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From:   Jerry Snitselaar <jsnitsel@redhat.com>
To:     iommu@lists.linux.dev, linux-kernel@vger.kernel.org
Cc:     Lu Baolu <baolu.lu@linux.intel.com>,
        Joerg Roedel <joro@8bytes.org>, Will Deacon <will@kernel.org>,
        Robin Murphy <robin.murphy@arm.com>
Subject: [PATCH v2] iommu/vt-d: Clean up si_domain in the init_dmars() error path
Date:   Mon, 10 Oct 2022 07:48:42 -0700
Message-Id: <20221010144842.308890-1-jsnitsel@redhat.com>
In-Reply-To: <20221010065608.281860-1-jsnitsel@redhat.com>
References: <20221010065608.281860-1-jsnitsel@redhat.com>
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A splat from kmem_cache_destroy() was seen with a kernel prior to
commit ee2653bbe89d ("iommu/vt-d: Remove domain and devinfo mempool")
when there was a failure in init_dmars(), because the iommu_domain
cache still had objects. While the mempool code is now gone, there
still is a leak of the si_domain memory if init_dmars() fails. So
clean up si_domain in the init_dmars() error path.

Cc: Lu Baolu <baolu.lu@linux.intel.com>
Cc: Joerg Roedel <joro@8bytes.org>
Cc: Will Deacon <will@kernel.org>
Cc: Robin Murphy <robin.murphy@arm.com>
Fixes: 86080ccc223a ("iommu/vt-d: Allocate si_domain in init_dmars()")
Signed-off-by: Jerry Snitselaar <jsnitsel@redhat.com>
---
v2: Set si_domain to NULL after the memory it points to has been freed.

 drivers/iommu/intel/iommu.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/drivers/iommu/intel/iommu.c b/drivers/iommu/intel/iommu.c
index 31bc50e538a3..ecc0b05b2796 100644
--- a/drivers/iommu/intel/iommu.c
+++ b/drivers/iommu/intel/iommu.c
@@ -2400,6 +2400,7 @@ static int __init si_domain_init(int hw)
 
 	if (md_domain_init(si_domain, DEFAULT_DOMAIN_ADDRESS_WIDTH)) {
 		domain_exit(si_domain);
+		si_domain = NULL;
 		return -EFAULT;
 	}
 
@@ -3042,6 +3043,10 @@ static int __init init_dmars(void)
 		disable_dmar_iommu(iommu);
 		free_dmar_iommu(iommu);
 	}
+	if (si_domain) {
+		domain_exit(si_domain);
+		si_domain = NULL;
+	}
 
 	return ret;
 }
-- 
2.37.2