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Wei Yongjun authored
commit 751eb6b6 upstream. In general, when DAD detected IPv6 duplicate address, ifp->state will be set to INET6_IFADDR_STATE_ERRDAD and DAD is stopped by a delayed work, the call tree should be like this: ndisc_recv_ns -> addrconf_dad_failure <- missing ifp put -> addrconf_mod_dad_work -> schedule addrconf_dad_work() -> addrconf_dad_stop() <- missing ifp hold before call it addrconf_dad_failure() called with ifp refcont holding but not put. addrconf_dad_work() call addrconf_dad_stop() without extra holding refcount. This will not cause any issue normally. But the race between addrconf_dad_failure() and addrconf_dad_work() may cause ifp refcount leak and netdevice can not be unregister, dmesg show the following messages: IPv6: eth0: IPv6 duplicate address fe80::XX:XXXX:XXXX:XX detected! ... unregister_netdevice: waiting for eth0 to become free. Usage count = 1 Cc: stable@vger.kernel.org Fixes: c15b1cca ("ipv6: move DAD and addrconf_verify processing to workqueue") Signed-off-by:
Wei Yongjun <weiyongjun1@huawei.com> Signed-off-by:
David S. Miller <davem@davemloft.net> Cc: <stable@vger.kernel.org> # 3.10.y Signed-off-by:
Mike Manning <mmanning@brocade.com> Signed-off-by:
Willy Tarreau <w@1wt.eu>
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