[PATCH 4.19 009/116] macsec: restrict to ethernet devices

[Greg Kroah-Hartman]

From: Willem de Bruijn <willemb@xxxxxxxxxx>

[ Upstream commit b06d072ccc4b1acd0147b17914b7ad1caa1818bb ]

Only attach macsec to ethernet devices.

Syzbot was able to trigger a KMSAN warning in macsec_handle_frame
by attaching to a phonet device.

Macvlan has a similar check in macvlan_port_create.

v1->v2
  - fix commit message typo

Reported-by: syzbot <syzkaller@xxxxxxxxxxxxxxxx>
Signed-off-by: Willem de Bruijn <willemb@xxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
 drivers/net/macsec.c |    3 +++
 1 file changed, 3 insertions(+)

--- a/drivers/net/macsec.c
+++ b/drivers/net/macsec.c
@@ -20,6 +20,7 @@
 #include <net/genetlink.h>
 #include <net/sock.h>
 #include <net/gro_cells.h>
+#include <linux/if_arp.h>
 
 #include <uapi/linux/if_macsec.h>
 
@@ -3248,6 +3249,8 @@ static int macsec_newlink(struct net *ne
 	real_dev = __dev_get_by_index(net, nla_get_u32(tb[IFLA_LINK]));
 	if (!real_dev)
 		return -ENODEV;
+	if (real_dev->type != ARPHRD_ETHER)
+		return -EINVAL;
 
 	dev->priv_flags |= IFF_MACSEC;