imx-drm: imx-drm-core: improve safety of imx_drm_add_crtc()
We must not add more CRTCs than we have declared to the vblank
helpers, otherwise we overflow their arrays. Force failure if we
exceed the number of CRTCs.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Acked-by: Sascha Hauer <s.hauer@pengutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff --git a/drivers/staging/imx-drm/imx-drm-core.c b/drivers/staging/imx-drm/imx-drm-core.c
index 19e431d..96e4eee 100644
--- a/drivers/staging/imx-drm/imx-drm-core.c
+++ b/drivers/staging/imx-drm/imx-drm-core.c
@@ -501,6 +501,15 @@
mutex_lock(&imxdrm->mutex);
+ /*
+ * The vblank arrays are dimensioned by MAX_CRTC - we can't
+ * pass IDs greater than this to those functions.
+ */
+ if (imxdrm->pipes >= MAX_CRTC) {
+ ret = -EINVAL;
+ goto err_busy;
+ }
+
if (imxdrm->drm->open_count) {
ret = -EBUSY;
goto err_busy;
