virt: vbox: Fix guest capabilities mask check

Check the passed in capabilities against VMMDEV_GUEST_CAPABILITIES_MASK
instead of against VMMDEV_EVENT_VALID_EVENT_MASK.
This tightens the allowed mask from 0x7ff to 0x7.

Fixes: 0ba002bc4393 ("virt: Add vboxguest driver for Virtual Box Guest integration")
Cc: stable@vger.kernel.org
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Link: https://lore.kernel.org/r/20200709120858.63928-3-hdegoede@redhat.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/virt/vboxguest/vboxguest_core.c b/drivers/virt/vboxguest/vboxguest_core.c
index 8fab04e..18ebd7a 100644 (file)
--- a/drivers/virt/vboxguest/vboxguest_core.c
+++ b/drivers/virt/vboxguest/vboxguest_core.c
@@ -1444,7 +1444,7 @@ static int vbg_ioctl_change_guest_capabilities(struct vbg_dev *gdev,
        or_mask = caps->u.in.or_mask;
        not_mask = caps->u.in.not_mask;
 
-       if ((or_mask | not_mask) & ~VMMDEV_EVENT_VALID_EVENT_MASK)
+       if ((or_mask | not_mask) & ~VMMDEV_GUEST_CAPABILITIES_MASK)
                return -EINVAL;
 
        ret = vbg_set_session_capabilities(gdev, session, or_mask, not_mask,

diff --git a/drivers/virt/vboxguest/vmmdev.h b/drivers/virt/vboxguest/vmmdev.h
index 6337b8d..21f4081 100644 (file)
--- a/drivers/virt/vboxguest/vmmdev.h
+++ b/drivers/virt/vboxguest/vmmdev.h
@@ -206,6 +206,8 @@ VMMDEV_ASSERT_SIZE(vmmdev_mask, 24 + 8);
  * not.
  */
 #define VMMDEV_GUEST_SUPPORTS_GRAPHICS                      BIT(2)
+/* The mask of valid capabilities, for sanity checking. */
+#define VMMDEV_GUEST_CAPABILITIES_MASK                      0x00000007U
 
 /** struct vmmdev_hypervisorinfo - Hypervisor info structure. */
 struct vmmdev_hypervisorinfo {