[Bug 210724] panic on vnet destroy on recent FreeBSD 11-ALPHA5: vnet or rw_wlock_hard related

[Bjoern A. Zeeb]

On Thu, 30 Jun 2016, bugzilla-noreply at freebsd.org wrote:

> https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=210724
>
>            Bug ID: 210724
>           Summary: panic on vnet destroy on recent FreeBSD 11-ALPHA5:
>                    vnet or rw_wlock_hard related
>           Product: Base System
>           Version: 11.0-CURRENT
>          Hardware: Any
>                OS: Any
>            Status: New
>          Severity: Affects Only Me
>          Priority: ---
>         Component: kern
>          Assignee: freebsd-bugs at FreeBSD.org
>          Reporter: olevole at olevole.ru
>
> FreeBSD 11.0-ALPHA5 r302206
>
> When destroy vnet-based interfaces, FreeBSD panic with Fatal trap 12:

Hi,

I cannot login to bugzilla currently from here, but could you try:

Index: sys/netpfil/ipfw/ip_fw_nat.c
===================================================================
--- sys/netpfil/ipfw/ip_fw_nat.c        (revision 302298)
+++ sys/netpfil/ipfw/ip_fw_nat.c        (working copy)
@@ -104,6 +104,10 @@ ifaddr_change(void *arg __unused, struct ifnet *if

         KASSERT(curvnet == ifp->if_vnet,
             ("curvnet(%p) differs from iface vnet(%p)", curvnet, ifp->if_vnet));
+
+       if (V_ipfw_vnet_ready == 0 || V_ipfw_nat_ready == 0)
+               return;
+
         chain = &V_layer3_chain;
         IPFW_UH_WLOCK(chain);
         /* Check every nat entry... */
@@ -1145,12 +1149,12 @@ vnet_ipfw_nat_uninit(const void *arg __unused)

         chain = &V_layer3_chain;
         IPFW_WLOCK(chain);
+       V_ipfw_nat_ready = 0;
         LIST_FOREACH_SAFE(ptr, &chain->nat, _next, ptr_temp) {
                 LIST_REMOVE(ptr, _next);
                 free_nat_instance(ptr);
         }
         flush_nat_ptrs(chain, -1 /* flush all */);
-       V_ipfw_nat_ready = 0;
         IPFW_WUNLOCK(chain);
         return (0);
  }

-- 
Bjoern A. Zeeb                                                     r15:7