4.9-stable review patch. If anyone has any objections, please let me know.
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From: Mike Manning mmanning@brocade.com
[ Upstream commit 1f372c7bfb23286d2bf4ce0423ab488e86b74bb2 ]
The NS for DAD are sent on admin up as long as a valid qdisc is found. A race condition exists by which these packets will not egress the interface if the operational state of the lower device is not yet up. The solution is to delay DAD until the link is operationally up according to RFC2863. Rather than only doing this, follow the existing code checks by deferring IPv6 device initialization altogether. The fix allows DAD on devices like tunnels that are controlled by userspace control plane. The fix has no impact on regular deployments, but means that there is no IPv6 connectivity until the port has been opened in the case of port-based network access control, which should be desirable.
Signed-off-by: Mike Manning mmanning@brocade.com Signed-off-by: David S. Miller davem@davemloft.net Signed-off-by: Sasha Levin alexander.levin@verizon.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- net/ipv6/addrconf.c | 12 ++++++------ 1 file changed, 6 insertions(+), 6 deletions(-)
--- a/net/ipv6/addrconf.c +++ b/net/ipv6/addrconf.c @@ -286,10 +286,10 @@ static struct ipv6_devconf ipv6_devconf_ .keep_addr_on_down = 0, };
-/* Check if a valid qdisc is available */ -static inline bool addrconf_qdisc_ok(const struct net_device *dev) +/* Check if link is ready: is it up and is a valid qdisc available */ +static inline bool addrconf_link_ready(const struct net_device *dev) { - return !qdisc_tx_is_noop(dev); + return netif_oper_up(dev) && !qdisc_tx_is_noop(dev); }
static void addrconf_del_rs_timer(struct inet6_dev *idev) @@ -434,7 +434,7 @@ static struct inet6_dev *ipv6_add_dev(st
ndev->token = in6addr_any;
- if (netif_running(dev) && addrconf_qdisc_ok(dev)) + if (netif_running(dev) && addrconf_link_ready(dev)) ndev->if_flags |= IF_READY;
ipv6_mc_init_dev(ndev); @@ -3368,7 +3368,7 @@ static int addrconf_notify(struct notifi /* restore routes for permanent addresses */ addrconf_permanent_addr(dev);
- if (!addrconf_qdisc_ok(dev)) { + if (!addrconf_link_ready(dev)) { /* device is not ready yet. */ pr_info("ADDRCONF(NETDEV_UP): %s: link is not ready\n", dev->name); @@ -3383,7 +3383,7 @@ static int addrconf_notify(struct notifi run_pending = 1; } } else if (event == NETDEV_CHANGE) { - if (!addrconf_qdisc_ok(dev)) { + if (!addrconf_link_ready(dev)) { /* device is still not ready. */ break; }