Patch "IB/mlx4: Fix mlx4_ib_alloc_mr error flow" has been added to the 4.9-stable tree

This is a note to let you know that I've just added the patch titled

IB/mlx4: Fix mlx4_ib_alloc_mr error flow

to the 4.9-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
ib-mlx4-fix-mlx4_ib_alloc_mr-error-flow.patch
and it can be found in the queue-4.9 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree, please let <[email protected]> know about it.

From: Leon Romanovsky <[email protected]>
Date: Sun, 31 Dec 2017 15:33:14 +0200
Subject: IB/mlx4: Fix mlx4_ib_alloc_mr error flow

From: Leon Romanovsky <[email protected]>

[ Upstream commit 5a371cf87e145b86efd32007e46146e78c1eff6d ]

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()).

---
 drivers/infiniband/hw/mlx4/mr.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

@@ -406,7 +406,6 @@ 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;

@@ -417,6 +416,7 @@ 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);

Patches currently in stable-queue which might be from [email protected] are

queue-4.9/ib-mlx4-fix-mlx4_ib_alloc_mr-error-flow.patch