From 23e1ce89af5404c7a35dbd008ca85fb6adb16aad Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Ville=20Syrj=C3=A4l=C3=A4?= Date: Wed, 17 Dec 2014 13:56:24 +0200 Subject: [PATCH] drm: Do basic sanity checks for user modes MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Currently userspace is allowed to pass in basiclly any kind of garbage to setcrtc. Try to catch the cases where the timings make no sense by passing the mode through drm_mode_validate_basic(). One concern here is that we now start to block some modes that have worked in the past. It's at least possible with when using i915 with LVDS/eDP. Previously we've just ignored everything but hdisplay/vdisplay from the user mode and just overwritten the rest with the panel fixed mode. So if someone has been passing a mode with just those populated that would now stop working. If that is a real problem, we can't add these checks to the core code and each driver would have to have its own sanity checks. So fingers crossed... Signed-off-by: Ville Syrjälä Reviewed-by: Alex Deucher Signed-off-by: Daniel Vetter --- drivers/gpu/drm/drm_crtc.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/drivers/gpu/drm/drm_crtc.c b/drivers/gpu/drm/drm_crtc.c index 6700ebafef16..e3140c190556 100644 --- a/drivers/gpu/drm/drm_crtc.c +++ b/drivers/gpu/drm/drm_crtc.c @@ -2673,6 +2673,12 @@ int drm_mode_setcrtc(struct drm_device *dev, void *data, goto out; } + mode->status = drm_mode_validate_basic(mode); + if (mode->status != MODE_OK) { + ret = -EINVAL; + goto out; + } + drm_mode_set_crtcinfo(mode, CRTC_INTERLACE_HALVE_V); ret = drm_crtc_check_viewport(crtc, crtc_req->x, crtc_req->y,