drm: add a check for x/y in drm_mode_setcrtc
legacy setcrtc ioctl does take a 32 bit value which might indeed
overflow
the checks of crtc_req->x > INT_MAX and crtc_req->y > INT_MAX aren't
needed any more with this
v2: -polish the annotation according to Daniel's comment
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Zhao Junwang <zhjwpku@gmail.com>
Cc: stable@vger.kernel.org
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
diff --git a/drivers/gpu/drm/drm_crtc.c b/drivers/gpu/drm/drm_crtc.c
index b9ba061..357bd04 100644
--- a/drivers/gpu/drm/drm_crtc.c
+++ b/drivers/gpu/drm/drm_crtc.c
@@ -2706,8 +2706,11 @@
if (!drm_core_check_feature(dev, DRIVER_MODESET))
return -EINVAL;
- /* For some reason crtc x/y offsets are signed internally. */
- if (crtc_req->x > INT_MAX || crtc_req->y > INT_MAX)
+ /*
+ * Universal plane src offsets are only 16.16, prevent havoc for
+ * drivers using universal plane code internally.
+ */
+ if (crtc_req->x & 0xffff0000 || crtc_req->y & 0xffff0000)
return -ERANGE;
drm_modeset_lock_all(dev);