This is a note to let you know that I've just added the patch titled
iio: core: Fix double free.
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 c1b03ab5e886760bdd38c9c7a27af149046ffe01 Mon Sep 17 00:00:00 2001
From: Martin Fuzzey <mfuzzey@xxxxxxxxxxx>
Date: Thu, 19 Feb 2015 15:17:44 +0100
Subject: 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@xxxxxxxxxxx>
Cc: <Stable@xxxxxxxxxxxxxxx>
Signed-off-by: Jonathan Cameron <jic23@xxxxxxxxxx>
---
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 aaba9d3d980e..4df97f650e44 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 a4b397048f71..a99692ba91bc 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;
}
--
2.3.4
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