From: Roopa Prabhu <roopa@cumulusnetworks.com>
Date: Sun, 31 May 2020 05:17:20 +0000 (-0700)
Subject: vxlan: fix dereference of nexthop group in nexthop update path
X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=03eaeda7806dcafb221a66939fcec9748619d16a;p=linux.git

vxlan: fix dereference of nexthop group in nexthop update path

fix dereference of nexthop group in fdb nexthop group
update validation path.

Fixes: 1274e1cc4226 ("vxlan: ecmp support for mac fdb entries")
Reported-by: Ido Schimmel <idosch@idosch.org>
Suggested-by: Ido Schimmel <idosch@idosch.org>
Signed-off-by: Roopa Prabhu <roopa@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
---

diff --git a/drivers/net/vxlan.c b/drivers/net/vxlan.c
index d5906b41cdaea..5bb448ae6c9c4 100644
--- a/drivers/net/vxlan.c
+++ b/drivers/net/vxlan.c
@@ -881,13 +881,13 @@ static int vxlan_fdb_nh_update(struct vxlan_dev *vxlan, struct vxlan_fdb *fdb,
 			goto err_inval;
 		}
 
-		if (!nh->is_group || !nh->nh_grp->mpath) {
+		nhg = rtnl_dereference(nh->nh_grp);
+		if (!nh->is_group || !nhg->mpath) {
 			NL_SET_ERR_MSG(extack, "Nexthop is not a multipath group");
 			goto err_inval;
 		}
 
 		/* check nexthop group family */
-		nhg = rtnl_dereference(nh->nh_grp);
 		switch (vxlan->default_dst.remote_ip.sa.sa_family) {
 		case AF_INET:
 			if (!nhg->has_v4) {