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| author | WANG Cong <xiyou.wangcong@gmail.com> | 2017-06-20 11:42:27 -0700 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2017-06-22 11:06:06 -0400 |
| commit | 76da0704507bbc51875013f6557877ab308cfd0a (patch) | |
| tree | bcfd0d5bb6df4ad832b37676ca2c8ec229473de5 /net/ipv6/route.c | |
| parent | b866203d872d5deeafcecd25ea429d6748b5bd56 (diff) | |
| download | lwn-76da0704507bbc51875013f6557877ab308cfd0a.tar.gz lwn-76da0704507bbc51875013f6557877ab308cfd0a.zip | |
ipv6: only call ip6_route_dev_notify() once for NETDEV_UNREGISTER
In commit 242d3a49a2a1 ("ipv6: reorder ip6_route_dev_notifier after ipv6_dev_notf")
I assumed NETDEV_REGISTER and NETDEV_UNREGISTER are paired,
unfortunately, as reported by jeffy, netdev_wait_allrefs()
could rebroadcast NETDEV_UNREGISTER event until all refs are
gone.
We have to add an additional check to avoid this corner case.
For netdev_wait_allrefs() dev->reg_state is NETREG_UNREGISTERED,
for dev_change_net_namespace(), dev->reg_state is
NETREG_REGISTERED. So check for dev->reg_state != NETREG_UNREGISTERED.
Fixes: 242d3a49a2a1 ("ipv6: reorder ip6_route_dev_notifier after ipv6_dev_notf")
Reported-by: jeffy <jeffy.chen@rock-chips.com>
Cc: David Ahern <dsahern@gmail.com>
Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
Acked-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/ipv6/route.c')
| -rw-r--r-- | net/ipv6/route.c | 6 |
1 files changed, 5 insertions, 1 deletions
diff --git a/net/ipv6/route.c b/net/ipv6/route.c index 7cebd954d5bb..322bd62e688b 100644 --- a/net/ipv6/route.c +++ b/net/ipv6/route.c @@ -3722,7 +3722,11 @@ static int ip6_route_dev_notify(struct notifier_block *this, net->ipv6.ip6_blk_hole_entry->dst.dev = dev; net->ipv6.ip6_blk_hole_entry->rt6i_idev = in6_dev_get(dev); #endif - } else if (event == NETDEV_UNREGISTER) { + } else if (event == NETDEV_UNREGISTER && + dev->reg_state != NETREG_UNREGISTERED) { + /* NETDEV_UNREGISTER could be fired for multiple times by + * netdev_wait_allrefs(). Make sure we only call this once. + */ in6_dev_put(net->ipv6.ip6_null_entry->rt6i_idev); #ifdef CONFIG_IPV6_MULTIPLE_TABLES in6_dev_put(net->ipv6.ip6_prohibit_entry->rt6i_idev); |