[PATCH 2/2] iommu/vt-d: Fix potential memory leak in intel_setup_irq_remapping()

[Lu Baolu <baolu.lu@linux.intel.com>]

From: Guoqing Jiang <guoqing.jiang@linux.dev>

After commit e3beca48a45b ("irqdomain/treewide: Keep firmware node
unconditionally allocated"). For tear down scenario, fn is only freed
after fail to allocate ir_domain, though it also should be freed in case
dmar_enable_qi returns error.

Besides free fn, irq_domain and ir_msi_domain need to be removed as well
if intel_setup_irq_remapping fails to enable queued invalidation.

Improve the rewinding path by add out_free_ir_domain and out_free_fwnode
lables per Baolu's suggestion.

Fixes: e3beca48a45b ("irqdomain/treewide: Keep firmware node unconditionally allocated")
Suggested-by: Lu Baolu <baolu.lu@linux.intel.com>
Signed-off-by: Guoqing Jiang <guoqing.jiang@linux.dev>
Link: https://lore.kernel.org/r/20220119063640.16864-1-guoqing.jiang@linux.dev
Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
---
 drivers/iommu/intel/irq_remapping.c | 13 ++++++++++---
 1 file changed, 10 insertions(+), 3 deletions(-)

diff --git a/drivers/iommu/intel/irq_remapping.c b/drivers/iommu/intel/irq_remapping.c
index f912fe45bea2..a67319597884 100644
--- a/drivers/iommu/intel/irq_remapping.c
+++ b/drivers/iommu/intel/irq_remapping.c
@@ -569,9 +569,8 @@ static int intel_setup_irq_remapping(struct intel_iommu *iommu)
 					    fn, &intel_ir_domain_ops,
 					    iommu);
 	if (!iommu->ir_domain) {
-		irq_domain_free_fwnode(fn);
 		pr_err("IR%d: failed to allocate irqdomain\n", iommu->seq_id);
-		goto out_free_bitmap;
+		goto out_free_fwnode;
 	}
 	iommu->ir_msi_domain =
 		arch_create_remap_msi_irq_domain(iommu->ir_domain,
@@ -595,7 +594,7 @@ static int intel_setup_irq_remapping(struct intel_iommu *iommu)
 
 		if (dmar_enable_qi(iommu)) {
 			pr_err("Failed to enable queued invalidation\n");
-			goto out_free_bitmap;
+			goto out_free_ir_domain;
 		}
 	}
 
@@ -619,6 +618,14 @@ static int intel_setup_irq_remapping(struct intel_iommu *iommu)
 
 	return 0;
 
+out_free_ir_domain:
+	if (iommu->ir_msi_domain)
+		irq_domain_remove(iommu->ir_msi_domain);
+	iommu->ir_msi_domain = NULL;
+	irq_domain_remove(iommu->ir_domain);
+	iommu->ir_domain = NULL;
+out_free_fwnode:
+	irq_domain_free_fwnode(fn);
 out_free_bitmap:
 	bitmap_free(bitmap);
 out_free_pages:
-- 
2.25.1

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