[PATCH 4.9 16/31] gpio: amd8111: Fix PCI device reference count leak

Greg Kroah-Hartman
2022-12-12T13:56:05Z

From: Xiongfeng Wang <wangxiongfeng2@huawei.com>

[ Upstream commit 45fecdb9f658d9c82960c98240bc0770ade19aca ]

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 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() after the 'out' label. Since pci_dev_put() can handle NULL
input parameter, there is no problem for the 'Device not found' branch.
For the normal path, add pci_dev_put() in amd_gpio_exit().

Fixes: f942a7de047d ("gpio: add a driver for GPIO pins found on AMD-8111 south bridge chips")
Signed-off-by: Xiongfeng Wang <wangxiongfeng2@huawei.com>
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/gpio/gpio-amd8111.c | 4 ++++
1 file changed, 4 insertions(+)

diff --git a/drivers/gpio/gpio-amd8111.c b/drivers/gpio/gpio-amd8111.c
index 30ad7d7c1678..f8486bac12d0 100644
--- a/drivers/gpio/gpio-amd8111.c
+++ b/drivers/gpio/gpio-amd8111.c
@@ -231,7 +231,10 @@ static int __init amd_gpio_init(void)
ioport_unmap(gp.pm);
goto out;
}
+ return 0;
+
out:
+ pci_dev_put(pdev);
return err;
}

@@ -239,6 +242,7 @@ static void __exit amd_gpio_exit(void)
{
gpiochip_remove(&gp.chip);
ioport_unmap(gp.pm);
+ pci_dev_put(gp.pdev);
}

module_init(amd_gpio_init);
--
2.35.1