From patchwork Wed Mar 11 13:00:06 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Heikki Krogerus X-Patchwork-Id: 11431693 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 A8A8B138D for ; Wed, 11 Mar 2020 13:00:14 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 86CB222522 for ; Wed, 11 Mar 2020 13:00:14 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729501AbgCKNAN (ORCPT ); Wed, 11 Mar 2020 09:00:13 -0400 Received: from mga05.intel.com ([192.55.52.43]:34246 "EHLO mga05.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729358AbgCKNAN (ORCPT ); Wed, 11 Mar 2020 09:00:13 -0400 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga001.fm.intel.com ([10.253.24.23]) by fmsmga105.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 11 Mar 2020 06:00:13 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.70,540,1574150400"; d="scan'208";a="353878533" Received: from black.fi.intel.com (HELO black.fi.intel.com.) ([10.237.72.28]) by fmsmga001.fm.intel.com with ESMTP; 11 Mar 2020 06:00:11 -0700 From: Heikki Krogerus To: Greg Kroah-Hartman Cc: Hans de Goede , linux-usb@vger.kernel.org, stable@vger.kernel.org Subject: [PATCH 2/2] usb: typec: ucsi: displayport: Fix a potential race during registration Date: Wed, 11 Mar 2020 16:00:06 +0300 Message-Id: <20200311130006.41288-3-heikki.krogerus@linux.intel.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20200311130006.41288-1-heikki.krogerus@linux.intel.com> References: <20200311130006.41288-1-heikki.krogerus@linux.intel.com> MIME-Version: 1.0 Sender: linux-usb-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-usb@vger.kernel.org Locking the connector in ucsi_register_displayport() to make sure that nothing can access the displayport alternate mode before the function has finished and the alternate mode is actually ready. Fixes: af8622f6a585 ("usb: typec: ucsi: Support for DisplayPort alt mode") Cc: stable@vger.kernel.org Signed-off-by: Heikki Krogerus --- drivers/usb/typec/ucsi/displayport.c | 9 ++++++++- 1 file changed, 8 insertions(+), 1 deletion(-) diff --git a/drivers/usb/typec/ucsi/displayport.c b/drivers/usb/typec/ucsi/displayport.c index 261131c9e37c..048381c058a5 100644 --- a/drivers/usb/typec/ucsi/displayport.c +++ b/drivers/usb/typec/ucsi/displayport.c @@ -288,6 +288,8 @@ struct typec_altmode *ucsi_register_displayport(struct ucsi_connector *con, struct typec_altmode *alt; struct ucsi_dp *dp; + mutex_lock(&con->lock); + /* We can't rely on the firmware with the capabilities. */ desc->vdo |= DP_CAP_DP_SIGNALING | DP_CAP_RECEPTACLE; @@ -296,12 +298,15 @@ struct typec_altmode *ucsi_register_displayport(struct ucsi_connector *con, desc->vdo |= all_assignments << 16; alt = typec_port_register_altmode(con->port, desc); - if (IS_ERR(alt)) + if (IS_ERR(alt)) { + mutex_unlock(&con->lock); return alt; + } dp = devm_kzalloc(&alt->dev, sizeof(*dp), GFP_KERNEL); if (!dp) { typec_unregister_altmode(alt); + mutex_unlock(&con->lock); return ERR_PTR(-ENOMEM); } @@ -314,5 +319,7 @@ struct typec_altmode *ucsi_register_displayport(struct ucsi_connector *con, alt->ops = &ucsi_displayport_ops; typec_altmode_set_drvdata(alt, dp); + mutex_unlock(&con->lock); + return alt; }