From 1899bd57570a3e610db574b57d1e7e66378aa908 Mon Sep 17 00:00:00 2001 From: Marek Szyprowski Date: Wed, 12 Jul 2017 12:09:22 +0200 Subject: drm/exynos: forbid creating framebuffers from too small GEM buffers Add a check if the framebuffer described by the provided drm_mode_fb_cmd2 structure fits into provided GEM buffers. Without this check it is possible to create a framebuffer object from a small buffer and set it to the hardware, what results in displaying system memory outside the allocated GEM buffer. Signed-off-by: Marek Szyprowski Reviewed-by: Tobias Jakobi Signed-off-by: Inki Dae --- drivers/gpu/drm/exynos/exynos_drm_fb.c | 14 +++++++++++++- 1 file changed, 13 insertions(+), 1 deletion(-) (limited to 'drivers') diff --git a/drivers/gpu/drm/exynos/exynos_drm_fb.c b/drivers/gpu/drm/exynos/exynos_drm_fb.c index d48fd7c918f8..73217c281c9a 100644 --- a/drivers/gpu/drm/exynos/exynos_drm_fb.c +++ b/drivers/gpu/drm/exynos/exynos_drm_fb.c @@ -145,13 +145,19 @@ static struct drm_framebuffer * exynos_user_fb_create(struct drm_device *dev, struct drm_file *file_priv, const struct drm_mode_fb_cmd2 *mode_cmd) { + const struct drm_format_info *info = drm_get_format_info(dev, mode_cmd); struct exynos_drm_gem *exynos_gem[MAX_FB_BUFFER]; struct drm_gem_object *obj; struct drm_framebuffer *fb; int i; int ret; - for (i = 0; i < drm_format_num_planes(mode_cmd->pixel_format); i++) { + for (i = 0; i < info->num_planes; i++) { + unsigned int height = (i == 0) ? mode_cmd->height : + DIV_ROUND_UP(mode_cmd->height, info->vsub); + unsigned long size = height * mode_cmd->pitches[i] + + mode_cmd->offsets[i]; + obj = drm_gem_object_lookup(file_priv, mode_cmd->handles[i]); if (!obj) { DRM_ERROR("failed to lookup gem object\n"); @@ -160,6 +166,12 @@ exynos_user_fb_create(struct drm_device *dev, struct drm_file *file_priv, } exynos_gem[i] = to_exynos_gem(obj); + + if (size > exynos_gem[i]->size) { + i++; + ret = -EINVAL; + goto err; + } } fb = exynos_drm_framebuffer_init(dev, mode_cmd, exynos_gem, i); -- cgit v1.2.3