From b4c2951a4833e66f1bbfe65ddcd4fdcdfafe5e8f Mon Sep 17 00:00:00 2001
From: Oliver Hartkopp <socketcan@hartkopp.net>
Date: Sat, 2 Dec 2017 18:48:52 +0100
Subject: [PATCH] can: vxcan: improve handling of missing peer name attribute
Git-commit: b4c2951a4833e66f1bbfe65ddcd4fdcdfafe5e8f
Patch-mainline: v4.15-rc8
References: bsc#1051510

Picking up the patch from Serhey Popovych (commit 191cdb3822e5df6b3c8,
"veth: Be more robust on network device creation when no attributes").

When the peer name attribute is not provided the former implementation tries
to register the given device name twice ... which leads to -EEXIST.
If only one device name is given apply an automatic generated and valid name
for the peer.

Cc: Serhey Popovych <serhe.popovych@gmail.com>
Signed-off-by: Oliver Hartkopp <socketcan@hartkopp.net>
Cc: linux-stable <stable@vger.kernel.org>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
Acked-by: Takashi Iwai <tiwai@suse.de>

---
 drivers/net/can/vxcan.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/drivers/net/can/vxcan.c
+++ b/drivers/net/can/vxcan.c
@@ -194,7 +194,7 @@ static int vxcan_newlink(struct net *net
 		tbp = peer_tb;
 	}
 
-	if (tbp[IFLA_IFNAME]) {
+	if (ifmp && tbp[IFLA_IFNAME]) {
 		nla_strlcpy(ifname, tbp[IFLA_IFNAME], IFNAMSIZ);
 		name_assign_type = NET_NAME_USER;
 	} else {