Re: [PATCH] drm/gma500: fix a possible null pointer dereference

From: Markus Elfring
Date: Sat Jun 22 2024 - 11:09:25 EST


> In cdv_intel_lvds_get_modes(), the return value of drm_mode_duplicate()
> is assigned to mode, which will lead to a NULL pointer dereference on
> failure of drm_mode_duplicate(). Add a check to avoid npd.

1. Can a wording approach (like the following) be a better change description?

A null pointer is stored in the local variable “mode” after a call
of the function “drm_mode_duplicate” failed. This pointer was passed to
a subsequent call of the function “drm_mode_probed_add” where an undesirable
dereference will be performed then.
Thus add a corresponding return value check.


2. Would you like to add any tags (like “Fixes”) accordingly?


3. How do you think about to use a summary phrase like “Avoid null pointer dereference
in cdv_intel_lvds_get_modes()”?

Regards,
Markus