drm/edid: Fix potential memory leak in edid_load()

Do not leak memory by updating pointer with potentially
NULL realloc return value.

Found by Linux Driver Verification project (linuxtesting.org).

Signed-off-by: Alexey Khoroshilov <khoroshilov@ispras.ru>
Reviewed-by: Carsten Emde <C.Emde@osadl.org>
Signed-off-by: Dave Airlie <airlied@redhat.com>

diff --git a/drivers/gpu/drm/drm_edid_load.c b/drivers/gpu/drm/drm_edid_load.c
index 66d4a28ad5a23fc2cf4b7b745091296444e287b1..0303935d10e2ca45165509a7e9e8165962c99774 100644 (file)
--- a/drivers/gpu/drm/drm_edid_load.c
+++ b/drivers/gpu/drm/drm_edid_load.c
@@ -119,7 +119,7 @@ static int edid_load(struct drm_connector *connector, char *name,
 {
        const struct firmware *fw;
        struct platform_device *pdev;
-       u8 *fwdata = NULL, *edid;
+       u8 *fwdata = NULL, *edid, *new_edid;
        int fwsize, expected;
        int builtin = 0, err = 0;
        int i, valid_extensions = 0;
@@ -195,12 +195,14 @@ static int edid_load(struct drm_connector *connector, char *name,
                    "\"%s\" for connector \"%s\"\n", valid_extensions,
                    edid[0x7e], name, connector_name);
                edid[0x7e] = valid_extensions;
-               edid = krealloc(edid, (valid_extensions + 1) * EDID_LENGTH,
+               new_edid = krealloc(edid, (valid_extensions + 1) * EDID_LENGTH,
                    GFP_KERNEL);
-               if (edid == NULL) {
+               if (new_edid == NULL) {
                        err = -ENOMEM;
+                       kfree(edid);
                        goto relfw_out;
                }
+               edid = new_edid;
        }
 
        connector->display_info.raw_edid = edid;