On 1/30/18 1:08 PM, Daniel Borkmann wrote: > On 01/30/2018 07:32 PM, Cong Wang wrote: >> On Tue, Jan 30, 2018 at 4:09 AM, Dmitry Vyukov <dvyu...@google.com> wrote: >>> Hello, >>> >>> The following program creates a hang in unregister_netdevice. >>> cleanup_net work hangs there forever periodically printing >>> "unregister_netdevice: waiting for lo to become free. Usage count = 3" >>> and creation of any new network namespaces hangs forever. >> >> Interestingly, this is not reproducible on net-next. > > The most recent change on netns refcnt was 4ee806d51176 ("net: tcp: close > sock if net namespace is exiting") in net/net-next from 5 days ago, maybe > fixed due to that? >
This appears to be the commit introducing the refcnt leak: $ git bisect bad dbc2b5e9a09e9a6664679a667ff81cff6e5f2641 is the first bad commit commit dbc2b5e9a09e9a6664679a667ff81cff6e5f2641 Author: Xin Long <lucien....@gmail.com> Date: Fri May 12 14:39:52 2017 +0800 sctp: fix src address selection if using secondary addresses for ipv6 v4.14 is bad. Running bisect in the background while doing other things....