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From:   Xiongfeng Wang <wangxiongfeng2@huawei.com>
To:     <wim@linux-watchdog.org>, <linux@roeck-us.net>
CC:     <linux-kernel@vger.kernel.org>, <yangyingliang@huawei.com>,
        <wangxiongfeng2@huawei.com>
Subject: [PATCH] watchdog: sp5100_tco: Fix PCI device refcount leak
Date:   Tue, 22 Nov 2022 19:56:51 +0800
Message-ID: <20221122115651.33877-1-wangxiongfeng2@huawei.com>
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for_each_pci_dev() is implemented by pci_get_device(). The comment of
pci_get_device() says that it will increase the reference count for the
returned pci_dev and also decrease the reference count for the input
pci_dev @from if it is not NULL.

If we break out for_each_pci_dev() loop with pdev not NULL, we need to
call pci_dev_put() to decrease the reference count. Add the missing
pci_dev_put() in error path of sp5100_tco_init() and also when we unload
module.

Fixes: 15e28bf13008 ("watchdog: Add support for sp5100 chipset TCO")
Signed-off-by: Xiongfeng Wang <wangxiongfeng2@huawei.com>
---
 drivers/watchdog/sp5100_tco.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/drivers/watchdog/sp5100_tco.c b/drivers/watchdog/sp5100_tco.c
index fb426b7d81da..f00f26f90444 100644
--- a/drivers/watchdog/sp5100_tco.c
+++ b/drivers/watchdog/sp5100_tco.c
@@ -599,7 +599,7 @@ static int __init sp5100_tco_init(void)
 
 	err = platform_driver_register(&sp5100_tco_driver);
 	if (err)
-		return err;
+		goto put_dev;
 
 	sp5100_tco_platform_device =
 		platform_device_register_simple(TCO_DRIVER_NAME, -1, NULL, 0);
@@ -612,6 +612,8 @@ static int __init sp5100_tco_init(void)
 
 unreg_platform_driver:
 	platform_driver_unregister(&sp5100_tco_driver);
+put_dev:
+	pci_dev_put(sp5100_tco_pci);
 	return err;
 }
 
@@ -619,6 +621,7 @@ static void __exit sp5100_tco_exit(void)
 {
 	platform_device_unregister(sp5100_tco_platform_device);
 	platform_driver_unregister(&sp5100_tco_driver);
+	pci_dev_put(sp5100_tco_pci);
 }
 
 module_init(sp5100_tco_init);
-- 
2.20.1