[PATCH AUTOSEL 5.2 59/76] RDMA/cma: fix null-ptr-deref Read in cma_cleanup

[Sasha Levin]

From: zhengbin <zhengbin13@xxxxxxxxxx>

[ Upstream commit a7bfb93f0211b4a2f1ffeeb259ed6206bac30460 ]

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: 045959db65c6 ("IB/cma: Add configfs for rdma_cm")
Reported-by: Hulk Robot <hulkci@xxxxxxxxxx>
Signed-off-by: zhengbin <zhengbin13@xxxxxxxxxx>
Reviewed-by: Parav Pandit <parav@xxxxxxxxxxxx>
Link: https://lore.kernel.org/r/1566188859-103051-1-git-send-email-zhengbin13@xxxxxxxxxx
Signed-off-by: Doug Ledford <dledford@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
 drivers/infiniband/core/cma.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/drivers/infiniband/core/cma.c b/drivers/infiniband/core/cma.c
index 19f1730a4f244..a68d0ccf67a43 100644
--- 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);
-- 
2.20.1