From a6a9a5da68084d5eac6ef85ad09df7fc9c971de4 Mon Sep 17 00:00:00 2001
From: Miaoqian Lin <linmq006@gmail.com>
Date: Fri, 30 Dec 2022 12:31:00 +0400
Subject: [PATCH] iommu: Fix refcount leak in iommu_device_claim_dma_owner
iommu_group_get() returns the group with the reference incremented.
Move iommu_group_get() after owner check to fix the refcount leak.
Fixes: 89395ccedbc1 ("iommu: Add device-centric DMA ownership interfaces")
Signed-off-by: Miaoqian Lin <linmq006@gmail.com>
Reviewed-by: Lu Baolu <baolu.lu@linux.intel.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Link: https://lore.kernel.org/r/20221230083100.1489569-1-linmq006@gmail.com
[ joro: Remove *group = NULL initialization ]
Signed-off-by: Joerg Roedel <jroedel@suse.de>
---
drivers/iommu/iommu.c | 8 +++++---
1 file changed, 5 insertions(+), 3 deletions(-)
diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c
index de91dd88705bd..5f6a85aea501e 100644
--- a/drivers/iommu/iommu.c
+++ b/drivers/iommu/iommu.c
@@ -3185,14 +3185,16 @@ EXPORT_SYMBOL_GPL(iommu_group_claim_dma_owner);
*/
int iommu_device_claim_dma_owner(struct device *dev, void *owner)
{
- struct iommu_group *group = iommu_group_get(dev);
+ struct iommu_group *group;
int ret = 0;
- if (!group)
- return -ENODEV;
if (WARN_ON(!owner))
return -EINVAL;
+ group = iommu_group_get(dev);
+ if (!group)
+ return -ENODEV;
+
mutex_lock(&group->mutex);
if (group->owner_cnt) {
if (group->owner != owner) {
--
2.30.2