On Mon, Apr 13, 2015 at 11:06:13AM -0700, Matt Roper wrote:
Our legacy SetPlane updates perform integer overflow checking on a plane's destination rectangle in drm_mode_setplane(), and atomic updates handled as part of a drm_atomic_state transaction do the same checking in drm_atomic_plane_check(). However legacy cursor updates that get routed through universal plane interfaces may bypass this overflow checking if the driver's .update_plane is serviced by the transitional plane helpers rather than the full atomic plane helpers.
Move the check for destination rectangle integer overflow from the drm_mode_setplane() to __setplane_internal() so that it also covers cursor operations.
This fixes an issue first noticed with i915 commit:
commit ff42e093e9c9c17a6e1d6aab24875a36795f926e Author: Daniel Vetter <daniel.vetter@ffwll.ch> Date: Mon Mar 2 16:35:20 2015 +0100 Revert "drm/i915: Switch planes from transitional helpers to full atomic helpers"The above revert switched us from full atomic helpers back to the transitional helpers, and in doing so we lost the overflow checking here for universal cursor updates. Even though such extreme cursor positions are unlikely to actually happen in the wild, we still don't want there to be a change of behavior when drivers switch from transitional helpers to full helpers.
v2: Move check from setplane ioctl to setplane_internal rather than adding an additional copy of the checks to the transitional plane helpers. (Daniel)
Cc: Daniel Vetter daniel@ffwll.ch Testcase: igt/kms_cursor_crc Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=84269 Signed-off-by: Matt Roper matthew.d.roper@intel.com
Applied to drm-misc, thanks. -Daniel
drivers/gpu/drm/drm_crtc.c | 22 +++++++++++----------- 1 file changed, 11 insertions(+), 11 deletions(-)
diff --git a/drivers/gpu/drm/drm_crtc.c b/drivers/gpu/drm/drm_crtc.c index b914882..160647a 100644 --- a/drivers/gpu/drm/drm_crtc.c +++ b/drivers/gpu/drm/drm_crtc.c @@ -2507,6 +2507,17 @@ static int __setplane_internal(struct drm_plane *plane, goto out; }
- /* Give drivers some help against integer overflows */
- if (crtc_w > INT_MAX ||
crtc_x > INT_MAX - (int32_t) crtc_w ||crtc_h > INT_MAX ||crtc_y > INT_MAX - (int32_t) crtc_h) {DRM_DEBUG_KMS("Invalid CRTC coordinates %ux%u+%d+%d\n",crtc_w, crtc_h, crtc_x, crtc_y);return -ERANGE;- }
- fb_width = fb->width << 16; fb_height = fb->height << 16;
@@ -2591,17 +2602,6 @@ int drm_mode_setplane(struct drm_device *dev, void *data, if (!drm_core_check_feature(dev, DRIVER_MODESET)) return -EINVAL;
- /* Give drivers some help against integer overflows */
- if (plane_req->crtc_w > INT_MAX ||
plane_req->crtc_x > INT_MAX - (int32_t) plane_req->crtc_w ||plane_req->crtc_h > INT_MAX ||plane_req->crtc_y > INT_MAX - (int32_t) plane_req->crtc_h) {DRM_DEBUG_KMS("Invalid CRTC coordinates %ux%u+%d+%d\n",plane_req->crtc_w, plane_req->crtc_h,plane_req->crtc_x, plane_req->crtc_y);return -ERANGE;- }
- /*
- First, find the plane, crtc, and fb objects. If not available,
- we don't bother to call the driver.
-- 1.8.5.1