4.4-stable review patch. If anyone has any objections, please let me know.
------------------ From: Mark Bloch <[email protected]> [ 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 <[email protected]> Tested-by: Roi Dayan <[email protected]> Signed-off-by: Mark Bloch <[email protected]> Acked-by: Roopa Prabhu <[email protected]> Signed-off-by: David S. Miller <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]> --- 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);
