From patchwork Wed Jan 29 23:24:48 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: "Souza, Jose" X-Patchwork-Id: 11357043 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 09BD792A for ; Wed, 29 Jan 2020 23:25:06 +0000 (UTC) Received: from gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id E65B6206D5 for ; Wed, 29 Jan 2020 23:25:05 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org E65B6206D5 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=intel.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=dri-devel-bounces@lists.freedesktop.org Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 1FDA06E462; Wed, 29 Jan 2020 23:25:03 +0000 (UTC) X-Original-To: dri-devel@lists.freedesktop.org Delivered-To: dri-devel@lists.freedesktop.org Received: from mga03.intel.com (mga03.intel.com [134.134.136.65]) by gabe.freedesktop.org (Postfix) with ESMTPS id 9860E6E462; Wed, 29 Jan 2020 23:25:01 +0000 (UTC) X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga001.fm.intel.com ([10.253.24.23]) by orsmga103.jf.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 29 Jan 2020 15:25:00 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.70,379,1574150400"; d="scan'208";a="316345184" Received: from josouza-mobl.jf.intel.com (HELO josouza-MOBL.intel.com) ([10.24.13.17]) by fmsmga001.fm.intel.com with ESMTP; 29 Jan 2020 15:25:00 -0800 From: =?utf-8?q?Jos=C3=A9_Roberto_de_Souza?= To: dri-devel@lists.freedesktop.org Subject: [PATCH] drm/mst: Fix possible NULL pointer dereference in drm_dp_mst_process_up_req() Date: Wed, 29 Jan 2020 15:24:48 -0800 Message-Id: <20200129232448.84704-1-jose.souza@intel.com> X-Mailer: git-send-email 2.25.0 MIME-Version: 1.0 X-BeenThere: dri-devel@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Direct Rendering Infrastructure - Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Sean Paul , intel-gfx@lists.freedesktop.org, =?utf-8?q?Jos=C3=A9_Roberto_de_Souza?= Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" According to DP specification, DP_SINK_EVENT_NOTIFY is also a broadcast message but as this function only handles DP_CONNECTION_STATUS_NOTIFY I will only make the static analyzer that caught this issue happy by not calling drm_dp_get_mst_branch_device_by_guid() with a NULL guid, causing drm_dp_mst_process_up_req() to return in the "if (!mstb)" right bellow. Fixes: 9408cc94eb04 ("drm/dp_mst: Handle UP requests asynchronously") Cc: Lyude Paul Cc: Sean Paul Signed-off-by: José Roberto de Souza Reviewed-by: Stanislav Lisovskiy Reviewed-by: Lyude Paul --- drivers/gpu/drm/drm_dp_mst_topology.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/drivers/gpu/drm/drm_dp_mst_topology.c b/drivers/gpu/drm/drm_dp_mst_topology.c index 23cf46bfef74..a811247cecfe 100644 --- a/drivers/gpu/drm/drm_dp_mst_topology.c +++ b/drivers/gpu/drm/drm_dp_mst_topology.c @@ -3829,7 +3829,8 @@ drm_dp_mst_process_up_req(struct drm_dp_mst_topology_mgr *mgr, else if (msg->req_type == DP_RESOURCE_STATUS_NOTIFY) guid = msg->u.resource_stat.guid; - mstb = drm_dp_get_mst_branch_device_by_guid(mgr, guid); + if (guid) + mstb = drm_dp_get_mst_branch_device_by_guid(mgr, guid); } else { mstb = drm_dp_get_mst_branch_device(mgr, hdr->lct, hdr->rad); }