4.4-stable review patch. If anyone has any objections, please let me know.
------------------
From: Mark Bloch <markb@xxxxxxxxxxxx>
[ Upstream commit a53cb29b0af346af44e4abf13d7e59f807fba690 ]
Adding a vxlan interface to a socket isn't symmetrical, while adding
is done in vxlan_open() the deletion is done in vxlan_dellink().
This can cause a use-after-free error when we close the vxlan
interface before deleting it.
We add vxlan_vs_del_dev() to match vxlan_vs_add_dev() and call
it from vxlan_stop() to match the call from vxlan_open().
Fixes: 56ef9c909b40 ("vxlan: Move socket initialization to within rtnl scope")
Acked-by: Jiri Benc <jbenc@xxxxxxxxxx>
Tested-by: Roi Dayan <roid@xxxxxxxxxxxx>
Signed-off-by: Mark Bloch <markb@xxxxxxxxxxxx>
Acked-by: Roopa Prabhu <roopa@xxxxxxxxxxxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/net/vxlan.c | 19 +++++++++++++------
1 file changed, 13 insertions(+), 6 deletions(-)
--- a/drivers/net/vxlan.c
+++ b/drivers/net/vxlan.c
@@ -77,6 +77,8 @@ static const u8 all_zeros_mac[ETH_ALEN];
static int vxlan_sock_add(struct vxlan_dev *vxlan);
+static void vxlan_vs_del_dev(struct vxlan_dev *vxlan);
+
/* per-network namespace private data for this module */
struct vxlan_net {
struct list_head vxlan_list;
@@ -1052,6 +1054,8 @@ static void __vxlan_sock_release(struct
static void vxlan_sock_release(struct vxlan_dev *vxlan)
{
+ vxlan_vs_del_dev(vxlan);
+
__vxlan_sock_release(vxlan->vn4_sock);
#if IS_ENABLED(CONFIG_IPV6)
__vxlan_sock_release(vxlan->vn6_sock);
@@ -2255,6 +2259,15 @@ static void vxlan_cleanup(unsigned long
mod_timer(&vxlan->age_timer, next_timer);
}
+static void vxlan_vs_del_dev(struct vxlan_dev *vxlan)
+{
+ struct vxlan_net *vn = net_generic(vxlan->net, vxlan_net_id);
+
+ spin_lock(&vn->sock_lock);
+ hlist_del_init_rcu(&vxlan->hlist);
+ spin_unlock(&vn->sock_lock);
+}
+
static void vxlan_vs_add_dev(struct vxlan_sock *vs, struct vxlan_dev *vxlan)
{
struct vxlan_net *vn = net_generic(vxlan->net, vxlan_net_id);
@@ -3028,12 +3041,6 @@ static int vxlan_newlink(struct net *src
static void vxlan_dellink(struct net_device *dev, struct list_head *head)
{
struct vxlan_dev *vxlan = netdev_priv(dev);
- struct vxlan_net *vn = net_generic(vxlan->net, vxlan_net_id);
-
- spin_lock(&vn->sock_lock);
- if (!hlist_unhashed(&vxlan->hlist))
- hlist_del_rcu(&vxlan->hlist);
- spin_unlock(&vn->sock_lock);
gro_cells_destroy(&vxlan->gro_cells);
list_del(&vxlan->next);