vmwgfx: Disallow user space to send present and readback commands

Signed-off-by: Jakob Bornecrantz <jakob@vmware.com>
Reviewed-by: Thomas Hellstrom <thellstrom@vmware.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>

1 files changed, 13 insertions, 3 deletions

diff --git a/drivers/gpu/drm/vmwgfx/vmwgfx_execbuf.c b/drivers/gpu/drm/vmwgfx/vmwgfx_execbuf.c
index c98c3475a9f8..dea0474f6f3b 100644
--- a/drivers/gpu/drm/vmwgfx/vmwgfx_execbuf.c
+++ b/drivers/gpu/drm/vmwgfx/vmwgfx_execbuf.c
@@ -197,6 +197,12 @@ static int vmw_cmd_blt_surf_screen_check(struct vmw_private *dev_priv,
         } *cmd;
 
         cmd = container_of(header, struct vmw_sid_cmd, header);
+
+        if (unlikely(!sw_context->kernel)) {
+                DRM_ERROR("Kernel only SVGA3d command: %u.\n", cmd->header.id);
+                return -EPERM;
+        }
+
         return vmw_cmd_sid_check(dev_priv, sw_context, &cmd->body.srcImage.sid);
 }
 
@@ -210,6 +216,12 @@ static int vmw_cmd_present_check(struct vmw_private *dev_priv,
         } *cmd;
 
         cmd = container_of(header, struct vmw_sid_cmd, header);
+
+        if (unlikely(!sw_context->kernel)) {
+                DRM_ERROR("Kernel only SVGA3d command: %u.\n", cmd->header.id);
+                return -EPERM;
+        }
+
         return vmw_cmd_sid_check(dev_priv, sw_context, &cmd->body.sid);
 }
 
@@ -478,14 +490,12 @@ static int vmw_cmd_check_not_3d(struct vmw_private *dev_priv,
                                 void *buf, uint32_t *size)
 {
         uint32_t size_remaining = *size;
-        bool need_kernel = true;
         uint32_t cmd_id;
 
         cmd_id = le32_to_cpu(((uint32_t *)buf)[0]);
         switch (cmd_id) {
         case SVGA_CMD_UPDATE:
                 *size = sizeof(uint32_t) + sizeof(SVGAFifoCmdUpdate);
-                need_kernel = false;
                 break;
         case SVGA_CMD_DEFINE_GMRFB:
                 *size = sizeof(uint32_t) + sizeof(SVGAFifoCmdDefineGMRFB);
@@ -507,7 +517,7 @@ static int vmw_cmd_check_not_3d(struct vmw_private *dev_priv,
                 return -EINVAL;
         }
 
-        if (unlikely(need_kernel && !sw_context->kernel)) {
+        if (unlikely(!sw_context->kernel)) {
                 DRM_ERROR("Kernel only SVGA command: %u.\n", cmd_id);
                 return -EPERM;
         }