diff options
| author | Deepak Kumar Singh <quic_deesin@quicinc.com> | 2022-09-19 16:24:00 +0530 |
|---|---|---|
| committer | Bjorn Andersson <andersson@kernel.org> | 2022-12-28 09:54:03 -0600 |
| commit | c23965b7f7d99bbb2604f1f02aa26fb6d1d5864d (patch) | |
| tree | c1018d6da20e4c0a4c7e3832000efc2451583b0a /drivers/rpmsg | |
| parent | 17b88a2050e9d1f89a53562f2adb709a8959e763 (diff) | |
rpmsg: ctrl: Add lock to rpmsg_ctrldev_remove
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 <quic_deesin@quicinc.com>
Signed-off-by: Bjorn Andersson <andersson@kernel.org>
Link: https://lore.kernel.org/r/1663584840-15762-3-git-send-email-quic_deesin@quicinc.com
Diffstat (limited to 'drivers/rpmsg')
| -rw-r--r-- | drivers/rpmsg/rpmsg_ctrl.c | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/drivers/rpmsg/rpmsg_ctrl.c b/drivers/rpmsg/rpmsg_ctrl.c index 107da70fdbaa..433253835690 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); |