From: Leon Romanovsky <leonro@mellanox.com>
Date: Sun, 31 Dec 2017 15:33:14 +0200
Subject: IB/mlx4: Fix mlx4_ib_alloc_mr error flow
Patch-mainline: v4.15-rc8
Git-commit: 5a371cf87e145b86efd32007e46146e78c1eff6d
References: bsc#1046302 FATE#322945

ibmr.device is being set only after ib_alloc_mr() is successfully complete.
Therefore, in case imlx4_mr_enable() returns with error, the error flow
unwinder calls to mlx4_free_priv_pages(), which uses ibmr.device.

Such usage causes to NULL dereference oops and to fix it, the IB device
should be set in the mr struct earlier stage (e.g. prior to calling
mlx4_free_priv_pages()).

Fixes: 1b2cd0fc673c ("IB/mlx4: Support the new memory registration API")
Signed-off-by: Nitzan Carmi <nitzanc@mellanox.com>
Signed-off-by: Leon Romanovsky <leonro@mellanox.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
Acked-by: Thomas Bogendoerfer <tbogendoerfer@suse.de>
---
 drivers/infiniband/hw/mlx4/mr.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/drivers/infiniband/hw/mlx4/mr.c
+++ b/drivers/infiniband/hw/mlx4/mr.c
@@ -642,7 +642,6 @@ struct ib_mr *mlx4_ib_alloc_mr(struct ib
 		goto err_free_mr;
 
 	mr->max_pages = max_num_sg;
-
 	err = mlx4_mr_enable(dev->dev, &mr->mmr);
 	if (err)
 		goto err_free_pl;
@@ -653,6 +652,7 @@ struct ib_mr *mlx4_ib_alloc_mr(struct ib
 	return &mr->ibmr;
 
 err_free_pl:
+	mr->ibmr.device = pd->device;
 	mlx4_free_priv_pages(mr);
 err_free_mr:
 	(void) mlx4_mr_free(dev->dev, &mr->mmr);