virt: vbox: Implement passing requestor info to the host for VirtualBox 6.0.x

VirtualBox 6.0.x has a new feature where the guest kernel driver passes
info about the origin of the request (e.g. userspace or kernelspace) to
the hypervisor.

If we do not pass this information then when running the 6.0.x userspace
guest-additions tools on a 6.0.x host, some requests will get denied
with a VERR_VERSION_MISMATCH error, breaking vboxservice.service and
the mounting of shared folders marked to be auto-mounted.

This commit implements passing the requestor info to the host, fixing this.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

1 files changed, 23 insertions, 3 deletions

diff --git a/drivers/virt/vboxguest/vboxguest_linux.c b/drivers/virt/vboxguest/vboxguest_linux.c
index 6e2a9619192d..6e8c0f1c1056 100644
--- a/drivers/virt/vboxguest/vboxguest_linux.c
+++ b/drivers/virt/vboxguest/vboxguest_linux.c
@@ -5,6 +5,7 @@
  * Copyright (C) 2006-2016 Oracle Corporation
  */
 
+#include <linux/cred.h>
 #include <linux/input.h>
 #include <linux/kernel.h>
 #include <linux/miscdevice.h>
@@ -28,6 +29,23 @@ static DEFINE_MUTEX(vbg_gdev_mutex);
 /** Global vbg_gdev pointer used by vbg_get/put_gdev. */
 static struct vbg_dev *vbg_gdev;
 
+static u32 vbg_misc_device_requestor(struct inode *inode)
+{
+	u32 requestor = VMMDEV_REQUESTOR_USERMODE |
+			VMMDEV_REQUESTOR_CON_DONT_KNOW |
+			VMMDEV_REQUESTOR_TRUST_NOT_GIVEN;
+
+	if (from_kuid(current_user_ns(), current->cred->uid) == 0)
+		requestor |= VMMDEV_REQUESTOR_USR_ROOT;
+	else
+		requestor |= VMMDEV_REQUESTOR_USR_USER;
+
+	if (in_egroup_p(inode->i_gid))
+		requestor |= VMMDEV_REQUESTOR_GRP_VBOX;
+
+	return requestor;
+}
+
 static int vbg_misc_device_open(struct inode *inode, struct file *filp)
 {
 	struct vbg_session *session;
@@ -36,7 +54,7 @@ static int vbg_misc_device_open(struct inode *inode, struct file *filp)
 	/* misc_open sets filp->private_data to our misc device */
 	gdev = container_of(filp->private_data, struct vbg_dev, misc_device);
 
-	session = vbg_core_open_session(gdev, false);
+	session = vbg_core_open_session(gdev, vbg_misc_device_requestor(inode));
 	if (IS_ERR(session))
 		return PTR_ERR(session);
 
@@ -53,7 +71,8 @@ static int vbg_misc_device_user_open(struct inode *inode, struct file *filp)
 	gdev = container_of(filp->private_data, struct vbg_dev,
 			    misc_device_user);
 
-	session = vbg_core_open_session(gdev, false);
+	session = vbg_core_open_session(gdev, vbg_misc_device_requestor(inode) |
+					      VMMDEV_REQUESTOR_USER_DEVICE);
 	if (IS_ERR(session))
 		return PTR_ERR(session);
 
@@ -115,7 +134,8 @@ static long vbg_misc_device_ioctl(struct file *filp, unsigned int req,
 			 req == VBG_IOCTL_VMMDEV_REQUEST_BIG;
 
 	if (is_vmmdev_req)
-		buf = vbg_req_alloc(size, VBG_IOCTL_HDR_TYPE_DEFAULT);
+		buf = vbg_req_alloc(size, VBG_IOCTL_HDR_TYPE_DEFAULT,
+				    session->requestor);
 	else
 		buf = kmalloc(size, GFP_KERNEL);
 	if (!buf)