From: Yang Yingliang yangyingliang@huawei.com
commit 19833c40d0415d6fe4340b5b9c46239abbf718f6 upstream.
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: 32f171724e5c ("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 Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/iio/industrialio-core.c | 1 + 1 file changed, 1 insertion(+)
--- a/drivers/iio/industrialio-core.c +++ b/drivers/iio/industrialio-core.c @@ -1597,6 +1597,7 @@ static void iio_device_unregister_sysfs( 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)