[PATCH] watchdog: sp5100_tco: Fix pci_dev reference leak in sp5100_tco_init()

[Wentao Liang]

sp5100_tco_init() stores the PCI device matched by for_each_pci_dev()
in the global sp5100_tco_pci and keeps its reference for the lifetime
of the driver, but neither sp5100_tco_exit() nor the error paths of
sp5100_tco_init() call pci_dev_put(), leaking the reference on driver
registration failure and on every module load/unload cycle.

Drop the reference when the platform driver or device registration
fails and when the module is unloaded.

Fixes: 15e28bf13008 ("watchdog: Add support for sp5100 chipset TCO")
Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Wentao Liang <vulab@xxxxxxxxxxx>
---
 drivers/watchdog/sp5100_tco.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/drivers/watchdog/sp5100_tco.c b/drivers/watchdog/sp5100_tco.c
index 2bd3dc25cb03..3562d5ec63c1 100644
--- a/drivers/watchdog/sp5100_tco.c
+++ b/drivers/watchdog/sp5100_tco.c
@@ -604,8 +604,10 @@ static int __init sp5100_tco_init(void)
 	pr_info("SP5100/SB800 TCO WatchDog Timer Driver\n");
 
 	err = platform_driver_register(&sp5100_tco_driver);
-	if (err)
+	if (err) {
+		pci_dev_put(sp5100_tco_pci);
 		return err;
+	}
 
 	sp5100_tco_platform_device =
 		platform_device_register_simple(TCO_DRIVER_NAME, -1, NULL, 0);
@@ -618,6 +620,7 @@ static int __init sp5100_tco_init(void)
 
 unreg_platform_driver:
 	platform_driver_unregister(&sp5100_tco_driver);
+	pci_dev_put(sp5100_tco_pci);
 	return err;
 }
 
@@ -625,6 +628,7 @@ 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);
-- 
2.34.1