| Message ID | 1436257310-4388-1-git-send-email-zhjwpku@gmail.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Tue, Jul 07, 2015 at 04:21:50PM +0800, John Hunter wrote: > From: Zhao Junwang <zhjwpku@gmail.com> > > 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 > > Cc: Daniel Vetter <daniel.vetter@ffwll.ch> > Signed-off-by: Zhao Junwang <zhjwpku@gmail.com> > --- > drivers/gpu/drm/drm_crtc.c | 7 +++++-- > 1 file changed, 5 insertions(+), 2 deletions(-) > > diff --git a/drivers/gpu/drm/drm_crtc.c b/drivers/gpu/drm/drm_crtc.c > index b69ed97..c307435 100644 > --- a/drivers/gpu/drm/drm_crtc.c > +++ b/drivers/gpu/drm/drm_crtc.c > @@ -2706,8 +2706,11 @@ 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) > + /* > + * Legacy setcrtc ioctl does take a 32 bit value which might > + * overflow That legacy takes 32bit is clear, the important part to mention is that atomic only takes a 16.16 fixed point for this. And to avoid surprises in for atomic drivers it's better to check this here. Actually this even holds for just universal planes, no need for full-blown atomic. So what about instead /* * Universal lane src offsets are only 16.16, prevent havoc for * drivers using universal plane code internally. */ -Daniel > + */ > + if (crtc_req->x & 0xffff0000 || crtc_req->y & 0xffff0000) > return -ERANGE; > > drm_modeset_lock_all(dev); > -- > 1.7.10.4 > > > _______________________________________________ > dri-devel mailing list > dri-devel@lists.freedesktop.org > http://lists.freedesktop.org/mailman/listinfo/dri-devel
diff --git a/drivers/gpu/drm/drm_crtc.c b/drivers/gpu/drm/drm_crtc.c index b69ed97..c307435 100644 --- a/drivers/gpu/drm/drm_crtc.c +++ b/drivers/gpu/drm/drm_crtc.c @@ -2706,8 +2706,11 @@ 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) + /* + * Legacy setcrtc ioctl does take a 32 bit value which might + * overflow + */ + if (crtc_req->x & 0xffff0000 || crtc_req->y & 0xffff0000) return -ERANGE; drm_modeset_lock_all(dev);