drm/atomic: verify that gamma/degamma LUTs are not too big

The kernel specifies LUT table sizes in a separate property, however it
doesn't enforce it as a maximum. Some drivers implement max size check
on their own in the atomic_check path. Other drivers simply ignore the
issue. Perform LUT size validation in the generic place.

Reviewed-by: Thomas Zimmermann <tzimmermann@suse.de>
Link: https://patch.msgid.link/20260106-drm-fix-lut-checks-v3-3-f7f979eb73c8@oss.qualcomm.com
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@oss.qualcomm.com>

Author: lumag

drivers/gpu/drm/drm_atomic_uapi.c

@@ -413,10 +413,19 @@ static int drm_atomic_crtc_set_property(struct drm_crtc *crtc,
 	} else if (property == config->prop_vrr_enabled) {
 		state->vrr_enabled = val;
 	} else if (property == config->degamma_lut_property) {
+		const size_t elem_size = sizeof(struct drm_color_lut);
+		u64 lut_size;
+
+		ret = drm_object_immutable_property_get_value(&crtc->base,
+							      config->degamma_lut_size_property,
+							      &lut_size);
+		if (ret)
+			return ret;
+
 		ret = drm_property_replace_blob_from_id(dev,
 					&state->degamma_lut,
 					val,
-					-1, -1, sizeof(struct drm_color_lut),
+					elem_size * lut_size, -1, elem_size,
 					&replaced);
 		state->color_mgmt_changed |= replaced;
 		return ret;
@@ -429,10 +438,19 @@ static int drm_atomic_crtc_set_property(struct drm_crtc *crtc,
 		state->color_mgmt_changed |= replaced;
 		return ret;
 	} else if (property == config->gamma_lut_property) {
+		const size_t elem_size = sizeof(struct drm_color_lut);
+		u64 lut_size;
+
+		ret = drm_object_immutable_property_get_value(&crtc->base,
+							      config->gamma_lut_size_property,
+							      &lut_size);
+		if (ret)
+			return ret;
+
 		ret = drm_property_replace_blob_from_id(dev,
 					&state->gamma_lut,
 					val,
-					-1, -1, sizeof(struct drm_color_lut),
+					elem_size * lut_size, -1, elem_size,
 					&replaced);
 		state->color_mgmt_changed |= replaced;
 		return ret;