Messages in this thread | | | Date | Wed, 11 Sep 2013 12:38:43 +0300 | From | "Michael S. Tsirkin" <> | Subject | Re: [PATCH net] tuntap: correctly handle error in tun_set_iff() |
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On Wed, Sep 11, 2013 at 04:24:05PM +0800, Jason Wang wrote: > Commit c8d68e6be1c3b242f1c598595830890b65cea64a (tuntap: multiqueue support) > only call free_netdev() on err in tun_set_iff(). This causes several issues: > > - memory of tun security were leaked
Not just tun security - sock reference too (didn't detach)
> - use after free since the flow gc timer was not deleted and the tfile were not > detached > > This patch solves the above issues. > > Reported-by: Wannes Rombouts <wannes.rombouts@epitech.eu> > Cc: Michael S. Tsirkin <mst@redhat.com> > Signed-off-by: Jason Wang <jasowang@redhat.com> > --- > The patch were also needed for stable 3.8+. > --- > drivers/net/tun.c | 9 +++++++-- > 1 files changed, 7 insertions(+), 2 deletions(-) > > diff --git a/drivers/net/tun.c b/drivers/net/tun.c > index a639de8..e5fb5d3 100644 > --- a/drivers/net/tun.c > +++ b/drivers/net/tun.c > @@ -1641,11 +1641,11 @@ 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); > if (err < 0) > - goto err_free_dev; > + goto err_free_flow; > > err = register_netdevice(tun->dev); > if (err < 0) > - goto err_free_dev; > + goto err_detach; > > if (device_create_file(&tun->dev->dev, &dev_attr_tun_flags) || > device_create_file(&tun->dev->dev, &dev_attr_owner) || > @@ -1689,6 +1689,11 @@ static int tun_set_iff(struct net *net, struct file *file, struct ifreq *ifr) > strcpy(ifr->ifr_name, tun->dev->name); > return 0; > > +err_detach: > + tun_detach_all(dev); > +err_free_flow: > + tun_flow_uninit(tun); > + security_tun_dev_free_security(tun->security);
This bit looks wrong: if flow_init fails, we need security_tun_dev_free_security, don't we? I think we need: +err_free_sec: security_tun_dev_free_security(tun->security); and goto here on flow_init failures.
> err_free_dev:
Pls shift this one 1 space left for consistency.
> free_netdev(dev); > return err; > -- > 1.7.1
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