[Intel-gfx] [PATCH i-g-t 4/5] lib/igt_kms: Fix memory corruption when there's no cursor plane

[Brian Starkey]

The dynamic plane support means that if there's no cursor plane, then
there is no space in the pipe->planes array for it, and thus assigning
a "drm_plane-less" plane is out-of-bounds and leads to heap corruption
and later crashes.

The "drm_plane-less" cursor plane isn't included in n_planes anyway,
which means there's no way to ever access it/know that it's there - so
just remove it entirely.

Fixes: 36656239ef96 lib/igt_kms: Implement dynamic plane count support
Signed-off-by: Brian Starkey <brian.starkey at arm.com>
---
 lib/igt_kms.c |    6 ------
 1 file changed, 6 deletions(-)

diff --git a/lib/igt_kms.c b/lib/igt_kms.c
index 45c90c71f301..ef7bfd1a8108 100644
--- a/lib/igt_kms.c
+++ b/lib/igt_kms.c
@@ -1837,12 +1837,6 @@ void igt_display_init(igt_display_t *display, int drm_fd)
 				memset(&pipe->planes[last_plane], 0,
 				       sizeof *plane);
 			}
-		} else {
-			/* Add drm_plane-less cursor */
-			plane = &pipe->planes[p];
-			plane->pipe = pipe;
-			plane->index = p;
-			plane->type = DRM_PLANE_TYPE_CURSOR;
 		}
 
 		pipe->n_planes = n_planes;
-- 
1.7.9.5