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From:   Zheng Yongjun <zhengyongjun3@huawei.com>
To:     <davem@davemloft.net>, <kuba@kernel.org>, <netdev@vger.kernel.org>,
        <linux-arm-kernel@lists.infradead.org>,
        <linux-kernel@vger.kernel.org>
CC:     <lars.povlsen@microchip.com>, <Steen.Hegelund@microchip.com>,
        <UNGLinuxDriver@microchip.com>
Subject: [PATCH] net: sparx5: switchdev: fix possible NULL pointer dereference
Date:   Sat, 26 Mar 2022 08:12:39 +0000
Message-ID: <20220326081239.9168-1-zhengyongjun3@huawei.com>
MIME-Version: 1.0
Content-Type: text/plain
Precedence: bulk

As the possible failure of the allocation, devm_kzalloc() may return NULL
pointer.
Therefore, it should be better to check the 'db' in order to prevent
the dereference of NULL pointer.

Fixes: 10615907e9b51 ("net: sparx5: switchdev: adding frame DMA functionality")
Signed-off-by: Zheng Yongjun <zhengyongjun3@huawei.com>
---
 drivers/net/ethernet/microchip/sparx5/sparx5_fdma.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/net/ethernet/microchip/sparx5/sparx5_fdma.c b/drivers/net/ethernet/microchip/sparx5/sparx5_fdma.c
index 7436f62fa152..174ad95e746a 100644
--- a/drivers/net/ethernet/microchip/sparx5/sparx5_fdma.c
+++ b/drivers/net/ethernet/microchip/sparx5/sparx5_fdma.c
@@ -420,6 +420,8 @@ static int sparx5_fdma_tx_alloc(struct sparx5 *sparx5)
 			db_hw->dataptr = phys;
 			db_hw->status = 0;
 			db = devm_kzalloc(sparx5->dev, sizeof(*db), GFP_KERNEL);
+			if (!db)
+				return -ENOMEM;
 			db->cpu_addr = cpu_addr;
 			list_add_tail(&db->list, &tx->db_list);
 		}
-- 
2.17.1