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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id B710EC433F5 for ; Tue, 17 May 2022 10:09:48 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1343620AbiEQKJp (ORCPT ); Tue, 17 May 2022 06:09:45 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:60808 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1343797AbiEQKG4 (ORCPT ); Tue, 17 May 2022 06:06:56 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id CB71213D6C; Tue, 17 May 2022 03:06:53 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 668B961517; Tue, 17 May 2022 10:06:53 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 0FF4FC385B8; Tue, 17 May 2022 10:06:51 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1652782012; bh=NMoilscLmc4PgSYU3AERGYXDODbll8nGlk8mFWQ/E+Q=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=VDBl6/O+U+ffk25lnOuexCCDsFAZIusrbJup1PFWyJtlhRwaXWmv+h5JNiHWdoJpT XNddlZSGY0izGxPw45GFl9BAJkwVN8bhlBpOEwq+jIQfC3f/0ooWEUZNxvGTtoIoqP Oj8ffsrSXAsvmqwRzSwcO8aDd7iW46/PfQ0x/NGc= Date: Tue, 17 May 2022 12:06:47 +0200 From: Greg KH To: Yuanjun Gong Cc: Alex Deucher , Christian =?iso-8859-1?Q?K=F6nig?= , amd-gfx@lists.freedesktop.org, linux-kernel@vger.kernel.org, stable@vger.kernel.org Subject: Re: [PATCH 1/1] radeon: fix a possible null pointer dereference Message-ID: References: <20220517095700.7291-1-ruc_gongyuanjun@163.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20220517095700.7291-1-ruc_gongyuanjun@163.com> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, May 17, 2022 at 05:57:00PM +0800, Yuanjun Gong wrote: > From: Gong Yuanjun > > In radeon_fp_native_mode(), 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. > > The failure status of drm_cvt_mode() on the other path is checked too. > > Signed-off-by: Gong Yuanjun > --- > drivers/gpu/drm/radeon/radeon_connectors.c | 4 ++++ > 1 file changed, 4 insertions(+) > > diff --git a/drivers/gpu/drm/radeon/radeon_connectors.c b/drivers/gpu/drm/radeon/radeon_connectors.c > index 0cb1345c6ba4..fabe4f4ca124 100644 > --- a/drivers/gpu/drm/radeon/radeon_connectors.c > +++ b/drivers/gpu/drm/radeon/radeon_connectors.c > @@ -473,6 +473,8 @@ static struct drm_display_mode *radeon_fp_native_mode(struct drm_encoder *encode > native_mode->vdisplay != 0 && > native_mode->clock != 0) { > mode = drm_mode_duplicate(dev, native_mode); > + if (!mode) > + return NULL; > mode->type = DRM_MODE_TYPE_PREFERRED | DRM_MODE_TYPE_DRIVER; > drm_mode_set_name(mode); > > @@ -487,6 +489,8 @@ static struct drm_display_mode *radeon_fp_native_mode(struct drm_encoder *encode > * simpler. > */ > mode = drm_cvt_mode(dev, native_mode->hdisplay, native_mode->vdisplay, 60, true, false, false); > + if (!mode) > + return NULL; > mode->type = DRM_MODE_TYPE_PREFERRED | DRM_MODE_TYPE_DRIVER; > DRM_DEBUG_KMS("Adding cvt approximation of native panel mode %s\n", mode->name); > } > -- > 2.17.1 > This is not the correct way to submit patches for inclusion in the stable kernel tree. Please read: https://www.kernel.org/doc/html/latest/process/stable-kernel-rules.html for how to do this properly.