From mboxrd@z Thu Jan 1 00:00:00 1970 From: Konstantin Khlebnikov Subject: Re: 4.4.103 linux kernel regression Date: Sun, 24 Dec 2017 12:25:22 +0300 Message-ID: References: <20171223135249.GA16617@kroah.com> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit Cc: Greg KH , netdev@vger.kernel.org, stable@vger.kernel.org, xiyou.wangcong@gmail.com, dsahern@gmail.com, jeffy.chen@rock-chips.com, davem@davemloft.net To: Mathias Tillman Return-path: In-Reply-To: Content-Language: ru-RU Sender: stable-owner@vger.kernel.org List-Id: netdev.vger.kernel.org On 23.12.2017 21:10, Mathias Tillman wrote: > Thank you, I will test that patch and see if I can find anything interesting in the log. Will have to be some time later next week due to > the holidays, but I will get back to you with the results. Ok, I'll be waiting. Probably you could share your kernel config and lsmod output? > > What commit are you referring to exactly? I can test it to see if it's fixed. Commit that was added into v4.4.103 - 76da0704507bbc51875013f6557877ab308cfd0a upstream. > > Also, I should mention that it's not just vsftpd it causes problems with - some other people have reported problems with starting and > stopping lxc containers. I don't use those myself so I can't really comment on that, but it does seem to have been fixed by reverting the > commit I mentioned. Yes. This is common problem for all network namespaces. Bug somewhere else and requires particular configuration. > > Greg: Can't say if the problem exists on master or not - I'm really only able to reproduce it on the Turris Omnia router as I said in the > bug report. It's based on openwrt and requires some device-specific patches to function properly, so I'm not sure it would work on the > latest - but I can give it a try. > > Regards > Mathias > > > On Sat, 23 Dec 2017, 17:36 Konstantin Khlebnikov, > wrote: > > On 23.12.2017 16:52, Greg KH wrote: > > adding stable@ and netdev@ > > > > On Sat, Dec 23, 2017 at 10:49:27AM +0000, Mathias Tillman wrote: > >> Hi, I wanted to make you aware of a recent regression to the Linux kernel > >> introduced with commit 2417da3f4d6bc4fc6c77f613f0e2264090892aa5: > >> > https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux-stable.git/commit/net/ipv6?h=linux-4.4.y&id=2417da3f4d6bc4fc6c77f613f0e2264090892aa5 > > > > Is this issue also present in Linus's tree? > > > >> I have reported it here: > >> https://bugzilla.kernel.org/show_bug.cgi?id=198189 > > > > Bugzilla doesn't work for networking bugs, nor stable stuff, just for a > > few subsystems, sorry. > > > >> Basically, that commit causes an endless loop if, for some reason, not all > >> devices are unregistered in the rollback_registered_many function in > >> net/dev.c > >> > >> Decided to contact you directly since I have yet to receive any reply on > >> the bug report, and I wasn't entirely sure what the procedure was. Please > >> do let me know if I have to change anything in the report. > > > > I can revert it, but it would be good to verify if this is an issue in > > the latest releases or not first. > > Most likely bug fixed by that commit hid refcount leak for loopback device. > > Mathias, please try debug patch from attachment. > It logs all refcount changes for loopback in non-host net namespace. > Hopefully log would will be tiny and show what is missing. > > Looks like vsftpd creates and destroys empty net-ns, like "unshare -n true" >