Commit 1c11289b authored by Iwona Winiarska's avatar Iwona Winiarska
Browse files

peci: cpu: Fix use-after-free in adev_release() 



When auxiliary_device_add() returns an error, auxiliary_device_uninit()
is called, which causes refcount for device to be decremented and
.release callback will be triggered.

Because adev_release() re-calls auxiliary_device_uninit(), it will cause
use-after-free:
[ 1269.455172] WARNING: CPU: 0 PID: 14267 at lib/refcount.c:28 refcount_warn_saturate+0x110/0x15
[ 1269.464007] refcount_t: underflow; use-after-free.

Reported-by: default avatarJianglei Nie <niejianglei2021@163.com>
Signed-off-by: default avatarIwona Winiarska <iwona.winiarska@intel.com>
Link: https://lore.kernel.org/r/20220705101501.298395-1-iwona.winiarska@intel.com
parent e79b548b

drivers/peci/cpu.c

+1 −2
Original line number Diff line number Diff line
@@ -188,8 +188,6 @@ static void adev_release(struct device *dev) 
{

	struct auxiliary_device *adev = to_auxiliary_dev(dev);



	auxiliary_device_uninit(adev);



	kfree(adev->name);

	kfree(adev);

}
@@ -234,6 +232,7 @@ static void unregister_adev(void *_adev) 
	struct auxiliary_device *adev = _adev;



	auxiliary_device_delete(adev);

	auxiliary_device_uninit(adev);

}



static int devm_adev_add(struct device *dev, int idx)