diff options
| -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 db16d7a13e00..aab0be40d443 100644 --- a/drivers/net/tun.c +++ b/drivers/net/tun.c @@ -787,7 +787,8 @@ static void tun_detach_all(struct net_device *dev) } static int tun_attach(struct tun_struct *tun, struct file *file, - bool skip_filter, bool napi, bool napi_frags) + bool skip_filter, bool napi, bool napi_frags, + bool publish_tun) { struct tun_file *tfile = file->private_data; struct net_device *dev = tun->dev; @@ -870,7 +871,8 @@ static int tun_attach(struct tun_struct *tun, struct file *file, * initialized tfile; otherwise we risk using half-initialized * object. */ - 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++; tun_set_real_num_queues(tun); @@ -2730,7 +2732,7 @@ static int tun_set_iff(struct net *net, struct file *file, struct ifreq *ifr) err = tun_attach(tun, file, ifr->ifr_flags & IFF_NOFILTER, ifr->ifr_flags & IFF_NAPI, - ifr->ifr_flags & IFF_NAPI_FRAGS); + ifr->ifr_flags & IFF_NAPI_FRAGS, true); if (err < 0) return err; @@ -2829,13 +2831,17 @@ static int tun_set_iff(struct net *net, struct file *file, struct ifreq *ifr) INIT_LIST_HEAD(&tun->disabled); err = tun_attach(tun, file, false, ifr->ifr_flags & IFF_NAPI, - ifr->ifr_flags & IFF_NAPI_FRAGS); + ifr->ifr_flags & IFF_NAPI_FRAGS, 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); @@ -2978,7 +2984,7 @@ static int tun_set_queue(struct file *file, struct ifreq *ifr) if (ret < 0) goto unlock; ret = tun_attach(tun, file, false, tun->flags & IFF_NAPI, - tun->flags & IFF_NAPI_FRAGS); + tun->flags & IFF_NAPI_FRAGS, true); } else if (ifr->ifr_flags & IFF_DETACH_QUEUE) { tun = rtnl_dereference(tfile->tun); if (!tun || !(tun->flags & IFF_MULTI_QUEUE) || tfile->detached) |