From: Guillaume Nault <g.na...@alphalink.fr> Date: Fri, 14 Aug 2015 10:42:56 +0200
> PPP devices may get automatically unregistered when their network > namespace is getting removed. This happens if the ppp control plane > daemon (e.g. pppd) exits while it is the last user of this namespace. > > This leads to several races: > > * ppp_exit_net() may destroy the per namespace idr (pn->units_idr) > before all file descriptors were released. Successive ppp_release() > calls may then cleanup PPP devices with ppp_shutdown_interface() and > try to use the already destroyed idr. > > * Automatic device unregistration may also happen before the > ppp_release() call for that device gets executed. Once called on > the file owning the device, ppp_release() will then clean it up and > try to unregister it a second time. > > To fix these issues, operations defined in ppp_shutdown_interface() are > moved to the PPP device's ndo_uninit() callback. This allows PPP > devices to be properly cleaned up by unregister_netdev() and friends. > So checking for ppp->owner is now an accurate test to decide if a PPP > device should be unregistered. > > Setting ppp->owner is done in ppp_create_interface(), before device > registration, in order to avoid unprotected modification of this field. > > Finally, ppp_exit_net() now starts by unregistering all remaining PPP > devices to ensure that none will get unregistered after the call to > idr_destroy(). > > Signed-off-by: Guillaume Nault <g.na...@alphalink.fr> > --- > v2: remove unnecessary curly braces in idr_for_each_entry() Applied, thank you. -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
