iio: core: fix double free in iio_device_unregister_sysfs()

I got the double free report:

BUG: KASAN: double-free or invalid-free in kfree+0xce/0x390
 iio_device_unregister_sysfs+0x108/0x13b [industrialio]
 iio_dev_release+0x9e/0x10e [industrialio]
 device_release+0xa5/0x240

If __iio_device_register() fails, iio_dev_opaque->groups will be freed
in error path in iio_device_unregister_sysfs(), then iio_dev_release()
will call iio_device_unregister_sysfs() again, it causes double free.
Set iio_dev_opaque->groups to NULL when it's freed to fix this double free.

Not this is a local work around for a more general mess around life time
management that will get cleaned up and should make this handling
unnecesarry.

Fixes: 32f171724e ("iio: core: rework iio device group creation")
Reported-by: Hulk Robot <hulkci@huawei.com>
Reviewed-by: Alexandru Ardelean <ardeleanalex@gmail.com>
Signed-off-by: Yang Yingliang <yangyingliang@huawei.com>
Link: https://lore.kernel.org/r/20211013030532.956133-1-yangyingliang@huawei.com
Cc: <Stable@vger.kernel.org>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
This commit is contained in:
Yang Yingliang 2021-10-13 11:05:32 +08:00 committed by Jonathan Cameron
parent fe6f45f6ba
commit 19833c40d0

View File

@ -1600,6 +1600,7 @@ static void iio_device_unregister_sysfs(struct iio_dev *indio_dev)
kfree(iio_dev_opaque->chan_attr_group.attrs);
iio_dev_opaque->chan_attr_group.attrs = NULL;
kfree(iio_dev_opaque->groups);
iio_dev_opaque->groups = NULL;
}
static void iio_dev_release(struct device *device)