[PATCH 6.12 196/567] cpufreq: nforce2: fix reference count leak in nforce2

Greg Kroah-Hartman
2026-01-06T17:25:05Z

From: Miaoqian Lin <linmq006@gmail.com>

commit 9600156bb99852c216a2128cdf9f114eb67c350f upstream.

There are two reference count leaks in this driver:

1. In nforce2_fsb_read(): pci_get_subsys() increases the reference count
of the PCI device, but pci_dev_put() is never called to release it,
thus leaking the reference.

2. In nforce2_detect_chipset(): pci_get_subsys() gets a reference to the
nforce2_dev which is stored in a global variable, but the reference
is never released when the module is unloaded.

Fix both by:
- Adding pci_dev_put(nforce2_sub5) in nforce2_fsb_read() after reading
the configuration.
- Adding pci_dev_put(nforce2_dev) in nforce2_exit() to release the
global device reference.

Found via static analysis.

Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Cc: stable@vger.kernel.org
Signed-off-by: Miaoqian Lin <linmq006@gmail.com>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
drivers/cpufreq/cpufreq-nforce2.c | 3 +++
1 file changed, 3 insertions(+)

--- a/drivers/cpufreq/cpufreq-nforce2.c
+++ b/drivers/cpufreq/cpufreq-nforce2.c
@@ -145,6 +145,8 @@ static unsigned int nforce2_fsb_read(int
pci_read_config_dword(nforce2_sub5, NFORCE2_BOOTFSB, &fsb);
fsb /= 1000000;

+ pci_dev_put(nforce2_sub5);
+
/* Check if PLL register is already set */
pci_read_config_byte(nforce2_dev, NFORCE2_PLLENABLE, (u8 *)&temp);

@@ -426,6 +428,7 @@ static int __init nforce2_init(void)
static void __exit nforce2_exit(void)
{
cpufreq_unregister_driver(&nforce2_driver);
+ pci_dev_put(nforce2_dev);
}

module_init(nforce2_init);