[PATCH 3.10 219/319] ipv6: don't call fib6_run_gc() until routing is ready

Willy Tarreau
2017-02-05T19:57:21Z

From: Michal KubeÄek <mkubecek@suse.cz>

commit 2c861cc65ef4604011a0082e4dcdba2819aa191a upstream.

When loading the ipv6 module, ndisc_init() is called before
ip6_route_init(). As the former registers a handler calling
fib6_run_gc(), this opens a window to run the garbage collector
before necessary data structures are initialized. If a network
device is initialized in this window, adding MAC address to it
triggers a NETDEV_CHANGEADDR event, leading to a crash in
fib6_clean_all().

Take the event handler registration out of ndisc_init() into a
separate function ndisc_late_init() and move it after
ip6_route_init().

Signed-off-by: Michal Kubecek <mkubecek@suse.cz>
Signed-off-by: David S. Miller <davem@davemloft.net>
Cc: <stable@vger.kernel.org>
Signed-off-by: Mike Manning <mmanning@brocade.com>
Signed-off-by: Willy Tarreau <w@1wt.eu>
---
include/net/ndisc.h | 2 ++
net/ipv6/af_inet6.c | 6 ++++++
net/ipv6/ndisc.c | 18 +++++++++++-------
3 files changed, 19 insertions(+), 7 deletions(-)

diff --git a/include/net/ndisc.h b/include/net/ndisc.h
index 5043f8b..4b12d99 100644
--- a/include/net/ndisc.h
+++ b/include/net/ndisc.h
@@ -190,7 +190,9 @@ static inline struct neighbour *__ipv6_neigh_lookup(struct net_device *dev, cons
}

extern int ndisc_init(void);
+extern int ndisc_late_init(void);

+extern void ndisc_late_cleanup(void);
extern void ndisc_cleanup(void);

extern int ndisc_rcv(struct sk_buff *skb);
diff --git a/net/ipv6/af_inet6.c b/net/ipv6/af_inet6.c
index a944f13..9443af7 100644
--- a/net/ipv6/af_inet6.c
+++ b/net/ipv6/af_inet6.c
@@ -900,6 +900,9 @@ static int __init inet6_init(void)
err = ip6_route_init();
if (err)
goto ip6_route_fail;
+ err = ndisc_late_init();
+ if (err)
+ goto ndisc_late_fail;
err = ip6_flowlabel_init();
if (err)
goto ip6_flowlabel_fail;
@@ -960,6 +963,8 @@ ipv6_exthdrs_fail:
addrconf_fail:
ip6_flowlabel_cleanup();
ip6_flowlabel_fail:
+ ndisc_late_cleanup();
+ndisc_late_fail:
ip6_route_cleanup();
ip6_route_fail:
#ifdef CONFIG_PROC_FS
@@ -1020,6 +1025,7 @@ static void __exit inet6_exit(void)
ipv6_exthdrs_exit();
addrconf_cleanup();
ip6_flowlabel_cleanup();
+ ndisc_late_cleanup();
ip6_route_cleanup();
#ifdef CONFIG_PROC_FS

diff --git a/net/ipv6/ndisc.c b/net/ipv6/ndisc.c
index deedf7d..de10ccf 100644
--- a/net/ipv6/ndisc.c
+++ b/net/ipv6/ndisc.c
@@ -1716,24 +1716,28 @@ int __init ndisc_init(void)
if (err)
goto out_unregister_pernet;
#endif
- err = register_netdevice_notifier(&ndisc_netdev_notifier);
- if (err)
- goto out_unregister_sysctl;
out:
return err;

-out_unregister_sysctl:
#ifdef CONFIG_SYSCTL
- neigh_sysctl_unregister(&nd_tbl.parms);
out_unregister_pernet:
-#endif
unregister_pernet_subsys(&ndisc_net_ops);
goto out;
+#endif
}

-void ndisc_cleanup(void)
+int __init ndisc_late_init(void)
+{
+ return register_netdevice_notifier(&ndisc_netdev_notifier);
+}
+
+void ndisc_late_cleanup(void)
{
unregister_netdevice_notifier(&ndisc_netdev_notifier);
+}
+
+void ndisc_cleanup(void)
+{
#ifdef CONFIG_SYSCTL
neigh_sysctl_unregister(&nd_tbl.parms);
#endif
--
2.8.0.rc2.1.gbe9624a