On Sun, 2015-12-13 at 20:20 +0000, Ben Hutchings wrote: > On Sun, 2015-12-13 at 18:54 +0000, Luis Henriques wrote: > > On Sat, Dec 12, 2015 at 04:18:26AM +0000, Ben Hutchings wrote: > > > On Wed, 2015-12-09 at 09:36 +0000, Luis Henriques wrote: > > > > 3.16.7-ckt21 -stable review patch. If anyone has any objections, > > > > please let me know. > > > > > > > > ------------------ > > > > > > > > From: Eric Dumazet <edumazet@xxxxxxxxxx> > > > > > > > > commit 4ece9009774596ee3df0acba65a324b7ea79387c upstream. > > > > > > > > sit0 device allocates its percpu storage twice : > > > > - One time in ipip6_tunnel_init() > > > > - One time in ipip6_fb_tunnel_init() > > > > > > > > Thus we leak 48 bytes per possible cpu per network namespace > > > > dismantle. > > > > > > > > ipip6_fb_tunnel_init() can be much simpler and does not > > > > return an error, and should be called after register_netdev() > > > [...] > > > > > > Doesn't this introduce a race condition when sit is a module? There > > > seems to be nothing to prevent access to the partially initialised > > > device after calling register_netdev(), if sit_init_net() is called > > > during module loading rather than during namespace creation. > > > > > > > This seems to be an upstream issue, not specific to the 3.16.y-ckt > > stable kernel. If that is the case, I guess I'll just keep this patch > > and later apply the fix. Or do you think this race is really likely > > to be a worst problem than then issue the patch is trying to fix? > > It seems worse than the problem being fixed. 1) Sorry Ben, I do not understand the problem you mention. What is a partially initialized device exactly ? 2) I have no idea why this patch is even backported to 3.16, since it is fixing a problem added in 3.18 : # git describe --contains ebe084aafb7e v3.18-rc5~22^2~42^2~1 If your 3.16 kernel survives this loop without consuming memory like crazy, then the backport is not needed. modprobe sit while : do ip netns add ns1 ip netns delete ns1 done -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html