Commit 9600156b authored Oct 27, 2025 by Miaoqian Lin Committed by Viresh Kumar Oct 28, 2025

cpufreq: nforce2: fix reference count leak in nforce2



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: 1da177e4 ("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>

parent 85976d37

drivers/cpufreq/cpufreq-nforce2.c

+3 −0

Original line number	Diff line number	Diff line
		@@ -145,6 +145,8 @@ static unsigned int nforce2_fsb_read(int bootfsb)
		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);