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authorJoerg Roedel <jroedel@suse.de>2016-04-04 15:47:48 +0200
committerJoerg Roedel <jroedel@suse.de>2016-04-07 14:33:03 +0200
commiteebb8034a5be8c2177cbf07ca2ecd2ff8a058958 (patch)
tree0cdbfb78a24c1e68a679cb9d5006e4afcb0e5735
parent07b48ac4bbe527e68cfc555f2b2b206908437141 (diff)
downloadlinux-eebb8034a5be8c2177cbf07ca2ecd2ff8a058958.tar.gz
iommu: Don't overwrite domain pointer when there is no default_domain
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.

Cc: stable@vger.kernel.org # v4.4+
Fixes: 1228236de5f9 ('iommu: Move default domain allocation to iommu_group_get_for_dev()')
Signed-off-by: Joerg Roedel <jroedel@suse.de>
-rw-r--r--drivers/iommu/iommu.c3
1 files changed, 2 insertions, 1 deletions
diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c
index bfd4f7c3b1d8..b9df1411c894 100644
--- a/drivers/iommu/iommu.c
+++ b/drivers/iommu/iommu.c
@@ -848,7 +848,8 @@ struct iommu_group *iommu_group_get_for_dev(struct device *dev)
 	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);