[Patch Part1 V2 14/20] iommu/vt-d: avoid double free in error recovery path

[Jiang Liu <jiang.liu@linux.intel.com>]

The g_iommus array will be freed twice when failed to initialize IOMMU
devices, which will cause system panic.

Signed-off-by: Jiang Liu <jiang.liu@linux.intel.com>
---
 drivers/iommu/intel-iommu.c |   14 +++-----------
 1 file changed, 3 insertions(+), 11 deletions(-)

diff --git a/drivers/iommu/intel-iommu.c b/drivers/iommu/intel-iommu.c
index cbdb1ff..1a20171 100644
--- a/drivers/iommu/intel-iommu.c
+++ b/drivers/iommu/intel-iommu.c
@@ -1293,19 +1293,10 @@ static void free_dmar_iommu(struct intel_iommu *iommu)
 	iommu->domains = NULL;
 	iommu->domain_ids = NULL;
 
-	g_iommus[iommu->seq_id] = NULL;
-
-	/* if all iommus are freed, free g_iommus */
-	for (i = 0; i < g_num_of_iommus; i++) {
-		if (g_iommus[i])
-			break;
-	}
-
-	if (i == g_num_of_iommus)
-		kfree(g_iommus);
-
 	/* free context mapping */
 	free_context_table(iommu);
+
+	g_iommus[iommu->seq_id] = NULL;
 }
 
 static struct dmar_domain *alloc_domain(void)
@@ -2621,6 +2612,7 @@ error:
 	for_each_active_iommu(iommu, drhd)
 		free_dmar_iommu(iommu);
 	kfree(g_iommus);
+	g_iommus = NULL;
 	return ret;
 }
 
-- 
1.7.10.4