From: =?UTF-8?q?Ville=20Syrj=C3=A4l=C3=A4?= <ville.syrjala@linux.intel.com>
Date: Fri, 2 Mar 2018 16:03:00 +0200
Subject: drm: Check property/enum name length
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Git-commit: 5ebbb5b4d424e030b7d240ce71767c4145c7f26e
Patch-mainline: v4.17-rc1
References: FATE#326289 FATE#326079 FATE#326049 FATE#322398 FATE#326166

Reject requests to add properties/enums with an overly long name.
Previously we would have just silently truncated the string and exposed
it userspace.

v2: drm_property_create() returns a pointer

Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180302140300.31110-1-ville.syrjala@linux.intel.com
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Acked-by: Petr Tesarik <ptesarik@suse.com>
---
 drivers/gpu/drm/drm_property.c |    6 ++++++
 1 file changed, 6 insertions(+)

--- a/drivers/gpu/drm/drm_property.c
+++ b/drivers/gpu/drm/drm_property.c
@@ -78,6 +78,9 @@ struct drm_property *drm_property_create
 	struct drm_property *property = NULL;
 	int ret;
 
+	if (WARN_ON(strlen(name) >= DRM_PROP_NAME_LEN))
+		return NULL;
+
 	property = kzalloc(sizeof(struct drm_property), GFP_KERNEL);
 	if (!property)
 		return NULL;
@@ -372,6 +375,9 @@ int drm_property_add_enum(struct drm_pro
 {
 	struct drm_property_enum *prop_enum;
 
+	if (WARN_ON(strlen(name) >= DRM_PROP_NAME_LEN))
+		return -EINVAL;
+
 	if (!(drm_property_type_is(property, DRM_MODE_PROP_ENUM) ||
 			drm_property_type_is(property, DRM_MODE_PROP_BITMASK)))
 		return -EINVAL;