Patch "iommu: Don't overwrite domain pointer when there is no default_domain" has been added to the 4.5-stable tree

Patch "iommu: Don't overwrite domain pointer when there is no default_domain" has been added to the 4.5-stable tree

[gregkh]

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

    iommu: Don't overwrite domain pointer when there is no default_domain

to the 4.5-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:
     iommu-don-t-overwrite-domain-pointer-when-there-is-no-default_domain.patch
and it can be found in the queue-4.5 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 eebb8034a5be8c2177cbf07ca2ecd2ff8a058958 Mon Sep 17 00:00:00 2001
From: Joerg Roedel <jroedel@suse.de>
Date: Mon, 4 Apr 2016 15:47:48 +0200
Subject: iommu: Don't overwrite domain pointer when there is no default_domain

From: Joerg Roedel <jroedel@suse.de>

commit eebb8034a5be8c2177cbf07ca2ecd2ff8a058958 upstream.

IOMMU drivers that do not support default domains, but make
use of the the group->domain pointer can get that pointer
overwritten with NULL on device add/remove.

Make sure this can't happen by only overwriting the domain
pointer when it is NULL.

Fixes: 1228236de5f9 ('iommu: Move default domain allocation to iommu_group_get_for_dev()')
Signed-off-by: Joerg Roedel <jroedel@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 drivers/iommu/iommu.c |    3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

--- a/drivers/iommu/iommu.c
+++ b/drivers/iommu/iommu.c
@@ -848,7 +848,8 @@ struct iommu_group *iommu_group_get_for_
 	if (!group->default_domain) {
 		group->default_domain = __iommu_domain_alloc(dev->bus,
 							     IOMMU_DOMAIN_DMA);
-		group->domain = group->default_domain;
+		if (!group->domain)
+			group->domain = group->default_domain;
 	}
 
 	ret = iommu_group_add_device(group, dev);


Patches currently in stable-queue which might be from jroedel@suse.de are

queue-4.5/iommu-don-t-overwrite-domain-pointer-when-there-is-no-default_domain.patch