From: Zhao Junwang Date: Tue, 7 Jul 2015 09:08:35 +0000 (+0800) Subject: drm: add a check for x/y in drm_mode_setcrtc X-Git-Tag: v3.2.71~34 X-Git-Url: http://git.hungrycats.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=270f492100ca2859f40cd39e758faa43e7754fe4;p=linux drm: add a check for x/y in drm_mode_setcrtc commit 01447e9f04ba1c49a9534ae6a5a6f26c2bb05226 upstream. 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 Signed-off-by: Zhao Junwang Signed-off-by: Daniel Vetter Signed-off-by: Ben Hutchings --- diff --git a/drivers/gpu/drm/drm_crtc.c b/drivers/gpu/drm/drm_crtc.c index 0e716fd2cb89..20110b4ad791 100644 --- a/drivers/gpu/drm/drm_crtc.c +++ b/drivers/gpu/drm/drm_crtc.c @@ -1505,8 +1505,11 @@ int drm_mode_setcrtc(struct drm_device *dev, void *data, 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; mutex_lock(&dev->mode_config.mutex);