct xfrm_user_tmpl *ut, u16 family)
                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;