From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 58B56C46460 for ; Wed, 22 May 2019 14:52:20 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 2DF5320881 for ; Wed, 22 May 2019 14:52:20 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729689AbfEVOwT (ORCPT ); Wed, 22 May 2019 10:52:19 -0400 Received: from mga09.intel.com ([134.134.136.24]:58335 "EHLO mga09.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728450AbfEVOwT (ORCPT ); Wed, 22 May 2019 10:52:19 -0400 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga001.fm.intel.com ([10.253.24.23]) by orsmga102.jf.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 22 May 2019 07:52:18 -0700 X-ExtLoop1: 1 Received: from jnikula-mobl3.fi.intel.com (HELO localhost) ([10.237.66.150]) by fmsmga001.fm.intel.com with ESMTP; 22 May 2019 07:52:16 -0700 From: Jani Nikula To: Gen Zhang , sean@poorly.run Cc: linux-kernel@vger.kernel.org, dri-devel@lists.freedesktop.org Subject: Re: [PATCH] drm_edid-load: Fix a missing-check bug in drivers/gpu/drm/drm_edid_load.c In-Reply-To: <20190522123920.GB6772@zhanggen-UX430UQ> Organization: Intel Finland Oy - BIC 0357606-4 - Westendinkatu 7, 02160 Espoo References: <20190522123920.GB6772@zhanggen-UX430UQ> Date: Wed, 22 May 2019 17:55:35 +0300 Message-ID: <87o93u7d3s.fsf@intel.com> MIME-Version: 1.0 Content-Type: text/plain Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, 22 May 2019, Gen Zhang wrote: > In drm_load_edid_firmware(), fwstr is allocated by kstrdup(). And fwstr > is dereferenced in the following codes. However, memory allocation > functions such as kstrdup() may fail and returns NULL. Dereferencing > this null pointer may cause the kernel go wrong. Thus we should check > this kstrdup() operation. > Further, if kstrdup() returns NULL, we should return ERR_PTR(-ENOMEM) to > the caller site. strsep() handles the NULL pointer just fine, so there won't be a NULL dereference. However this patch seems like the right thing to do anyway. Reviewed-by: Jani Nikula > > Signed-off-by: Gen Zhang > > --- > diff --git a/drivers/gpu/drm/drm_edid_load.c b/drivers/gpu/drm/drm_edid_load.c > index a491509..a0e107a 100644 > --- a/drivers/gpu/drm/drm_edid_load.c > +++ b/drivers/gpu/drm/drm_edid_load.c > @@ -290,6 +290,8 @@ struct edid *drm_load_edid_firmware(struct drm_connector *connector) > * the last one found one as a fallback. > */ > fwstr = kstrdup(edid_firmware, GFP_KERNEL); > + if (!fwstr) > + return ERR_PTR(-ENOMEM); > edidstr = fwstr; > > while ((edidname = strsep(&edidstr, ","))) { > --- > _______________________________________________ > dri-devel mailing list > dri-devel@lists.freedesktop.org > https://lists.freedesktop.org/mailman/listinfo/dri-devel -- Jani Nikula, Intel Open Source Graphics Center