From: Jason Wang Date: Fri, 11 Jan 2013 16:59:33 +0000 (+0000) Subject: tuntap: forbid calling TUNSETIFF when detached X-Git-Url: https://openfabrics.org/gitweb/?a=commitdiff_plain;h=7c0c3b1a8a175437991ccc898ed66ec5e4a96208;p=~shefty%2Frdma-dev.git tuntap: forbid calling TUNSETIFF when detached Michael points out that even after Stefan's fix the TUNSETIFF is still allowed to create a new tap device. This because we only check tfile->tun but the tfile->detached were introduced. Fix this by failing early in tun_set_iff() if the file is detached. After this fix, there's no need to do the check again in tun_set_iff(), so this patch removes it. Cc: Michael S. Tsirkin Cc: Stefan Hajnoczi Signed-off-by: Jason Wang Signed-off-by: David S. Miller --- diff --git a/drivers/net/tun.c b/drivers/net/tun.c index aa963c44450..a36b56f0940 100644 --- a/drivers/net/tun.c +++ b/drivers/net/tun.c @@ -488,8 +488,6 @@ static int tun_attach(struct tun_struct *tun, struct file *file) err = -EINVAL; if (rtnl_dereference(tfile->tun)) goto out; - if (tfile->detached && tun != tfile->detached) - goto out; err = -EBUSY; if (!(tun->flags & TUN_TAP_MQ) && tun->numqueues == 1) @@ -1543,6 +1541,9 @@ static int tun_set_iff(struct net *net, struct file *file, struct ifreq *ifr) struct net_device *dev; int err; + if (tfile->detached) + return -EINVAL; + dev = __dev_get_by_name(net, ifr->ifr_name); if (dev) { if (ifr->ifr_flags & IFF_TUN_EXCL)