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=-19.0 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=unavailable 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 4DA2DC4361B for ; Wed, 24 Feb 2021 13:43:42 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 19862601FB for ; Wed, 24 Feb 2021 13:43:42 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S237733AbhBXNmo (ORCPT ); Wed, 24 Feb 2021 08:42:44 -0500 Received: from mail.kernel.org ([198.145.29.99]:58442 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235714AbhBXNFD (ORCPT ); Wed, 24 Feb 2021 08:05:03 -0500 Received: by mail.kernel.org (Postfix) with ESMTPSA id 8E5F664F80; Wed, 24 Feb 2021 12:54:05 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1614171246; bh=EomfylCSApmaTvl+siIcJT0taEri7bkI5Dnz8wQmmE0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=mABoQ9uNJ4N1RkJUm7MSqbpT1ohqu+G7EokN9qpijd+lIwK2rLisUIPHV4cx5wuHR zTHOfX/MQ8YeLGlvwBjqk2nG2gwUsMwRUFvPUiFyvaWFIdMZny/vZHUtxESmXhv+uS 7ELQlrwLMLxaiwT4Flo0iGZYjDyHg0Lnl+sqE+clpDygF00BYUB2gCmUJFQX4TWDcB rYwQ6nPVdwgnmW/PeQ+QPIAsBW+IGLYyxLvU0zZMBZGf0XGeo3leTyWhOHgkgG0fNQ CieAK8TAo+fE/SCEPkxXq14jfpVPpfRgH9Azh3gL9W9NNl4dQpo/vW6nb/EjaG+fkC bVLNqDKFyNe4Q== From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Nicholas Kazlauskas , Daniel Wheeler , Eric Yang , Anson Jacob , Alex Deucher , Sasha Levin , amd-gfx@lists.freedesktop.org, dri-devel@lists.freedesktop.org Subject: [PATCH AUTOSEL 5.4 19/40] drm/amd/display: Guard against NULL pointer deref when get_i2c_info fails Date: Wed, 24 Feb 2021 07:53:19 -0500 Message-Id: <20210224125340.483162-19-sashal@kernel.org> X-Mailer: git-send-email 2.27.0 In-Reply-To: <20210224125340.483162-1-sashal@kernel.org> References: <20210224125340.483162-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Nicholas Kazlauskas [ Upstream commit 44a09e3d95bd2b7b0c224100f78f335859c4e193 ] [Why] If the BIOS table is invalid or corrupt then get_i2c_info can fail and we dereference a NULL pointer. [How] Check that ddc_pin is not NULL before using it and log an error if it is because this is unexpected. Tested-by: Daniel Wheeler Signed-off-by: Nicholas Kazlauskas Reviewed-by: Eric Yang Acked-by: Anson Jacob Signed-off-by: Alex Deucher Signed-off-by: Sasha Levin --- drivers/gpu/drm/amd/display/dc/core/dc_link.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/drivers/gpu/drm/amd/display/dc/core/dc_link.c b/drivers/gpu/drm/amd/display/dc/core/dc_link.c index fa92b88bc5a13..40041c61a100e 100644 --- a/drivers/gpu/drm/amd/display/dc/core/dc_link.c +++ b/drivers/gpu/drm/amd/display/dc/core/dc_link.c @@ -1303,6 +1303,11 @@ static bool construct( goto ddc_create_fail; } + if (!link->ddc->ddc_pin) { + DC_ERROR("Failed to get I2C info for connector!\n"); + goto ddc_create_fail; + } + link->ddc_hw_inst = dal_ddc_get_line( dal_ddc_service_get_ddc_pin(link->ddc)); -- 2.27.0