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authorMartin Fuzzey <mfuzzey@parkeon.com>2015-02-19 15:17:44 +0100
committerJonathan Cameron <jic23@kernel.org>2015-03-14 18:54:14 +0000
commitc1b03ab5e886760bdd38c9c7a27af149046ffe01 (patch)
treead8d671b87c667e8eeb4e6ae97811132cecfddbe
parentaf5e1a68318e2ed2de22fc2d7a02f2882abe073c (diff)
downloadop-kernel-dev-c1b03ab5e886760bdd38c9c7a27af149046ffe01.zip
op-kernel-dev-c1b03ab5e886760bdd38c9c7a27af149046ffe01.tar.gz
iio: core: Fix double free.
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> Cc: <Stable@vger.kernel.org> Signed-off-by: Jonathan Cameron <jic23@kernel.org>
-rw-r--r--drivers/iio/industrialio-core.c5
-rw-r--r--drivers/iio/industrialio-event.c1
2 files changed, 4 insertions, 2 deletions
diff --git a/drivers/iio/industrialio-core.c b/drivers/iio/industrialio-core.c
index aaba9d3..4df97f6 100644
--- a/drivers/iio/industrialio-core.c
+++ b/drivers/iio/industrialio-core.c
@@ -847,8 +847,7 @@ 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)
{
@@ -856,6 +855,7 @@ 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);
}
}
@@ -936,6 +936,7 @@ 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 a4b3970..a99692b 100644
--- a/drivers/iio/industrialio-event.c
+++ b/drivers/iio/industrialio-event.c
@@ -500,6 +500,7 @@ 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;
}
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