iommu: Fix a leak in iommu_insert_resv_region

[ Upstream commit ad0834de ]

In case we expand an existing region, we unlink
this latter and insert the larger one. In
that case we should free the original region after
the insertion. Also we can immediately return.

Fixes: 6c65fb31 ("iommu: iommu_get_group_resv_regions")
Signed-off-by: NEric Auger <eric.auger@redhat.com>
Signed-off-by: NJoerg Roedel <jroedel@suse.de>
Signed-off-by: NSasha Levin <sashal@kernel.org>
Signed-off-by: NYang Yingliang <yangyingliang@huawei.com>

drivers/iommu/iommu.c

@@ -221,18 +221,21 @@ static int iommu_insert_resv_region(struct iommu_resv_region *new,
 			pos = pos->next;
 		} else if ((start >= a) && (end <= b)) {
 			if (new->type == type)
-				goto done;
+				return 0;
 			else
 				pos = pos->next;
 		} else {
 			if (new->type == type) {
 				phys_addr_t new_start = min(a, start);
 				phys_addr_t new_end = max(b, end);
+				int ret;
 
 				list_del(&entry->list);
 				entry->start = new_start;
 				entry->length = new_end - new_start + 1;
-				iommu_insert_resv_region(entry, regions);
+				ret = iommu_insert_resv_region(entry, regions);
+				kfree(entry);
+				return ret;
 			} else {
 				pos = pos->next;
 			}
@@ -245,7 +248,6 @@ static int iommu_insert_resv_region(struct iommu_resv_region *new,
 		return -ENOMEM;
 
 	list_add_tail(&region->list, pos);
-done:
 	return 0;
 }