[rds-devel] [PATCH 1/1] net: rds: fix memory leak when unload rds_rdma

[David Miller]

From: Zhu Yanjun <yanjun.zhu at oracle.com>
Date: Mon,  3 Jun 2019 08:48:19 -0400

> When KASAN is enabled, after several rds connections are
> created, then "rmmod rds_rdma" is run. The following will
> appear.
 ...
> This is rds connection memory leak. The root cause is:
> When "rmmod rds_rdma" is run, rds_ib_remove_one will call
> rds_ib_dev_shutdown to drop the rds connections.
> rds_ib_dev_shutdown will call rds_conn_drop to drop rds
> connections as below.
> "
> rds_conn_path_drop(&conn->c_path[0], false);
> "
> In the above, destroy is set to false.
 ...
> In the above function, destroy is set to false. rds_destroy_pending
> is called. This does not move rds connections to ib_nodev_conns.
> So destroy is set to true to move rds connections to ib_nodev_conns.
> In rds_ib_unregister_client, flush_workqueue is called to make rds_wq
> finsh shutdown rds connections. The function rds_ib_destroy_nodev_conns
> is called to shutdown rds connections finally.
> Then rds_ib_recv_exit is called to destroy slab.
 ...
> Suggested-by: Håkon Bugge <haakon.bugge at oracle.com>
> Signed-off-by: Zhu Yanjun <yanjun.zhu at oracle.com>

Applied.