| From | Luis Henriques <> | Subject | [PATCH 3.16.y-ckt 108/144] iio: core: Fix double free. | Date | Tue, 21 Apr 2015 16:31:33 +0100 |
| |
3.16.7-ckt10 -stable review patch. If anyone has any objections, please let me know.
------------------
From: Martin Fuzzey <mfuzzey@parkeon.com>
commit c1b03ab5e886760bdd38c9c7a27af149046ffe01 upstream.
When an error occurred during event registration memory was freed twice resulting in kernel memory corruption and a crash in unrelated code.
The problem was caused by iio_device_unregister_eventset() iio_device_unregister_sysfs()
being called twice, once on the error path and then again via iio_dev_release().
Fix this by making these two functions idempotent so they may be called multiple times.
The problem was observed before applying 78b33216 iio:core: Handle error when mask type is not separate
Signed-off-by: Martin Fuzzey <mfuzzey@parkeon.com> Signed-off-by: Jonathan Cameron <jic23@kernel.org> Signed-off-by: Luis Henriques <luis.henriques@canonical.com> --- drivers/iio/industrialio-core.c | 5 +++-- drivers/iio/industrialio-event.c | 1 + 2 files changed, 4 insertions(+), 2 deletions(-)
diff --git a/drivers/iio/industrialio-core.c b/drivers/iio/industrialio-core.c index 4b1f375c5659..fa061972a2fe 100644 --- a/drivers/iio/industrialio-core.c +++ b/drivers/iio/industrialio-core.c @@ -828,8 +828,7 @@ static int iio_device_add_channel_sysfs(struct iio_dev *indio_dev, * @attr_list: List of IIO device attributes * * This function frees the memory allocated for each of the IIO device - * attributes in the list. Note: if you want to reuse the list after calling - * this function you have to reinitialize it using INIT_LIST_HEAD(). + * attributes in the list. */ void iio_free_chan_devattr_list(struct list_head *attr_list) { @@ -837,6 +836,7 @@ void iio_free_chan_devattr_list(struct list_head *attr_list) list_for_each_entry_safe(p, n, attr_list, l) { kfree(p->dev_attr.attr.name); + list_del(&p->l); kfree(p); } } @@ -917,6 +917,7 @@ static void iio_device_unregister_sysfs(struct iio_dev *indio_dev) iio_free_chan_devattr_list(&indio_dev->channel_attr_list); kfree(indio_dev->chan_attr_group.attrs); + indio_dev->chan_attr_group.attrs = NULL; } static void iio_dev_release(struct device *device) diff --git a/drivers/iio/industrialio-event.c b/drivers/iio/industrialio-event.c index bfbf4d419f41..ad7a35f63a16 100644 --- a/drivers/iio/industrialio-event.c +++ b/drivers/iio/industrialio-event.c @@ -492,6 +492,7 @@ int iio_device_register_eventset(struct iio_dev *indio_dev) error_free_setup_event_lines: iio_free_chan_devattr_list(&indio_dev->event_interface->dev_attr_list); kfree(indio_dev->event_interface); + indio_dev->event_interface = NULL; return ret; }
|