[PATCH V2 2/3] tuntap: forbid calling TUNSETIFF when detached
From: Jason Wang <hidden>
Date: 2013-01-12 03:08:05
Also in:
lkml
Subsystem:
networking drivers, the rest, tun/tap driver · Maintainers:
Andrew Lunn, "David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Linus Torvalds, Willem de Bruijn, Jason Wang
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 <mst@redhat.com> Cc: Stefan Hajnoczi <stefanha@redhat.com> Signed-off-by: Jason Wang <redacted> --- drivers/net/tun.c | 5 +++-- 1 files changed, 3 insertions(+), 2 deletions(-)
diff --git a/drivers/net/tun.c b/drivers/net/tun.c
index aa963c4..a36b56f 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)
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1.7.1