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>

1 files changed, 5 insertions, 3 deletions

diff --git a/drivers/gpu/drm/drm_edid_load.c b/drivers/gpu/drm/drm_edid_load.c
index 66d4a28ad5a2..0303935d10e2 100644
--- 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;