Validate requested pixel format against bits_per_pixel to reject
invalid formats with subcomponents length sum is greater than requested
bits_per_pixel.
weston 5.0.0 with fbdev backend tries to set up an ARGB x8r8g8b8 pixel
format without bits_per_pixel updating. So it can request
x8r8g8b8 with 16 bpp which is obviously incorrect and should be
rejected.
Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Eugeniy Paltsev <Eugeniy.Paltsev@xxxxxxxxxxxx>
---
drivers/gpu/drm/drm_fb_helper.c | 7 +++++++
1 file changed, 7 insertions(+)
diff --git a/drivers/gpu/drm/drm_fb_helper.c b/drivers/gpu/drm/drm_fb_helper.c
index 16ec93b75dbf..4f39da07f053 100644
--- a/drivers/gpu/drm/drm_fb_helper.c
+++ b/drivers/gpu/drm/drm_fb_helper.c
@@ -1610,6 +1610,13 @@ int drm_fb_helper_check_var(struct fb_var_screeninfo *var,
return -EINVAL;
}
+ if ((var->green.length + var->blue.length + var->red.length +
+ var->transp.length) > var->bits_per_pixel) {
+ DRM_DEBUG("fb requested pixel format can't fit in %d bpp\n",
+ var->bits_per_pixel);
+ return -EINVAL;
+ }
+
switch (var->bits_per_pixel) {
case 16:
depth = (var->green.length == 6) ? 16 : 15;
--
2.14.4
