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From:   Xiongfeng Wang <wangxiongfeng2@huawei.com>
To:     <arnd@arndb.de>, <gregkh@linuxfoundation.org>
CC:     <linux-kernel@vger.kernel.org>, <yangyingliang@huawei.com>,
        <wangxiongfeng2@huawei.com>
Subject: [PATCH] applicom: Fix PCI device refcount leak in applicom_init()
Date:   Tue, 22 Nov 2022 19:40:35 +0800
Message-ID: <20221122114035.24194-1-wangxiongfeng2@huawei.com>
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Precedence: bulk

As comment of pci_get_class() says, it returns a pci_device with its
refcount increased and decreased the refcount for the input parameter
@from if it is not NULL.

If we break the loop in applicom_init() with 'dev' not NULL, we need to
call pci_dev_put() to decrease the refcount. Add the missing
pci_dev_put() to avoid refcount leak.

Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Signed-off-by: Xiongfeng Wang <wangxiongfeng2@huawei.com>
---
 drivers/char/applicom.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/drivers/char/applicom.c b/drivers/char/applicom.c
index 36203d3fa6ea..69314532f38c 100644
--- a/drivers/char/applicom.c
+++ b/drivers/char/applicom.c
@@ -197,8 +197,10 @@ static int __init applicom_init(void)
 		if (!pci_match_id(applicom_pci_tbl, dev))
 			continue;
 		
-		if (pci_enable_device(dev))
+		if (pci_enable_device(dev)) {
+			pci_dev_put(dev);
 			return -EIO;
+		}
 
 		RamIO = ioremap(pci_resource_start(dev, 0), LEN_RAM_IO);
 
@@ -207,6 +209,7 @@ static int __init applicom_init(void)
 				"space at 0x%llx\n",
 				(unsigned long long)pci_resource_start(dev, 0));
 			pci_disable_device(dev);
+			pci_dev_put(dev);
 			return -EIO;
 		}
 
-- 
2.20.1