diff options
Diffstat (limited to 'drivers/net/tun.c')
| -rw-r--r-- | drivers/net/tun.c | 16 |
1 files changed, 11 insertions, 5 deletions
diff --git a/drivers/net/tun.c b/drivers/net/tun.c index 6032ec80956c..cceed5a2009b 100644 --- a/drivers/net/tun.c +++ b/drivers/net/tun.c @@ -597,7 +597,8 @@ static void tun_detach_all(struct net_device *dev) module_put(THIS_MODULE); } -static int tun_attach(struct tun_struct *tun, struct file *file, bool skip_filter) +static int tun_attach(struct tun_struct *tun, struct file *file, + bool skip_filter, bool publish_tun) { struct tun_file *tfile = file->private_data; int err; @@ -630,7 +631,8 @@ static int tun_attach(struct tun_struct *tun, struct file *file, bool skip_filte } tfile->queue_index = tun->numqueues; tfile->socket.sk->sk_shutdown &= ~RCV_SHUTDOWN; - rcu_assign_pointer(tfile->tun, tun); + if (publish_tun) + rcu_assign_pointer(tfile->tun, tun); rcu_assign_pointer(tun->tfiles[tun->numqueues], tfile); tun->numqueues++; @@ -1638,7 +1640,7 @@ static int tun_set_iff(struct net *net, struct file *file, struct ifreq *ifr) if (err < 0) return err; - err = tun_attach(tun, file, ifr->ifr_flags & IFF_NOFILTER); + err = tun_attach(tun, file, ifr->ifr_flags & IFF_NOFILTER, true); if (err < 0) return err; @@ -1719,13 +1721,17 @@ static int tun_set_iff(struct net *net, struct file *file, struct ifreq *ifr) NETIF_F_HW_VLAN_STAG_TX); INIT_LIST_HEAD(&tun->disabled); - err = tun_attach(tun, file, false); + err = tun_attach(tun, file, false, false); if (err < 0) goto err_free_flow; err = register_netdevice(tun->dev); if (err < 0) goto err_detach; + /* free_netdev() won't check refcnt, to aovid race + * with dev_put() we need publish tun after registration. + */ + rcu_assign_pointer(tfile->tun, tun); } netif_carrier_on(tun->dev); @@ -1864,7 +1870,7 @@ static int tun_set_queue(struct file *file, struct ifreq *ifr) ret = security_tun_dev_attach_queue(tun->security); if (ret < 0) goto unlock; - ret = tun_attach(tun, file, false); + ret = tun_attach(tun, file, false, true); } else if (ifr->ifr_flags & IFF_DETACH_QUEUE) { tun = rtnl_dereference(tfile->tun); if (!tun || !(tun->flags & IFF_MULTI_QUEUE) || tfile->detached) |