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=-16.7 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,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 15C32C433E0 for ; Tue, 23 Feb 2021 19:22:46 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id CBD9764DF3 for ; Tue, 23 Feb 2021 19:22:45 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231865AbhBWTWQ (ORCPT ); Tue, 23 Feb 2021 14:22:16 -0500 Received: from youngberry.canonical.com ([91.189.89.112]:55181 "EHLO youngberry.canonical.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231895AbhBWTUD (ORCPT ); Tue, 23 Feb 2021 14:20:03 -0500 Received: from 1.general.cking.uk.vpn ([10.172.193.212] helo=localhost) by youngberry.canonical.com with esmtpsa (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.86_2) (envelope-from ) id 1lEdDC-0007ll-2R; Tue, 23 Feb 2021 19:19:10 +0000 From: Colin King To: Jani Nikula , Joonas Lahtinen , Rodrigo Vivi , David Airlie , Daniel Vetter , Ramalingam C , Anshuman Gupta , intel-gfx@lists.freedesktop.org, dri-devel@lists.freedesktop.org Cc: kernel-janitors@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH][next] drm/i915/hdcp: Fix null pointer dereference of connector->encoder Date: Tue, 23 Feb 2021 19:19:09 +0000 Message-Id: <20210223191909.16682-1-colin.king@canonical.com> X-Mailer: git-send-email 2.30.0 MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Colin Ian King The recent commit 6c63e6e14da7 ("drm/i915/hdcp: No HDCP when encoder is't initialized") added a null pointer check on connector->encoder hence implying that it could potentially be null. This means that the initialization of dig_port via the call intel_attached_dig_port may cause a null pointer dereference on connector->encoder. Fix this by only assigning dig_port after a null check has been performed on connector->encoder. Addresses-Coverity: ("Dereference before null check") Fixes: 36e5e7042b20 ("drm/i915: Don't fully disable HDCP on a port if multiple pipes are using it") Signed-off-by: Colin Ian King --- drivers/gpu/drm/i915/display/intel_hdcp.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/drivers/gpu/drm/i915/display/intel_hdcp.c b/drivers/gpu/drm/i915/display/intel_hdcp.c index ae1371c36a32..7525ea31766c 100644 --- a/drivers/gpu/drm/i915/display/intel_hdcp.c +++ b/drivers/gpu/drm/i915/display/intel_hdcp.c @@ -2260,7 +2260,7 @@ int intel_hdcp_enable(struct intel_connector *connector, const struct intel_crtc_state *pipe_config, u8 content_type) { struct drm_i915_private *dev_priv = to_i915(connector->base.dev); - struct intel_digital_port *dig_port = intel_attached_dig_port(connector); + struct intel_digital_port *dig_port; struct intel_hdcp *hdcp = &connector->hdcp; unsigned long check_link_interval = DRM_HDCP_CHECK_PERIOD_MS; int ret = -EINVAL; @@ -2274,6 +2274,7 @@ int intel_hdcp_enable(struct intel_connector *connector, return -ENODEV; } + dig_port = intel_attached_dig_port(connector); mutex_lock(&hdcp->mutex); mutex_lock(&dig_port->hdcp_mutex); drm_WARN_ON(&dev_priv->drm, -- 2.30.0