Hold ctrl device lock in rpmsg_ctrldev_remove to avoid any new create ept call to proceed, otherwise new ept creation and associted char device may suceed. Any further call from user space for rpmsg_eptdev_open will reference already freed rpdev and will result in crash. Below crash signature was observed - rpmsg_create_ept+0x40/0xa0 rpmsg_eptdev_open+0x88/0x138 chrdev_open+0xc4/0x1c8 do_dentry_open+0x230/0x378 vfs_open+0x3c/0x48 path_openat+0x93c/0xa78 do_filp_open+0x98/0x118 do_sys_openat2+0x90/0x220 do_sys_open+0x64/0x8c Signed-off-by: Deepak Kumar Singh <quic_deesin@xxxxxxxxxxx> --- 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
