Commit a428dcf0 authored Oct 28, 2024 by Xiongfeng Wang Committed by Liu Mingrui Oct 28, 2024

gpio: amd8111: Fix PCI device reference count leak

stable inclusion
from stable-v4.19.269
commit b2bc053ebbba57a06fa655db5ea796de2edce445
category: bugfix
bugzilla: https://gitee.com/src-openeuler/kernel/issues/IAYRFI
CVE: CVE-2022-48973

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=b2bc053ebbba57a06fa655db5ea796de2edce445



--------------------------------

[ Upstream commit 45fecdb9 ]

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: f942a7de ("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>
Signed-off-by: Liu Mingrui <liumingrui@huawei.com>

parent 1b77b8cd

drivers/gpio/gpio-amd8111.c

+4 −0

Original line number	Diff line number	Diff line
		@@ -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);