On Fri, Apr 14, 2017 at 09:13:40AM +0800, gfree.wind@xxxxxxxxxxx wrote: > From: Gao Feng <fgao@xxxxxxxxxx> > > The function ctnl_untimeout is used to untimeout every conntrack > which is using the timeout. But it is necessary to add one barrier > synchronize_rcu because of racing. Maybe one conntrack has already > owned this timeout, but it is not inserted into unconfirmed list or > the hash list, when ctnl_untimeout untimeout the conntracks > > Let me describe it with a call path > CPU1 CPU2 > alloc new conn > add timeout ext > ctnl_timeout_try_del > untimeout all conns in list > kfree_rcu. > conn is confirmed. Then this confirmed conn gets a timeout_ext->timeout == NULL since ctnl_untimeout() is called first. -- To unsubscribe from this list: send the line "unsubscribe netfilter-devel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
