Change from v4:
Corrcted mistaked in commit message for patch2.
Deepak Kumar Singh (2):
rpmsg: glink: Add lock to avoid race when rpmsg device is released
rpmsg: glink: Add lock to rpmsg_ctrldev_remove
drivers/rpmsg/rpmsg_char.c | 8 ++++++++
drivers/rpmsg/rpmsg_ctrl.c | 2 ++
2 files changed, 10 insertions(+)
--
2.7.4
Call to rpmsg_ctrldev_ioctl() and rpmsg_ctrldev_remove() must be synchronized.
In present code rpmsg_ctrldev_remove() is not protected with lock, therefore
new char device creation can succeed through rpmsg_ctrldev_ioctl() call. At the
same time call to rpmsg_ctrldev_remove() function for ctrl device removal will
free associated rpdev device. As char device creation already succeeded, user
space is free to issue open() call which maps to rpmsg_create_ept() in kernel.
rpmsg_create_ept() function tries to reference rpdev which has already been
freed through rpmsg_ctrldev_remove(). Issue is predominantly seen in aggressive
reboot tests where rpmsg_ctrldev_ioctl() and rpmsg_ctrldev_remove() can race with
each other.
Adding lock in rpmsg_ctrldev_remove() avoids any new char device creation
through rpmsg_ctrldev_ioctl() while remove call is already in progress.
Signed-off-by: Deepak Kumar Singh <[email protected]>
---
drivers/rpmsg/rpmsg_ctrl.c | 2 ++
1 file changed, 2 insertions(+)
diff --git a/drivers/rpmsg/rpmsg_ctrl.c b/drivers/rpmsg/rpmsg_ctrl.c
index 107da70..4332538 100644
--- a/drivers/rpmsg/rpmsg_ctrl.c
+++ b/drivers/rpmsg/rpmsg_ctrl.c
@@ -194,10 +194,12 @@ static void rpmsg_ctrldev_remove(struct rpmsg_device *rpdev)
struct rpmsg_ctrldev *ctrldev = dev_get_drvdata(&rpdev->dev);
int ret;
+ mutex_lock(&ctrldev->ctrl_lock);
/* Destroy all endpoints */
ret = device_for_each_child(&ctrldev->dev, NULL, rpmsg_chrdev_eptdev_destroy);
if (ret)
dev_warn(&rpdev->dev, "failed to nuke endpoints: %d\n", ret);
+ mutex_unlock(&ctrldev->ctrl_lock);
cdev_device_del(&ctrldev->cdev, &ctrldev->dev);
put_device(&ctrldev->dev);
--
2.7.4
On Mon, Sep 19, 2022 at 04:23:58PM +0530, Deepak Kumar Singh wrote:
> Change from v4:
> Corrcted mistaked in commit message for patch2.
>
> Deepak Kumar Singh (2):
> rpmsg: glink: Add lock to avoid race when rpmsg device is released
> rpmsg: glink: Add lock to rpmsg_ctrldev_remove
>
Why does 'glink' still shows up in this cover letter and the version number wrong?
> drivers/rpmsg/rpmsg_char.c | 8 ++++++++
> drivers/rpmsg/rpmsg_ctrl.c | 2 ++
> 2 files changed, 10 insertions(+)
>
> --
> 2.7.4
>
On Mon, 19 Sep 2022 16:23:58 +0530, Deepak Kumar Singh wrote:
> Change from v4:
> Corrcted mistaked in commit message for patch2.
>
> Deepak Kumar Singh (2):
> rpmsg: glink: Add lock to avoid race when rpmsg device is released
> rpmsg: glink: Add lock to rpmsg_ctrldev_remove
>
> [...]
Applied, thanks!
[1/2] rpmsg: char: Add lock to avoid race when rpmsg device is released
commit: 17b88a2050e9d1f89a53562f2adb709a8959e763
[2/2] rpmsg: ctrl: Add lock to rpmsg_ctrldev_remove
commit: c23965b7f7d99bbb2604f1f02aa26fb6d1d5864d
Best regards,
--
Bjorn Andersson <[email protected]>