From: Joerg Roedel <[email protected]> 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: [email protected] #v4.4+ Fixes: 1228236de5f9 ('iommu: Move default domain allocation to iommu_group_get_for_dev()') Signed-off-by: Joerg Roedel <[email protected]> --- drivers/iommu/iommu.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c index bfd4f7c..b9df141 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); -- 1.8.4.5
