Messages in this thread Patch in this message | | | From | Kamal Mostafa <> | Subject | [PATCH 3.13.y-ckt 39/90] iio: core: Fix double free. | Date | Tue, 5 May 2015 13:54:11 -0700 |
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3.13.11-ckt20 -stable review patch. If anyone has any objections, please let me know.
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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: Kamal Mostafa <kamal@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 18f72e3..6e4858d 100644 --- a/drivers/iio/industrialio-core.c +++ b/drivers/iio/industrialio-core.c @@ -812,8 +812,7 @@ 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) { @@ -821,6 +820,7 @@ 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); } } @@ -901,6 +901,7 @@ 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 c531839..7c35689 100644 --- a/drivers/iio/industrialio-event.c +++ b/drivers/iio/industrialio-event.c @@ -596,6 +596,7 @@ 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; error_ret: return ret; -- 1.9.1
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