lwtunnel: Validate RTA_ENCAP_TYPE attribute length
lwtunnel_valid_encap_type_attr is used to validate encap attributes
within a multipath route. Add length validation checking to the type.
lwtunnel_valid_encap_type_attr is called converting attributes to
fib{6,}_config struct which means it is used before fib_get_nhs,
ip6_route_multipath_add, and ip6_route_multipath_del - other
locations that use rtnh_ok and then nla_get_u16 on RTA_ENCAP_TYPE
attribute.
Fixes: 9ed59592e3e3 ("lwtunnel: fix autoload of lwt modules")
Signed-off-by: David Ahern <dsahern@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/ipv6/route.c b/net/ipv6/route.c
index b311c0b..d2ff8a7 100644
--- a/net/ipv6/route.c
+++ b/net/ipv6/route.c
@@ -5287,6 +5287,10 @@ static int ip6_route_multipath_add(struct fib6_config *cfg,
r_cfg.fc_flags |= RTF_GATEWAY;
}
r_cfg.fc_encap = nla_find(attrs, attrlen, RTA_ENCAP);
+
+ /* RTA_ENCAP_TYPE length checked in
+ * lwtunnel_valid_encap_type_attr
+ */
nla = nla_find(attrs, attrlen, RTA_ENCAP_TYPE);
if (nla)
r_cfg.fc_encap_type = nla_get_u16(nla);