On 21/04/17 22:50, Nikolay Aleksandrov wrote: > On 21/04/17 22:36, David Miller wrote: >> From: Nikolay Aleksandrov <niko...@cumulusnetworks.com> >> Date: Fri, 21 Apr 2017 21:30:42 +0300 >> >>> On 21/04/17 20:42, Nikolay Aleksandrov wrote: >>>> Andrey Konovalov reported a BUG caused by the ip6mr code which is caused >>>> because we call unregister_netdevice_many for a device that is already >>>> being destroyed. In IPv4's ipmr that has been resolved by two commits >>>> long time ago by introducing the "notify" parameter to the delete >>>> function and avoiding the unregister when called from a notifier, so >>>> let's do the same for ip6mr. >> ... >>> +CC LKML and Linus >> >> Applied, thanks Nikolay and thanks Andrey for the report and testing. >> >> Nikolay, how far does this bug go back? >> > > Good question, AFAICS since ip6mr exists because it was copied from ipmr: > commit 7bc570c8b4f7 > Author: YOSHIFUJI Hideaki <yoshf...@linux-ipv6.org> > Date: Thu Apr 3 09:22:53 2008 +0900 > > [IPV6] MROUTE: Support multicast forwarding. > >
Oops no, my bad. That wouldn't cause it to BUG because it was already removed by mif6_delete earlier. So since it can be destroyed by a netns exiting, currently I don't see any other way which is outside of ip6mr for destroying that device. That should be: commit 8229efdaef1e Author: Benjamin Thery <benjamin.th...@bull.net> Date: Wed Dec 10 16:30:15 2008 -0800 netns: ip6mr: enable namespace support in ipv6 multicast forwarding code Which allowed the notifier to be executed for pimreg devices in other network namespaces.