Patch "IB/mlx5: avoid destroying a NULL mr in reg_user_mr error flow" has been added to the 4.2-stable tree

[<gregkh@linuxfoundation.org>]

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

    IB/mlx5: avoid destroying a NULL mr in reg_user_mr error flow

to the 4.2-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-mlx5-avoid-destroying-a-null-mr-in-reg_user_mr-error-flow.patch
and it can be found in the queue-4.2 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@vger.kernel.org> know about it.


>From 11d748045c6dadb279d1acdb6d2ea8f3f2ede85b Mon Sep 17 00:00:00 2001
From: Haggai Eran <haggaie@mellanox.com>
Date: Tue, 1 Sep 2015 09:56:56 +0300
Subject: IB/mlx5: avoid destroying a NULL mr in reg_user_mr error flow

From: Haggai Eran <haggaie@mellanox.com>

commit 11d748045c6dadb279d1acdb6d2ea8f3f2ede85b upstream.

The mlx5_ib_reg_user_mr() function will attempt to call clean_mr() in
its error flow even though there is never a case where the error flow
occurs with a valid MR pointer to destroy.

Remove the clean_mr() call and the incorrect comment above it.

Fixes: b4cfe447d47b ("IB/mlx5: Implement on demand paging by adding
support for MMU notifiers")
Cc: Eli Cohen <eli@mellanox.com>
Signed-off-by: Haggai Eran <haggaie@mellanox.com>
Reviewed-by: Sagi Grimberg <sagig@mellanox.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 drivers/infiniband/hw/mlx5/mr.c |   12 ------------
 1 file changed, 12 deletions(-)

--- a/drivers/infiniband/hw/mlx5/mr.c
+++ b/drivers/infiniband/hw/mlx5/mr.c
@@ -1118,19 +1118,7 @@ struct ib_mr *mlx5_ib_reg_user_mr(struct
 	return &mr->ibmr;
 
 error:
-	/*
-	 * Destroy the umem *before* destroying the MR, to ensure we
-	 * will not have any in-flight notifiers when destroying the
-	 * MR.
-	 *
-	 * As the MR is completely invalid to begin with, and this
-	 * error path is only taken if we can't push the mr entry into
-	 * the pagefault tree, this is safe.
-	 */
-
 	ib_umem_release(umem);
-	/* Kill the MR, and return an error code. */
-	clean_mr(mr);
 	return ERR_PTR(err);
 }
 


Patches currently in stable-queue which might be from haggaie@mellanox.com are

queue-4.2/ib-mlx5-avoid-destroying-a-null-mr-in-reg_user_mr-error-flow.patch