[PATCH AUTOSEL 4.14 225/371] mpls: fix warning with multi-label encap

Sasha Levin
2020-01-16T18:21:37Z

From: George Wilkie <gwilkie@vyatta.att-mail.com>

[ Upstream commit 2f3f7d1fa0d1039b24a55d127ed190f196fc3e79 ]

If you configure a route with multiple labels, e.g.
ip route add 10.10.3.0/24 encap mpls 16/100 via 10.10.2.2 dev ens4
A warning is logged:
kernel: [ 130.561819] netlink: 'ip': attribute type 1 has an invalid
length.

This happens because mpls_iptunnel_policy has set the type of
MPLS_IPTUNNEL_DST to fixed size NLA_U32.
Change it to a minimum size.
nla_get_labels() does the remaining validation.

Fixes: e3e4712ec096 ("mpls: ip tunnel support")
Signed-off-by: George Wilkie <gwilkie@vyatta.att-mail.com>
Reviewed-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
net/mpls/mpls_iptunnel.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/net/mpls/mpls_iptunnel.c b/net/mpls/mpls_iptunnel.c
index 6e558a419f60..6c01166f972b 100644
--- a/net/mpls/mpls_iptunnel.c
+++ b/net/mpls/mpls_iptunnel.c
@@ -28,7 +28,7 @@
#include "internal.h"

static const struct nla_policy mpls_iptunnel_policy[MPLS_IPTUNNEL_MAX + 1] = {
- [MPLS_IPTUNNEL_DST] = { .type = NLA_U32 },
+ [MPLS_IPTUNNEL_DST] = { .len = sizeof(u32) },
[MPLS_IPTUNNEL_TTL] = { .type = NLA_U8 },
};

--
2.20.1