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authorMark Bloch <markb@mellanox.com>2017-06-02 03:24:08 +0300
committerDavid S. Miller <davem@davemloft.net>2017-06-02 14:29:16 -0400
commita53cb29b0af346af44e4abf13d7e59f807fba690 (patch)
treeebd6ee47e68e774a12c024102cc36b3aee5085ee
parent78b07ac1e4c8acc9daf6b7f7b579300328673640 (diff)
downloadclk-a53cb29b0af346af44e4abf13d7e59f807fba690.tar.gz
vxlan: fix use-after-free on deletion
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@redhat.com> Tested-by: Roi Dayan <roid@mellanox.com> Signed-off-by: Mark Bloch <markb@mellanox.com> Acked-by: Roopa Prabhu <roopa@cumulusnetworks.com> Signed-off-by: David S. Miller <davem@davemloft.net>
-rw-r--r--drivers/net/vxlan.c19
1 files changed, 13 insertions, 6 deletions
diff --git a/drivers/net/vxlan.c b/drivers/net/vxlan.c
index 5c1d69e37870d..a6b5052c1d36b 100644
--- a/drivers/net/vxlan.c
+++ b/drivers/net/vxlan.c
@@ -59,6 +59,8 @@ static const u8 all_zeros_mac[ETH_ALEN + 2];
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;
@@ -1081,6 +1083,8 @@ static void vxlan_sock_release(struct vxlan_dev *vxlan)
rcu_assign_pointer(vxlan->vn4_sock, NULL);
synchronize_net();
+ vxlan_vs_del_dev(vxlan);
+
if (__vxlan_sock_release_prep(sock4)) {
udp_tunnel_sock_release(sock4->sock);
kfree(sock4);
@@ -2356,6 +2360,15 @@ static void vxlan_cleanup(unsigned long arg)
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);
@@ -3300,15 +3313,9 @@ static int vxlan_changelink(struct net_device *dev, struct nlattr *tb[],
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);
vxlan_flush(vxlan, true);
- 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);
unregister_netdevice_queue(dev, head);