From: Petr Machata <petrm@mellanox.com>
Date: Mon, 16 Mar 2020 19:53:00 +0200
Subject: net: ip_gre: Accept IFLA_INFO_DATA-less configuration
Git-commit: 32ca98feab8c9076c89c0697c5a85e46fece809d
Patch-mainline: 5.6
References: networking-stable-20_03_28
The fix referenced below causes a crash when an ERSPAN tunnel is created
without passing IFLA_INFO_DATA. Fix by validating passed-in data in the
same way as ipgre does.
Fixes: e1f8f78ffe98 ("net: ip_gre: Separate ERSPAN newlink / changelink callbacks")
Reported-by: syzbot+1b4ebf4dae4e510dd219@syzkaller.appspotmail.com
Signed-off-by: Petr Machata <petrm@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
---
net/ipv4/ip_gre.c | 2 ++
1 file changed, 2 insertions(+)
--- a/net/ipv4/ip_gre.c
+++ b/net/ipv4/ip_gre.c
@@ -1168,6 +1168,8 @@ static int erspan_netlink_parms(struct n
err = ipgre_netlink_parms(dev, data, tb, parms, fwmark);
if (err)
return err;
+ if (!data)
+ return 0;
if (data[IFLA_GRE_ERSPAN_VER]) {
t->erspan_ver = nla_get_u8(data[IFLA_GRE_ERSPAN_VER]);