From: Tomasz Duszynski tomasz.duszynski@octakon.com
commit 901f84de0e16bde10a72d7eb2f2eb73fcde8fa1a upstream.
Currently ioctl handlers are removed twice. For the first time during iio_device_unregister() then later on inside iio_device_unregister_eventset() and iio_buffers_free_sysfs_and_mask(). Double free leads to kernel panic.
Fix this by not touching ioctl handlers list directly but rather letting code responsible for registration call the matching cleanup routine itself.
Fixes: 8dedcc3eee3ac ("iio: core: centralize ioctl() calls to the main chardev") Signed-off-by: Tomasz Duszynski tomasz.duszynski@octakon.com Acked-by: Alexandru Ardelean ardeleanalex@gmail.com Cc: Stable@vger.kernel.org Link: https://lore.kernel.org/r/20210423080244.2790-1-tomasz.duszynski@octakon.com Signed-off-by: Jonathan Cameron Jonathan.Cameron@huawei.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/iio/industrialio-core.c | 6 ------ 1 file changed, 6 deletions(-)
--- a/drivers/iio/industrialio-core.c +++ b/drivers/iio/industrialio-core.c @@ -1863,9 +1863,6 @@ EXPORT_SYMBOL(__iio_device_register); **/ void iio_device_unregister(struct iio_dev *indio_dev) { - struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(indio_dev); - struct iio_ioctl_handler *h, *t; - cdev_device_del(&indio_dev->chrdev, &indio_dev->dev);
mutex_lock(&indio_dev->info_exist_lock); @@ -1876,9 +1873,6 @@ void iio_device_unregister(struct iio_de
indio_dev->info = NULL;
- list_for_each_entry_safe(h, t, &iio_dev_opaque->ioctl_handlers, entry) - list_del(&h->entry); - iio_device_wakeup_eventset(indio_dev); iio_buffer_wakeup_poll(indio_dev);