This is a note to let you know that I've just added the patch titled
iio: core: fix ioctl handlers removal
to my staging git tree which can be found at git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging.git in the staging-linus branch.
The patch will show up in the next release of the linux-next tree (usually sometime within the next 24 hours during the week.)
The patch will hopefully also be merged in Linus's tree for the next -rc kernel release.
If you have any questions about this process, please let me know.
From 901f84de0e16bde10a72d7eb2f2eb73fcde8fa1a Mon Sep 17 00:00:00 2001
From: Tomasz Duszynski tomasz.duszynski@octakon.com Date: Fri, 23 Apr 2021 10:02:44 +0200 Subject: iio: core: fix ioctl handlers removal
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 --- drivers/iio/industrialio-core.c | 6 ------ 1 file changed, 6 deletions(-)
diff --git a/drivers/iio/industrialio-core.c b/drivers/iio/industrialio-core.c index d92c58a94fe4..9e59f5da3d28 100644 --- a/drivers/iio/industrialio-core.c +++ b/drivers/iio/industrialio-core.c @@ -1926,9 +1926,6 @@ 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); @@ -1939,9 +1936,6 @@ void iio_device_unregister(struct iio_dev *indio_dev)
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);