RDMA/cma: fix null-ptr-deref Read in cma_cleanup

In cma_init, if cma_configfs_init fails, need to free the
previously memory and return fail, otherwise will trigger
null-ptr-deref Read in cma_cleanup.

cma_cleanup
  cma_configfs_exit
    configfs_unregister_subsystem

Fixes: b168a25da509 ("IB/cma: Add configfs for rdma_cm")
Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: zhengbin <zhengbin13@huawei.com>
Reviewed-by: Parav Pandit <parav@mellanox.com>
Link: https://lore.kernel.org/r/1566188859-103051-1-git-send-email-zhengbin13@huawei.com
Signed-off-by: Doug Ledford <dledford@redhat.com>

diff --git a/drivers/infiniband/core/cma.c b/drivers/infiniband/core/cma.c
index 19f1730a4f2442a175536f290ae40941d3bf954c..a68d0ccf67a431f915822b1f943800c8c3655b8c 100644 (file)
--- a/drivers/infiniband/core/cma.c
+++ b/drivers/infiniband/core/cma.c
@@ -4724,10 +4724,14 @@ static int __init cma_init(void)
        if (ret)
                goto err;
 
-       cma_configfs_init();
+       ret = cma_configfs_init();
+       if (ret)
+               goto err_ib;
 
        return 0;
 
+err_ib:
+       ib_unregister_client(&cma_client);
 err:
        unregister_netdevice_notifier(&cma_nb);
        ib_sa_unregister_client(&sa_client);