From patchwork Fri Mar 5 12:21:47 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg Kroah-Hartman X-Patchwork-Id: 394370 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=-18.8 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER, INCLUDES_PATCH, MAILING_LIST_MULTI, SPF_HELO_NONE, SPF_PASS, URIBL_BLOCKED, USER_AGENT_GIT 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 2684BC4332D for ; Fri, 5 Mar 2021 12:35:31 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 14DB76501F for ; Fri, 5 Mar 2021 12:35:31 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231751AbhCEMfD (ORCPT ); Fri, 5 Mar 2021 07:35:03 -0500 Received: from mail.kernel.org ([198.145.29.99]:46402 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231860AbhCEMen (ORCPT ); Fri, 5 Mar 2021 07:34:43 -0500 Received: by mail.kernel.org (Postfix) with ESMTPSA id 510676501D; Fri, 5 Mar 2021 12:34:40 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1614947681; bh=/KBQUc3XBQeTdmbwSV/TnNC2PL+nXl0zvygNZc+Jvlk=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=bXTlT+23k2cbt5j9HHoDq0F/mXLuo5h5yZ328uMFC/dJe8c9zVqGS0JGcjOF4wA5i PpMpozYm7kwlguE+KhSA5nTHm9LkdQMi0LQtXU3eDCJ101NPxVpG2tr8sytYQbTlmX 6JsCKFu71vbEbyZ5zC8aVMBTjXMB7zcpYoaCUgIU= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Daniel Wheeler , Nicholas Kazlauskas , Eric Yang , Anson Jacob , Alex Deucher , Sasha Levin Subject: [PATCH 5.4 45/72] drm/amd/display: Guard against NULL pointer deref when get_i2c_info fails Date: Fri, 5 Mar 2021 13:21:47 +0100 Message-Id: <20210305120859.550735603@linuxfoundation.org> X-Mailer: git-send-email 2.30.1 In-Reply-To: <20210305120857.341630346@linuxfoundation.org> References: <20210305120857.341630346@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: stable@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 fa92b88bc5a1..40041c61a100 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));