drm: Reject getfb for multi-plane framebuffers

getfb can only return a single plane, so reject attempts to use it with
multi-plane framebuffers.

Signed-off-by: Daniel Stone <daniels@collabora.com>
Reported-by: Daniel van Vugt <daniel.van.vugt@canonical.com>
Reviewed-by: Rob Clark <robdclark@gmail.com>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Fixes: 308e5bcbdb10 ("drm: add an fb creation ioctl that takes a pixel format v5")
Cc: stable@vger.kernel.org # v3.3+
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=105518
Link: https://patchwork.freedesktop.org/patch/msgid/20180320225839.30905-1-daniels@collabora.com

1 files changed, 7 insertions, 0 deletions

diff --git a/drivers/gpu/drm/drm_framebuffer.c b/drivers/gpu/drm/drm_framebuffer.c
index c0530a1af5e3..2dc5e8bed172 100644
--- a/drivers/gpu/drm/drm_framebuffer.c
+++ b/drivers/gpu/drm/drm_framebuffer.c
@@ -461,6 +461,12 @@ int drm_mode_getfb(struct drm_device *dev,
         if (!fb)
                 return -ENOENT;
 
+        /* Multi-planar framebuffers need getfb2. */
+        if (fb->format->num_planes > 1) {
+                ret = -EINVAL;
+                goto out;
+        }
+
         r->height = fb->height;
         r->width = fb->width;
         r->depth = fb->format->depth;
@@ -484,6 +490,7 @@ int drm_mode_getfb(struct drm_device *dev,
                 ret = -ENODEV;
         }
 
+out:
         drm_framebuffer_put(fb);
 
         return ret;