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=-2.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,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 B1F49C433F5 for ; Mon, 27 Aug 2018 19:43:10 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 7A662208B8 for ; Mon, 27 Aug 2018 19:43:10 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 7A662208B8 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=intel.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727490AbeH0XbH (ORCPT ); Mon, 27 Aug 2018 19:31:07 -0400 Received: from mga04.intel.com ([192.55.52.120]:5779 "EHLO mga04.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726826AbeH0XbG (ORCPT ); Mon, 27 Aug 2018 19:31:06 -0400 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga004.fm.intel.com ([10.253.24.48]) by fmsmga104.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 27 Aug 2018 12:43:07 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.53,296,1531810800"; d="scan'208";a="83833392" Received: from twinkler-lnx.jer.intel.com ([10.12.91.48]) by fmsmga004.fm.intel.com with ESMTP; 27 Aug 2018 12:43:05 -0700 From: Tomas Winkler To: Greg Kroah-Hartman Cc: Alexander Usyskin , linux-kernel@vger.kernel.org, Tomas Winkler , stable@vger.kernel.org Subject: [char-misc for 4.9 2/2] mei: bus: need to unlink client before freeing Date: Mon, 27 Aug 2018 22:40:16 +0300 Message-Id: <20180827194016.1287-3-tomas.winkler@intel.com> X-Mailer: git-send-email 2.14.4 In-Reply-To: <20180827194016.1287-1-tomas.winkler@intel.com> References: <20180827194016.1287-1-tomas.winkler@intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org In case a client fails to connect in mei_cldev_enable(), the caller won't call the mei_cldev_disable leaving the client in a linked stated. Upon driver unload the client structure will be freed in mei_cl_bus_dev_release(), leaving a stale pointer on a fail_list. This will eventually end up in crash during power down flow in mei_cl_set_disonnected(). RIP: mei_cl_set_disconnected+0x5/0x260[mei] Call trace: mei_cl_all_disconnect+0x22/0x30 mei_reset+0x194/0x250 __synchronize_hardirq+0x43/0x50 _cond_resched+0x15/0x30 mei_me_intr_clear+0x20/0x100 mei_stop+0x76/0xb0 mei_me_shutdown+0x3f/0x80 pci_device_shutdown+0x34/0x60 kernel_restart+0x0e/0x30 Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=200455 Fixes: 'c110cdb17148 ("mei: bus: make a client pointer always available")' Cc: 4.10+ Tested-by: Georg Müller Signed-off-by: Tomas Winkler --- drivers/misc/mei/bus.c | 9 ++++----- 1 file changed, 4 insertions(+), 5 deletions(-) diff --git a/drivers/misc/mei/bus.c b/drivers/misc/mei/bus.c index 13c6c9a2248a..fc3872fe7b25 100644 --- a/drivers/misc/mei/bus.c +++ b/drivers/misc/mei/bus.c @@ -521,17 +521,15 @@ int mei_cldev_enable(struct mei_cl_device *cldev) cl = cldev->cl; + mutex_lock(&bus->device_lock); if (cl->state == MEI_FILE_UNINITIALIZED) { - mutex_lock(&bus->device_lock); ret = mei_cl_link(cl); - mutex_unlock(&bus->device_lock); if (ret) - return ret; + goto out; /* update pointers */ cl->cldev = cldev; } - mutex_lock(&bus->device_lock); if (mei_cl_is_connected(cl)) { ret = 0; goto out; @@ -875,12 +873,13 @@ static void mei_cl_bus_dev_release(struct device *dev) mei_me_cl_put(cldev->me_cl); mei_dev_bus_put(cldev->bus); + mei_cl_unlink(cldev->cl); kfree(cldev->cl); kfree(cldev); } static const struct device_type mei_cl_device_type = { - .release = mei_cl_bus_dev_release, + .release = mei_cl_bus_dev_release, }; /** -- 2.14.4