In i2c_amd_probe(), amd_mp2_find_device() utilizes driver_find_next_device() which internally calls driver_find_device() to locate the matching device. driver_find_device() increments the reference count of the found device by calling get_device(), but amd_mp2_find_device() fails to call put_device() to decrement the reference count before returning. This results in a reference count leak of the PCI device each time i2c_amd_probe() is executed, which may prevent the device from being properly released and cause a memory leak.
Found by code review.
Cc: stable@vger.kernel.org Fixes: 529766e0a011 ("i2c: Add drivers for the AMD PCIe MP2 I2C controller") Signed-off-by: Ma Ke make24@iscas.ac.cn --- Changes in v3: - kept the temporary variable to store pci_get_drvdata() result before releasing the device reference; Changes in v2: - modified the missing initialization in the patch. Sorry for the omission. --- drivers/i2c/busses/i2c-amd-mp2-pci.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-)
diff --git a/drivers/i2c/busses/i2c-amd-mp2-pci.c b/drivers/i2c/busses/i2c-amd-mp2-pci.c index ef7370d3dbea..60edbabc2986 100644 --- a/drivers/i2c/busses/i2c-amd-mp2-pci.c +++ b/drivers/i2c/busses/i2c-amd-mp2-pci.c @@ -458,13 +458,16 @@ struct amd_mp2_dev *amd_mp2_find_device(void) { struct device *dev; struct pci_dev *pci_dev; + struct amd_mp2_dev *mp2_dev;
dev = driver_find_next_device(&amd_mp2_pci_driver.driver, NULL); if (!dev) return NULL;
pci_dev = to_pci_dev(dev); - return (struct amd_mp2_dev *)pci_get_drvdata(pci_dev); + mp2_dev = (struct amd_mp2_dev *)pci_get_drvdata(pci_dev); + put_device(dev); + return mp2_dev; } EXPORT_SYMBOL_GPL(amd_mp2_find_device);