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From:   Zhang Zekun <zhangzekun11@huawei.com>
To:     <robin.murphy@arm.com>, <joro@8bytes.org>, <will@kernel.org>
CC:     <iommu@lists.linux.dev>, <linux-kernel@vger.kernel.org>,
        <baolu.lu@linux.intel.com>, <robh@kernel.org>,
        <nicolinc@nvidia.com>, <john.g.garry@oracle.com>,
        <kevin.tian@intel.com>
Subject: [RESEND PATCH 1/2] iommu/iova: Add check for cpu_rcache in free_iova_rcaches
Date:   Fri, 11 Aug 2023 21:02:45 +0800
Message-ID: <20230811130246.42719-2-zhangzekun11@huawei.com>
In-Reply-To: <20230811130246.42719-1-zhangzekun11@huawei.com>
References: <20230811130246.42719-1-zhangzekun11@huawei.com>
MIME-Version: 1.0
Content-Type: text/plain
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free_iova_rcaches() needs to check if cpu_rcache->loaded and
cpu_rcache->prev is NULL before freeing them. Because
iova_domain_init_rcaches() may fail to alloc magazine for
cpu_rcache->loaded and cpu_rcache->prev, but they will be freed
for all cpus.

Fixes: 32e92d9f6f87 ("iommu/iova: Separate out rcache init")
Signed-off-by: Zhang Zekun <zhangzekun11@huawei.com>
---
 drivers/iommu/iova.c | 10 +++++++++-
 1 file changed, 9 insertions(+), 1 deletion(-)

diff --git a/drivers/iommu/iova.c b/drivers/iommu/iova.c
index 10b964600948..3c784a28e9ed 100644
--- a/drivers/iommu/iova.c
+++ b/drivers/iommu/iova.c
@@ -746,8 +746,12 @@ int iova_domain_init_rcaches(struct iova_domain *iovad)
 
 			spin_lock_init(&cpu_rcache->lock);
 			cpu_rcache->loaded = iova_magazine_alloc(GFP_KERNEL);
+			if (!cpu_rcache->loaded) {
+				ret = -ENOMEM;
+				goto out_err;
+			}
 			cpu_rcache->prev = iova_magazine_alloc(GFP_KERNEL);
-			if (!cpu_rcache->loaded || !cpu_rcache->prev) {
+			if (!cpu_rcache->prev) {
 				ret = -ENOMEM;
 				goto out_err;
 			}
@@ -903,7 +907,11 @@ static void free_iova_rcaches(struct iova_domain *iovad)
 			break;
 		for_each_possible_cpu(cpu) {
 			cpu_rcache = per_cpu_ptr(rcache->cpu_rcaches, cpu);
+			if (!cpu_rcache->loaded)
+				break;
 			iova_magazine_free(cpu_rcache->loaded);
+			if (!cpu_rcache->prev)
+				break;
 			iova_magazine_free(cpu_rcache->prev);
 		}
 		free_percpu(rcache->cpu_rcaches);
-- 
2.17.1