From: Nicolas Dichtel <[email protected]> Date: Wed, 5 Jul 2017 17:57:25 +0200
> From: Hongjun Li <[email protected]> > > When the netdev event NETDEV_CHANGEMTU is triggered, the inet[6]dev may be > created even if the corresponding device is down. This may lead to a leak > in the procfs when the device is unregistered, and finally trigger a > backtrace: ... > When a device changes from one netns to another, it's first unregistered, > then the netns reference is updated and the dev is registered in the new > netns. Thus, when a slave moves to another netns, it is first > unregistered. This triggers a NETDEV_UNREGISTER event which is caught by > the bonding driver. The driver calls bond_release(), which calls > dev_set_mtu() and thus triggers NETDEV_CHANGEMTU (the device is still in > the old netns). > > Signed-off-by: Hongjun Li <[email protected]> > Signed-off-by: Nicolas Dichtel <[email protected]> I'm still not convinced about this. We have lots of code which iterates ipv6 idevs, and then has a check for IFF_UP. So having an idev attached to a down interface is not a bug nor illegal. In fact, addrconf_cleanup() walks all of the init_net idevs and calls addrconf_ifdown() with how=1 regardless of IFF_UP or not. This entire area is quite a mess. Can you show exactly why the procfs state isn't cleaned up for these devices moving between namespaces? Maybe that is the real bug and a better place to fix this. Thanks.
