[ Upstream commit a53b42c118 ]
We came across infinite loop in ipvs when using ipvs in docker
env.
When ipvs receives new packets and cannot find an ipvs connection,
it will create a new connection, then if the dest is unavailable
(i.e. IP_VS_DEST_F_AVAILABLE), the packet will be dropped sliently.
But if the dropped packet is the first packet of this connection,
the connection control timer never has a chance to start and the
ipvs connection cannot be released. This will lead to memory leak, or
infinite loop in cleanup_net() when net namespace is released like
this:
ip_vs_conn_net_cleanup at ffffffffa0a9f31a [ip_vs]
__ip_vs_cleanup at ffffffffa0a9f60a [ip_vs]
ops_exit_list at ffffffff81567a49
cleanup_net at ffffffff81568b40
process_one_work at ffffffff810a851b
worker_thread at ffffffff810a9356
kthread at ffffffff810b0b6f
ret_from_fork at ffffffff81697a18
race condition:
CPU1 CPU2
ip_vs_in()
ip_vs_conn_new()
ip_vs_del_dest()
__ip_vs_unlink_dest()
~IP_VS_DEST_F_AVAILABLE
cp->dest && !IP_VS_DEST_F_AVAILABLE
__ip_vs_conn_put
...
cleanup_net ---> infinite looping
Fix this by checking whether the timer already started.
Signed-off-by: Tan Hu <tan.hu@zte.com.cn>
Reviewed-by: Jiang Biao <jiang.biao2@zte.com.cn>
Acked-by: Julian Anastasov <ja@ssi.bg>
Acked-by: Simon Horman <horms@verge.net.au>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
ccf1ae823e